[iOS features]- Summary

1. Don’t sleep on your phone

[UIApplication sharedApplication].idleTimerDisabled = YES;

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2. Hide a cell line

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {// if it is the row you need to hide, If (indexPath. Row == YouWantToHideRow) return 0; return 44; } // Then call [self.tableView beginUpdates] when you need to hide the cell; [self.tableView endUpdates];Copy the code

3. Disable Button highlighting

button.adjustsImageWhenHighlighted = NO; Or when creating a UIButton * button = [UIButton buttonWithType: UIButtonTypeCustom];Copy the code

4, Failed to obtain a cell from its dataSource

Your cell was called too early. The cell is first recycled and then created. Possible causes are as follows: 1. The xiB cell is not registered; 2. This cell is already cached in the memory (that is, the cell found through your cellId is not the type you want)

Cocoa Pods reported this error: Unable to access ‘Github.com/facebook/po…: Operation timed out after 0 milliseconds with 0 out of 0 bytes received

Solution: The cause may be a network problem. The network request timed out. You only need to retry

Cocoa Pods ERROR: While Executing gem… (Errno::EPERM)

Solution: https://segmentfault.com/q/1010000002926243

7. Animate the window root controller

// options are animation options [UIView transitionWithView:[UIApplication sharedApplication]. KeyWindow Duration: 0.5F options:UIViewAnimationOptionTransitionCrossDissolve animations:^{ BOOL oldState = [UIView areAnimationsEnabled]; [UIView setAnimationsEnabled:NO]; [UIApplication sharedApplication].keyWindow.rootViewController = [RootViewController new]; [UIView setAnimationsEnabled:oldState]; } completion:^(BOOL finished) { }];Copy the code

Remove duplicate objects from the array

NSArray * newArr = [oldArr valueForKeyPath: @ "@ distinctUnionOfObjects. Self"];Copy the code

9. Encountered during compilationNo such file or directory: / users/apple/XXX

Because the compile time, the file is not found under this path, to solve this problem, the first is to check if missing files in the project, if not in the engineering, needs from the local drag in, if it is found that already exist in engineering, or drag in or error, at this moment need to build phases in search the file, In this case, it is likely to search for two identical files, in this case, one path is correct, delete the other can be. If that still doesn’t work, delete both and drag the file back into the project

10, iOS8 system, tableView is best implemented under -tableView: heightForRowAtIndexPath: this proxy method, or in iOS8 may appear incomplete display or unable to respond to the event problem

11, iOS8 to achieve the sideslip function when this method must be implemented, or in iOS8 can not sideslip

/ / must write method, and use editActionsForRowAtIndexPath pairing, What don't write all right - (void) inside tableView: (UITableView *) tableView commitEditingStyle: (editingStyle UITableViewCellEditingStyle) forRowAtIndexPath:(NSIndexPath *)indexPath { }Copy the code

12. Three notices

NSSystemTimeZoneDidChangeNotification listening modification time interface of two buttons UIApplicationSignificantTimeChangeNotification state changes to monitor users to change the time (just click on Settings button is invoked automatically) NSSystemClockDidChangeNotification monitor user modification time (time different will call)

13. SDWebImage local caching can sometimes be harmful. If you have cached an image before, even if the server changes the image next time but the IMAGE URL is not changed, the image downloaded with sdWebImage will still be the same as before. Therefore, if you encounter this problem, do not first depress the server, just clear the cache and try again.

14. Note before going online:

1) delete all the test codes in the code 2), if there is a background audit mode, remind the background to open this mode 3), the main process run again 4), global search waring, check all marked waring places

15. Jump into app permission Settings

/ / into the app Settings if (UIApplicationOpenSettingsURLString! = NULL) { UIApplication *application = [UIApplication sharedApplication]; NSURL *URL = [NSURL URLWithString:UIApplicationOpenSettingsURLString]; if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) { [application openURL:URL options:@{} completionHandler:nil]; } else { [application openURL:URL]; }}Copy the code

16. Take a screenshot of the view

UIGraphicsBeginImageContextWithOptions (view. Bounds. The size, YES, 0.0); [view.layer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *img = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();Copy the code

17, if you want to dynamically modify the tableView tableHeaderView or tableFooterView height, need to reset the tableView, rather than directly change the height. The right thing to do is to reset the tableView. TableFooterView = changed the height of the view. Why is that? In fact, iOS8 above directly change the height is no problem, in iOS8 there is a problem with contentSize is not accurate, this is the solution.

18. Note that when an object is nil, the method that calls this object class does not execute

19, The content of the collectionView is not allowed to scroll when it is smaller than its width and height.

collectionView.alwaysBounceHorizontal = YES;
collectionView.alwaysBounceVertical = YES;

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20, Set the title color and size on the navigationBar

    [self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor youColor], NSFontAttributeName : [UIFont systemFontOfSize:15]}]

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21, color to picture

+ (UIImage *)cl_imageWithColor:(UIColor *)color {CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f); UIGraphicsBeginImageContext(rect.size); CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSetFillColorWithColor(context, [color CGColor]); CGContextFillRect(context, rect); UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return image; }Copy the code

22, View set rounded corners

#define ViewBorderRadius(View, Radius, Width, Color)\ \ [View.layer setCornerRadius:(Radius)]; \ [View.layer setMasksToBounds:YES]; \ [View.layer setBorderWidth:(Width)]; \ [view. layer setBorderColor:[Color CGColor]] // View rounded cornersCopy the code

23. Strong/weak references

#define WeakSelf(type)  __weak typeof(type) weak##type = type; // weak
#define StrongSelf(type)  __strong typeof(type) type = weak##type; // strong

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Convert radians from Angle

#define DegreesToRadian(x) (M_PI * (x) / 180Copy the code

25. Convert the Angle from radians

# define RadianToDegrees (radian) (radian * 180.0)/(M_PI)Copy the code

26. Access image resources

#define GetImage(imageName) [UIImage imageNamed:[NSString stringWithFormat:@"%@",imageName]]

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27. Obtain temp

#define PathTemp NSTemporaryDirectory()

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28, get sandbox Document

#define PathDocument [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject]

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29. Obtain the sandbox Cache

#define PathCache [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject]

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30. GCD code is executed only once

#define kDISPATCH_ONCE_BLOCK(onceBlock) static dispatch_once_t onceToken; dispatch_once(&onceToken, onceBlock);

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31. Customize NSLog

#ifdef DEBUG
#define NSLog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
#else
#define NSLog(...)
#endif

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32, the Font

#define FontL(s)             [UIFont systemFontOfSize:s weight:UIFontWeightLight]
#define FontR(s)             [UIFont systemFontOfSize:s weight:UIFontWeightRegular]
#define FontB(s)             [UIFont systemFontOfSize:s weight:UIFontWeightBold]
#define FontT(s)             [UIFont systemFontOfSize:s weight:UIFontWeightThin]
#define Font(s)              FontL(s)

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33 and the FORMAT

#define FORMAT(f, ...)      [NSString stringWithFormat:f, ## __VA_ARGS__]

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34. Run on the main thread

#define kDISPATCH_MAIN_THREAD(mainQueueBlock) dispatch_async(dispatch_get_main_queue(), mainQueueBlock);

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35. Enable asynchronous threads

#define kDISPATCH_GLOBAL_QUEUE_DEFAULT(globalQueueBlock) dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), globalQueueBlocl);

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36, notifications,

#define NOTIF_ADD(n, f) [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(f) name:n object:nil] #define NOTIF_POST(n,  o) [[NSNotificationCenter defaultCenter] postNotificationName:n object:o] #define NOTIF_REMV() [[NSNotificationCenter defaultCenter] removeObserver:self]Copy the code

37. Random colors

+ (UIColor *)RandomColor { NSInteger aRedValue = arc4random() % 255; NSInteger aGreenValue = arc4random() % 255; NSInteger aBlueValue = arc4random() % 255; UIColor *randColor = [UIColor colorWithRed:aRedValue / 255.0f Green :aGreenValue / 255.0F Blue :aBlueValue / 255.0F Alpha: 1.0 f]; return randColor; }Copy the code

38, Get window

+(UIWindow*)getWindow { UIWindow* win = nil; //[UIApplication sharedApplication].keyWindow; for (id item in [UIApplication sharedApplication].windows) { if ([item class] == [UIWindow class]) { if (! ((UIWindow*)item).hidden) { win = item; break; } } } return win; }Copy the code

39. Modify textField placeholder font color and size

[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
[textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];

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Put away the keyboard

[[[UIApplication sharedApplication] keyWindow] endEditing:YES];

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Control screen rotation, write in the controller

/** support automatic screen rotation */ - (BOOL)shouldAutorotate {return YES; } / what screen direction * / * * support - (UIInterfaceOrientationMask) supportedInterfaceOrientations {return UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight; } /** Default screen orientation (the current ViewController must be modally rendered by UIViewController (modally rendered with navigation invalid), Will call this method) * / - (UIInterfaceOrientation) preferredInterfaceOrientationForPresentation {return UIInterfaceOrientationLandscapeLeft | UIInterfaceOrientationLandscapeRight; }Copy the code

42. Get app cache size

- (CGFloat)getCachSize { NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize]; // Get a custom cache size // walk through the contents of a folder with an enumerator //1. Access to the folder the enumerator nsstrings * myCachePath = [NSHomeDirectory () stringByAppendingPathComponent: @ "Library/Caches"]. NSDirectoryEnumerator *enumerator = [[NSFileManager defaultManager] enumeratorAtPath:myCachePath]; __block NSUInteger count = 0; / / 2. Traversal for (nsstrings * fileName in enumerator) {nsstrings * path = [myCachePath stringByAppendingPathComponent: fileName]; NSDictionary *fileDict = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil]; count += fileDict.fileSize; CGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024; return totalSize; }Copy the code

43. Clear the APP cache

- (void)handleClearView {// Remove two parts //1. [[SDImageCache sharedImageCache] clearMemory]; // Clear the disk cache [[SDImageCache sharedImageCache] clearDisk]; / / 2. Delete your cache nsstrings * myCachePath = [NSHomeDirectory () stringByAppendingPathComponent: @ "Library/Caches"]. [[NSFileManager defaultManager] removeItemAtPath:myCachePath error:nil]; }Copy the code

Model to dictionary

static NSSet *classes; - (NSMutableDictionary *)getParameterDictionary { NSMutableDictionary *dict = [NSMutableDictionary dictionary]; Class c = self.class; while (c) { unsigned count; objc_property_t *properties = class_copyPropertyList([c class], &count); for (int i = 0; i < count; i++) { NSString *key = [NSString stringWithUTF8String:property_getName(properties[i])]; dict[key] = [self valueForKey:key]; } free(properties); // Get the parent class c = class_getSuperclass(c); if ([self isClassFromFoundation:c]) break; } return dict; } - (BOOL)isClassFromFoundation:(Class)c { if (c == [NSObject class] || c == [NSManagedObject class]) return YES; __block BOOL result = NO; [[self foundationClasses] enumerateObjectsUsingBlock:^(Class foundationClass, BOOL *stop) { if ([c isSubclassOfClass:foundationClass]) { result = YES; *stop = YES; } }]; return result; } - (NSSet *)foundationClasses {if (classes == nil) {// There is no NSObject in the set, because almost all classes inherit from NSObject, Classes = [NSSet setWithObjects: [NSURL class], [NSDate class], [NSValue class], [NSData class], [NSError class], [NSArray class], [NSDictionary class], [NSString class], [NSAttributedString class], nil]; } return classes; }Copy the code

45. Exchange two methods for implementation

Class aClass = [self class]; 

        SEL originalSelector = @selector(viewWillAppear:); 
        SEL swizzledSelector = @selector(xxx_viewWillAppear:); 

        Method originalMethod = class_getInstanceMethod(aClass, originalSelector); 
        Method swizzledMethod = class_getInstanceMethod(aClass, swizzledSelector); 

        BOOL didAddMethod = 
            class_addMethod(aClass, 
                originalSelector, 
                method_getImplementation(swizzledMethod), 
                method_getTypeEncoding(swizzledMethod)); 

        if (didAddMethod) { 
            class_replaceMethod(aClass, 
                swizzledSelector, 
                method_getImplementation(originalMethod), 
                method_getTypeEncoding(originalMethod)); 
        } else { 
            method_exchangeImplementations(originalMethod, swizzledMethod); 
        } 

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46. Print percent signs and quotation marks

    NSLog(@"%%");
    NSLog(@"\"");

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A few common permission judgment

If ([CLLocationManager authorizationStatus] = = kCLAuthorizationStatusDenied) {NSLog (@ positioning "no permission"); } AVAuthorizationStatus statusVideo = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo]; If (statusVideo = = AVAuthorizationStatusDenied) {NSLog (@ "no camera authority"); } / / is there a microphone permissions AVAuthorizationStatus statusAudio = [AVCaptureDevice authorizationStatusForMediaType: AVMediaTypeAudio]; If (statusAudio = = AVAuthorizationStatusDenied) {NSLog (@ "no recording authority"); } [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) { if (status == PHAuthorizationStatusDenied) { NSLog(@" no permission ");}}];Copy the code

48. Obtain the phone model

+ (NSString *)getDeviceInfo { struct utsname systemInfo; uname(&systemInfo); NSString *platform = [NSString stringWithCString:systemInfo.machine encoding:NSASCIIStringEncoding]; If ([platform isEqualToString:@"iPhone1,1"]) return @" iphone2g "; If ([platform isEqualToString:@"iPhone1,2"]) return @" iphone3g "; If ([platform isEqualToString:@"iPhone2,1"]) return @" iphone3gs "; If ([platform isEqualToString:@"iPhone3,1"]) return @" iphone4 "; If ([platform isEqualToString:@"iPhone3,2"]) return @" iphone4 "; If ([platform isEqualToString:@"iPhone3,3"]) return @" iphone4 "; If ([platform isEqualToString:@"iPhone4,1"]) return @" iphone4s "; If ([platform isEqualToString:@"iPhone5,1"]) return @"iPhone5 "; If ([platform isEqualToString:@"iPhone5,2"]) return @"iPhone5 "; If ([platform isEqualToString:@"iPhone5,3"]) return @" iphone5c "; If ([platform isEqualToString:@"iPhone5,4"]) return @" iphone5c "; If ([platform isEqualToString:@"iPhone6,1"]) return @" iphone5s "; If ([platform isEqualToString:@"iPhone6,2"]) return @" iphone5s "; If ([platform isEqualToString:@"iPhone7,1"]) return @" iphone6 Plus"; If ([platform isEqualToString:@"iPhone7,2"]) return @" iphone6 "; If ([platform isEqualToString:@"iPhone8,1"]) return @" iphone6s "; If ([platform isEqualToString:@"iPhone8,2"]) return @" iphone6s Plus"; If ([platform isEqualToString:@"iPhone9,1"]) return @" iphone7 "; if ([platform isEqualToString:@"iPhone9,1"]) return @" iphone7 "; If ([platform isEqualToString:@"iPhone9,2"]) return @" iphone7 Plus"; If ([platform isEqualToString:@"iPhone9,3"]) return @" iphone7 "; If ([platform isEqualToString:@"iPhone9,4"]) return @" iphone7 Plus"; if ([platform isEqualToString:@"iPhone9,4"]) return @" iphone7 Plus"; If ([platform isEqualToString:@"iPhone8,4"]) return @"iPhone SE"; If ([platform isEqualToString:@"iPod1,1"]) return @"iPod Touch 1G"; If ([platform isEqualToString:@"iPod2,1"]) return @"iPod Touch 2G"; If ([platform isEqualToString:@"iPod3,1"]) return @"iPod Touch 3G"; If ([platform isEqualToString:@"iPod4,1"]) return @"iPod Touch 4G"; If ([platform isEqualToString:@"iPod5,1"]) return @"iPod Touch 5G"; If ([platform isEqualToString:@"iPad1,1"]) return @"iPad 1G"; If ([platform isEqualToString:@"iPad2,1"]) return @"iPad2 "; If ([platform isEqualToString:@"iPad2,2"]) return @"iPad2 "; If ([platform isEqualToString:@"iPad2,3"]) return @"iPad2 "; If ([platform isEqualToString:@"iPad2,4"]) return @"iPad2 "; If ([platform isEqualToString:@"iPad2,5"]) return @"iPad Mini 1G"; If ([platform isEqualToString:@"iPad2,6"]) return @"iPad Mini 1G"; If ([platform isEqualToString:@"iPad2,7"]) return @"iPad Mini 1G"; If ([platform isEqualToString:@"iPad3,1"]) return @"iPad3 "; If ([platform isEqualToString:@"iPad3,2"]) return @"iPad3 "; If ([platform isEqualToString:@"iPad3,3"]) return @"iPad3 "; If ([platform isEqualToString:@"iPad3,4"]) return @" ipad4 "; If ([platform isEqualToString:@"iPad3,5"]) return @" ipad4 "; If ([platform isEqualToString:@"iPad3,6"]) return @" ipad4 "; If ([platform isEqualToString:@"iPad4,1"]) return @"iPad Air"; If ([platform isEqualToString:@"iPad4,2"]) return @"iPad Air"; If ([platform isEqualToString:@"iPad4,3"]) return @"iPad Air"; If ([platform isEqualToString:@"iPad4,4"]) return @"iPad Mini 2G"; If ([platform isEqualToString:@"iPad4,5"]) return @"iPad Mini 2G"; If ([platform isEqualToString:@"iPad4,6"]) return @"iPad Mini 2G"; if ([platform isEqualToString:@"i386"]) return @"iPhone Simulator"; if ([platform isEqualToString:@"x86_64"]) return @"iPhone Simulator"; return platform; }Copy the code

Long press copy function

- (void)viewDidLoad { [self.view addGestureRecognizer:[[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(pasteBoard:)]]; } - (void)pasteBoard:(UILongPressGestureRecognizer *)longPress { if (longPress.state == UIGestureRecognizerStateBegan) {  UIPasteboard *pasteboard = [UIPasteboard generalPasteboard]; Pasteboard. string = @" text to copy "; }}Copy the code

50. Cocoapods upgrade

Run sudo gem install -n /usr/local/bin cocoapods –pre on the terminal

51. After setting the startup page, the previous one is still displayed

Delete the app, reboot the phone, and reinstall it

Judge the type of picture

- (NSString *)contentTypeForImageData:(NSData *) Data {uint8_t c; [data getBytes:&c length:1]; switch (c) { case 0xFF: return @"jpeg"; case 0x89: return @"png"; case 0x47: return @"gif"; case 0x49: case 0x4D: return @"tiff"; case 0x52: if ([data length] < 12) { return nil; } NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(0, 12)] encoding:NSASCIIStringEncoding]; if ([testString hasPrefix:@"RIFF"] && [testString hasSuffix:@"WEBP"]) { return @"webp"; } return nil; } return nil; }Copy the code

53. Get phone and app information

NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary]; CFShow(infoDictionary); // app name NSString *app_Name = [infoDictionary objectForKey:@"CFBundleDisplayName"]; / / app versions nsstrings * app_Version = [infoDictionary objectForKey: @ "CFBundleShortVersionString"]. // app build version NSString *app_build = [infoDictionary objectForKey:@"CFBundleVersion"]; NSString* identifierNumber = [[UIDevice currentDevice] uniqueIdentifier]; NSLog(@" phone serial number: %@",identifierNumber); // Phone alias: user-defined name NSString* userPhoneName = [[UIDevice currentDevice] name]; NSLog(@" phone alias: %@", userPhoneName); // deviceName NSString* deviceName = [[UIDevice currentDevice] systemName]; NSLog(@" deviceName: %@",deviceName); // Mobile OS version NSString* phoneVersion = [[UIDevice currentDevice] systemVersion]; NSLog(@" Mobile OS version: %@", phoneVersion); NSString* phoneModel = [[UIDevice currentDevice] model]; NSLog(@" phoneModel: %@",phoneModel); NSString* localPhoneModel = [[UIDevice currentDevice] localizedModel]; NSLog(@" Internationalized locale name: %@",localPhoneModel); NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary]; NSString *appCurName = [infoDictionary objectForKey:@"CFBundleDisplayName"]; NSString *appCurName = [infoDictionary objectForKey:@"CFBundleDisplayName"]; NSLog(@" Current app name: %@",appCurName); / / the current application software version Such as: 1.0.1 nsstrings * appCurVersion = [infoDictionary objectForKey: @ "CFBundleShortVersionString"]. NSLog(@" Current application version :%@",appCurVersion); Int NSString *appCurVersionNum = [infoDictionary objectForKey:@"CFBundleVersion"]; // Current application version number int NSString *appCurVersionNum = [infoDictionary objectForKey:@"CFBundleVersion"]; NSLog(@" Current app version number: %@",appCurVersionNum);Copy the code

Get all attributes of a class

id LenderClass = objc_getClass("Lender");
unsigned int outCount, i;
objc_property_t *properties = class_copyPropertyList(LenderClass, &outCount);
for (i = 0; i < outCount; i++) {
    objc_property_t property = properties[i];
    fprintf(stdout, "%s %s\n", property_getName(property), property_getAttributes(property));
}

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55, image rounded corners

- (UIImage *) circleImage {/ / NO representative transparent UIGraphicsBeginImageContextWithOptions (self. The size, NO, 1); / / get the context CGContextRef CTX = UIGraphicsGetCurrentContext (); // Add a circle CGRect rect = CGRectMake(0, 0, self.size. Width, self.size. Height); / / square become circular CGContextAddEllipseInRect (CTX, the rect); / / cutting CGContextClip (CTX); // draw the image [self drawInRect:rect]; UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return image; }Copy the code

56. Image stretching

+ (UIImage *)resizableImage:(NSString *)imageName { UIImage *image = [UIImage imageNamed:imageName]; CGFloat imageW = image.size.width; CGFloat imageH = image.size.height; Return [image resizableImageWithCapInsets: UIEdgeInsetsMake (, imageW imageH * 0.5 * 0.5, imageH * 0.5, ImageW * 0.5) resizingMode: UIImageResizingModeStretch]; }Copy the code

JSON string to dictionary

+ (NSDictionary *)parseJSONStringToNSDictionary:(NSString *)JSONString {
    NSData *JSONData = [JSONString dataUsingEncoding:NSUTF8StringEncoding];
    NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableLeaves error:nil];
    return responseJSON;
}

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Identification number verification

- (BOOL)validateIdentityCard {
    BOOL flag;
    if (self.length <= 0) {
        flag = NO;
        return flag;
    }
    NSString *regex2 = @"^(\\d{14}|\\d{17})(\\d|[xX])$";
    NSPredicate *identityCardPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex2];
    return [identityCardPredicate evaluateWithObject:self];
}

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59. Obtain the MAC address of the device

+ (NSString *)macAddress { int mib[6]; size_t len; char *buf; unsigned char *ptr; struct if_msghdr *ifm; struct sockaddr_dl *sdl; mib[0] = CTL_NET; mib[1] = AF_ROUTE; mib[2] = 0; mib[3] = AF_LINK; mib[4] = NET_RT_IFLIST; if((mib[5] = if_nametoindex("en0")) == 0) { printf("Error: if_nametoindex error\n"); return NULL; } if(sysctl(mib, 6, NULL, &len, NULL, 0) < 0) { printf("Error: sysctl, take 1\n"); return NULL; } if((buf = malloc(len)) == NULL) { printf("Could not allocate memory. Rrror! \n"); return NULL; } if(sysctl(mib, 6, buf, &len, NULL, 0) < 0) { printf("Error: sysctl, take 2"); return NULL; } ifm = (struct if_msghdr *)buf; sdl = (struct sockaddr_dl *)(ifm + 1); ptr = (unsigned char *)LLADDR(sdl); NSString *outstring = [NSString stringWithFormat:@"%02X:%02X:%02X:%02X:%02X:%02X", *ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)]; free(buf); return outstring; }Copy the code

60. Import the custom font library

2. Add a line of array “Fonts provided by Application” to the plist of the project. Add an item to this key and its value is the TTF file name that you imported. Font = [UIFont fontWithName:@” TTF file name “size:20.0];

Get the controller that is currently displayed, whether it is pushed or presented

- (UIViewController *)getVisibleViewControllerFrom:(UIViewController*)vc { if ([vc isKindOfClass:[UINavigationController  class]]) { return [self getVisibleViewControllerFrom:[((UINavigationController*) vc) visibleViewController]]; }else if ([vc isKindOfClass:[UITabBarController class]]){ return [self getVisibleViewControllerFrom:[((UITabBarController*) vc) selectedViewController]]; } else { if (vc.presentedViewController) { return [self getVisibleViewControllerFrom:vc.presentedViewController]; } else { return vc; }}}Copy the code

Runtime adds attributes to a class dynamically

// The essence of dynamically adding attributes is: Objc_setAssociatedObject (self, WZBPlaceholderViewKey, tagView, OBJC_ASSOCIATION_RETAIN_NONATOMIC);Copy the code

Get attributes that Runtime dynamically added to a class

objc_getAssociatedObject(self, WZBPlaceholderViewKey);

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64. KVO listens for properties of an object

/ / add listeners [self addObserver: self forKeyPath: property options: NSKeyValueObservingOptionNew context: nil]; - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary) *)change context:(void *)context { if ([keyPath isEqualToString:@"property"]) { [self textViewTextChange]; } else { } }Copy the code

65. Reachability Checks network status

NetworkStatus status = [[Reachability reachabilityForInternetConnection] currentReachabilityStatus]; If (status == NotReachable) {NSLog(@" Current device has no network "); } if (status == ReachableViaWiFi) {NSLog(@" current wifi network "); } if (status == ReachableViaWWAN) {NSLog(@" current cellular mobile network "); }Copy the code

AFNetworking Monitors network status

/ / to monitor network status AFNetworkReachabilityManager * MGR = [AFNetworkReachabilityManager sharedManager]; [mgr setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) { switch (status) { case AFNetworkReachabilityStatusUnknown: break; case AFNetworkReachabilityStatusNotReachable: {[SVProgressHUD showInfoWithStatus: @ "current equipment without network"];} break; case AFNetworkReachabilityStatusReachableViaWiFi: [SVProgressHUD showInfoWithStatus: @ "today's wi-fi network"]; break; case AFNetworkReachabilityStatusReachableViaWWAN: [SVProgressHUD showInfoWithStatus:@" current cellular network "]; break; default: break;}}]; [mgr startMonitoring];Copy the code

Transparent colors do not affect the transparency of subviews

    [UIColor colorWithRed:<#(CGFloat)#> green:<#(CGFloat)#> blue:<#(CGFloat)#> alpha:<#(CGFloat)#>];

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68, Pick a color at a point in the picture

if (point.x < 0 || point.y < 0) return nil; CGImageRef imageRef = self.CGImage; NSUInteger width = CGImageGetWidth(imageRef); NSUInteger height = CGImageGetHeight(imageRef); if (point.x >= width || point.y >= height) return nil; unsigned char *rawData = malloc(height * width * 4); if (! rawData) return nil; CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); NSUInteger bytesPerPixel = 4; NSUInteger bytesPerRow = bytesPerPixel * width; NSUInteger bitsPerComponent = 8; CGContextRef context = CGBitmapContextCreate(rawData, width, height, bitsPerComponent, bytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big); if (! context) { free(rawData); return nil; } CGColorSpaceRelease(colorSpace); CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef); CGContextRelease(context); int byteIndex = (bytesPerRow * point.y) + point.x * bytesPerPixel; CGFloat red = (rawData[byteIndex] * 1.0) / 255.0; CGFloat green = (rawData[byteIndex + 1] * 1.0) / 255.0; CGFloat blue = (rawData[byteIndex + 2] * 1.0) / 255.0; CGFloat alpha = (rawData[byteIndex + 3] * 1.0) / 255.0; UIColor *result = nil; result = [UIColor colorWithRed:red green:green blue:blue alpha:alpha]; free(rawData); return result;Copy the code

69. Determine whether the image has a transparency channel

  - (BOOL)hasAlphaChannel
{
    CGImageAlphaInfo alpha = CGImageGetAlphaInfo(self.CGImage);
    return (alpha == kCGImageAlphaFirst ||
            alpha == kCGImageAlphaLast ||
            alpha == kCGImageAlphaPremultipliedFirst ||
            alpha == kCGImageAlphaPremultipliedLast);
}

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70. Obtain grayscale images

+ (UIImage*)covertToGrayImageFromImage:(UIImage*)sourceImage { int width = sourceImage.size.width; int height = sourceImage.size.height; CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray(); CGContextRef context = CGBitmapContextCreate (nil, width, height, 8, 0, the colorSpace, kCGImageAlphaNone); CGColorSpaceRelease(colorSpace); if (context == NULL) { return nil; } CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage); CGImageRef contextRef = CGBitmapContextCreateImage(context); UIImage *grayImage = [UIImage imageWithCGImage:contextRef]; CGContextRelease(context); CGImageRelease(contextRef); return grayImage; }Copy the code

71. Read the image from the file name in the bundle

+ (UIImage *)imageWithFileName:(NSString *)name { NSString *extension = @"png"; NSArray *components = [name componentsSeparatedByString:@"."]; if ([components count] >= 2) { NSUInteger lastIndex = components.count - 1; extension = [components objectAtIndex:lastIndex]; name = [name substringToIndex:(name.length-(extension.length+1))]; } // If the screen is Retina and the corresponding image exists, return the Retina image, If ([UIScreen mainScreen].scale == 2.0) {name = [name stringByAppendingString:@"@2x"]; NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension]; if (path ! = nil) { return [UIImage imageWithContentsOfFile:path]; }} if ([UIScreen mainScreen].scale == 3.0) {name = [name stringByAppendingString:@"@3x"]; NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension]; if (path ! = nil) { return [UIImage imageWithContentsOfFile:path]; } } NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension]; if (path) { return [UIImage imageWithContentsOfFile:path]; } return nil; }Copy the code

72. Merge two images

+ (UIImage*)mergeImage:(UIImage*)firstImage withImage:(UIImage*)secondImage {
    CGImageRef firstImageRef = firstImage.CGImage;
    CGFloat firstWidth = CGImageGetWidth(firstImageRef);
    CGFloat firstHeight = CGImageGetHeight(firstImageRef);
    CGImageRef secondImageRef = secondImage.CGImage;
    CGFloat secondWidth = CGImageGetWidth(secondImageRef);
    CGFloat secondHeight = CGImageGetHeight(secondImageRef);
    CGSize mergedSize = CGSizeMake(MAX(firstWidth, secondWidth), MAX(firstHeight, secondHeight));
    UIGraphicsBeginImageContext(mergedSize);
    [firstImage drawInRect:CGRectMake(0, 0, firstWidth, firstHeight)];
    [secondImage drawInRect:CGRectMake(0, 0, secondWidth, secondHeight)];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

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Create an ImageView based on the name of the image in the bundle

+ (id)imageViewWithImageNamed:(NSString*)imageName
{
    return [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];
}

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Add a reflection to imageView

CGRect frame = self.frame; frame.origin.y += (frame.size.height + 1); UIImageView *reflectionImageView = [[UIImageView alloc] initWithFrame:frame]; self.clipsToBounds = TRUE; reflectionImageView.contentMode = self.contentMode; [reflectionImageView setImage:self.image]; ReflectionImageView. Transform = CGAffineTransformMakeScale (1.0, 1.0); CALayer *reflectionLayer = [reflectionImageView layer]; CAGradientLayer *gradientLayer = [CAGradientLayer layer]; gradientLayer.bounds = reflectionLayer.bounds; GradientLayer. Position = CGPointMake (reflectionLayer. Bounds. The size, width / 2, reflectionLayer. Bounds. Size, height * 0.5); gradientLayer.colors = [NSArray arrayWithObjects: (id)[[UIColor clearColor] CGColor], (id)[[UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.3] CGColor], nil]; GradientLayer. The startPoint = CGPointMake (0.5, 0.5); GradientLayer. The endPoint = CGPointMake (0.5, 1.0); reflectionLayer.mask = gradientLayer; [self.superview addSubview:reflectionImageView];Copy the code

Paint watermark

SetImage :(UIImage *)image withWaterMark:(UIImage *)mark inRect:(CGRect)rect {if ([[[UIDevice) CurrentDevice] floatValue systemVersion]] > = 4.0) {UIGraphicsBeginImageContextWithOptions (self. Frame. The size, NO, 0.0); } // Image drawInRect:self. Bounds]; [mark drawInRect:rect]; UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); self.image = newPic; }Copy the code

Make the text content of the label appear on the top left/top right/bottom left/bottom right/top center/bottom center

TextRectForBounds :(CGRect)bounds :(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines { CGRect rect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines]; switch (self.textAlignmentType) { case WZBTextAlignmentTypeLeftTop: { rect.origin = bounds.origin; } break; case WZBTextAlignmentTypeRightTop: { rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, bounds.origin.y); } break; case WZBTextAlignmentTypeLeftBottom: { rect.origin = CGPointMake(bounds.origin.x, CGRectGetMaxY(bounds) - rect.size.height); } break; case WZBTextAlignmentTypeRightBottom: { rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, CGRectGetMaxY(bounds) - rect.size.height); } break; case WZBTextAlignmentTypeTopCenter: { rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - rect.origin.y); } break; case WZBTextAlignmentTypeBottomCenter: { rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - CGRectGetMaxY(bounds) - rect.size.height); } break; case WZBTextAlignmentTypeLeft: { rect.origin = CGPointMake(0, rect.origin.y); } break; case WZBTextAlignmentTypeRight: { rect.origin = CGPointMake(rect.origin.x, 0); } break; case WZBTextAlignmentTypeCenter: { rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, (CGRectGetHeight(bounds) - CGRectGetHeight(rect)) / 2); } break; default: break; } return rect; } - (void)drawTextInRect:(CGRect)rect { CGRect textRect = [self textRectForBounds:rect limitedToNumberOfLines:self.numberOfLines]; [super drawTextInRect:textRect]; }Copy the code

77, scrollView input box, keyboard blocking problem

Recommend using IQKeyboardManager framework! NSDictionary* info = [aNotification userInfo]; CGRect keyPadFrame=[[UIApplication sharedApplication].keyWindow convertRect:[[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue] fromView:self.view]; CGSize kbSize =keyPadFrame.size; CGRect activeRect=[self.view convertRect:activeField.frame fromView:activeField.superview]; CGRect aRect = self.view.bounds; aRect.size.height -= (kbSize.height); CGPoint origin = activeRect.origin; origin.y -= backScrollView.contentOffset.y; if (! CGRectContainsPoint(aRect, Origin)) {CGPoint scrollPoint = CGPointMake(0.0,CGRectGetMaxY(activeRect)-(arect.sie.height)); [backScrollView setContentOffset:scrollPoint animated:YES]; }Copy the code

78. Dynamic height of the frame layout cell

This usually adds an auxiliary property cellHeight to your model, overrides the get method for that property in the model, and calculates the total height based on your layout and other property values in the model. Finally, in the tableView: heightForRow method, find the corresponding model according to indexPath, and return this height.

79, AutoLayout layout cell dynamic height

/ / 1 and set properties of the tableView self. TableView. RowHeight = UITableViewAutomaticDimension; The self. The tableView. EstimatedRowHeight = 44.0; // This attribute is non-zero. Estimate the cell heightCopy the code

// 2. Set the constraint of the cell from top to bottom. Note that the top, bottom, left and right should be all around the cellCopy the code

80, Using performSelector: call function, memory leak problem

When we use in development [obj performSelector: NSSelectorFromString (@ “aMethod”)]; This type of method may receive a warning “performSelector may cause a leak because its selector is unknown”. Because the compiler doesn’t know if the object corresponds to the method, and if it doesn’t, it’s unsafe, and the compiler doesn’t know what to do with the return value of the method!

Call it with the following code: if (! obj) { return; } SEL selector = NSSelectorFromString(@"aMethod"); IMP imp = [obj methodForSelector:selector]; void (*func)(id, SEL) = (void *)imp; func(obj, selector); Or SEL selector = NSSelectorFromString(@"aMethod"); ((void (*)(id, SEL))[obj methodForSelector:selector])(obj, selector);Copy the code

81. Whether a string contains another string

If ([str1 containsString:str2]) {NSLog(@"str1 contains str2"); } else {NSLog(@"str1 does not include str2"); If ([str1 rangeOfString: str2]. Location == NSNotFound) {NSLog(@"str1 does not include str2"); } else {NSLog(@"str1 contains str2"); }Copy the code

82. Remove the selected effect of cell

cell.selectionStyle = UITableViewCellSelectionStyleNone;

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83, Cell click effect

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
}

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From 84, when deleting a xib pulled properties, must remember the xib also delete the corresponding line, or you will quote similar [0 < ViewController x7fea6ed05980 > setValue: forUndefinedKey:] : This class is not key value coding-compliant for the key crash

Could not launch “your App”, process launch failed: Security

Because your app is not online, iOS9 starts, need to manually trust Xcode generated description file, open the phone Settings -> general -> description file -> click your app description file -> trust

86, Error: Could not find Developer Disk Image

This is because the OS version of your device is larger than the OS version that Xcode is compatible with. For example, if your device is iOS10.3 and Xcode is 8.2 (Xcode8.2 is most compatible with iOS10.2), this error will be reported. The solution is to upgrade Xcode!

UITextView not placeholder problem?

There are many such custom controls on the web. You can also refer to the UITextView category I wrote uitextView-wzb

88. Remove whitespace and newlines from strings

+ (NSString *)removeSpaceAndNewline:(NSString *)str {
    NSString *temp = [str stringByReplacingOccurrencesOfString:@" " withString:@""];
    temp = [temp stringByReplacingOccurrencesOfString:@"\r" withString:@""];
    temp = [temp stringByReplacingOccurrencesOfString:@"\n" withString:@""];
    return temp;
}

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89, Check whether the string contains Spaces

+ (BOOL)isBlank:(NSString *)str { NSRange _range = [str rangeOfString:@" "]; if (_range.location ! NSNotFound) {// return YES; } else {// NO space return NO; }}Copy the code

Get the first frame of a video

    NSURL *url = [NSURL URLWithString:filepath];
    AVURLAsset *asset1 = [[AVURLAsset alloc] initWithURL:url options:nil];
    AVAssetImageGenerator *generate1 = [[AVAssetImageGenerator alloc] initWithAsset:asset1];
    generate1.appliesPreferredTrackTransform = YES;
    NSError *err = NULL;
    CMTime time = CMTimeMake(1, 2);
    CGImageRef oneRef = [generate1 copyCGImageAtTime:time actualTime:NULL error:&err];
    UIImage *one = [[UIImage alloc] initWithCGImage:oneRef];

    return one;

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91. Get the duration of the video

+ (NSInteger)getVideoTimeByUrlString:(NSString *)urlString {
    NSURL *videoUrl = [NSURL URLWithString:urlString];
    AVURLAsset *avUrl = [AVURLAsset assetWithURL:videoUrl];
    CMTime time = [avUrl duration];
    int seconds = ceil(time.value/time.timescale);
    return seconds;
}

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92. Whether the string is empty

+ (BOOL)isEqualToNil:(NSString *)str { return str.length <= 0 || [str isEqualToString:@""] || ! str; }Copy the code

93. This is a common problem when uploading an app to the App Store

A lot of people say this is apple dad server problem, repeat a few times, always successful! However, after trying to find that the upload success rate is very high if you use Application Loader, so it is still recommended to export the IPA file and upload it directly using Application Loader. If the Application Loader fails, you need to check your network. Sometimes VPN can improve the speed.

94, When the tableView occupies less than a screen, remove the extra cells below

self.tableView.tableHeaderView = [UIView new];
self.tableView.tableFooterView = [UIView new];

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95, isKindOfClass and isMemberOfClass difference

IsKindOfClass determines whether an object belongs to a class or a subclass of that class. IsMemberOfClass is more precise, it can only determine if the object type is the class (not the subclass)Copy the code

96, __block

When a local variable to change in the block, the need to define plus __block when decorate, specific look at the official documentation developer.apple.com/library/ios…

97, -[ViewController aMethod:]: Unrecognized selector sent to instance 0x7fe91e607fB0

This is a classic error. The ViewController cannot respond to the aMethod method. The reason may be that the aMethod method is not implemented in the ViewController file

98, UITableView (<UITableView: 0x7ff19b027000; >) failed to obtain a cell from its dataSource (<ViewController: 0x7ff19a507520>)

This is the reason for the error tableView proxy method – tableView: cellForRowAtIndexPath: need to return a UITableViewCell, and you return a nil. The other thing is that this place that doesn’t return a value of type UITableViewCell will crash as well

Constraint how to animate UIView?

2. Add code where you need to animate the constant property of this property. 3. @property (weak, nonatomic) IBOutlet NSLayoutConstraint *buttonTopConstraint; self.buttonTopConstraint.constant = 100; [UIView animateWithDuration:.5 animations:^{ [self.view layoutIfNeeded]; }];Copy the code

Get the link string from NSURL

NSString *urlString = myURL.absoluteString;

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Scroll the tableView to the top

[tableView setContentOffset:CGPointZero animated:YES]; Or [tableView scrollRectToVisible: CGRectMake (0, 0, 1, 1) animated: YES];Copy the code

102, if use addTarget: action: forControlEvents: methods to click a button to add a lot of events, at some point to a deleted? All you need to do is call the following line

[youButton removeTarget:nil action:nil forControlEvents:UIControlEventAllEvents];

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103, The height of a font

font.lineHeight;

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Delete all subviews of a view

[[someView subviews]
 makeObjectsPerformSelector:@selector(removeFromSuperview)];

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105, Delete all NSUserDefaults records

// NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier]; [[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain]; Void setDefaults {NSUserDefaults * defs = [NSUserDefaults * defs]; NSDictionary * dict = [defs dictionaryRepresentation]; for (id key in dict) { [defs removeObjectForKey:key]; } [defs synchronize]; [NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[NSBundle mainBundle] bundleIdentifier]];Copy the code

106. Disable the system slide back function

- (void)viewDidAppear:(BOOL)animated
{
     [super viewDidAppear:animated];
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = self;
    }
}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = nil;
    }
}
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
     return NO;
}

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107. The simulator reported an error

Open the Simulator-> Simulator->Reset Content and Settings… If not, reboot!

108. Customize cell Select the background color

UIView *bgColorView = [[UIView alloc] init];
bgColorView.backgroundColor = [UIColor redColor];
[cell setSelectedBackgroundView:bgColorView];

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109. UILabel sets the inner margin

UIEdgeInsets = {0, 5, 0, 5}; void drawTextInRect (void drawTextInRect) {UIEdgeInsets = {0, 5, 0, 5}; [super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)]; }Copy the code

UILabel sets text stroke

Subclass UILabel, rewrite drawTextInRect method - (void) drawTextInRect: (CGRect) the rect {CGContextRef c = UIGraphicsGetCurrentContext (); CGContextSetLineWidth(c, 1); CGContextSetLineJoin(c, kCGLineJoinRound); CGContextSetTextDrawingMode(c, kCGTextStroke); Self. textColor = [UIColor redColor]; [super drawTextInRect:rect]; Self. textColor = [UIColor yellowColor]; CGContextSetTextDrawingMode(c, kCGTextFill); [super drawTextInRect:rect]; }Copy the code

111. Screenshot using simulator

Shortcut command + S or File->Save Screen Shot

112, scrollView scroll to the bottom

CGPoint bottomOffset = CGPointMake(0, scrollView.contentSize.height - scrollView.bounds.size.height);
[scrollView setContentOffset:bottomOffset animated:YES];

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UIView background color gradient

    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)];
    [self.view addSubview:view];
    CAGradientLayer *gradient = [CAGradientLayer layer];
    gradient.frame = view.bounds;
    gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil];
    [view.layer insertSublayer:gradient atIndex:0];

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114, Stop UIView animation

[yourView.layer removeAllAnimations]

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115. Add a rounded corner to a corner of UIView

/ / the top left corner and the bottom right hand corner to add rounded corners UIBezierPath * maskPath = [UIBezierPath bezierPathWithRoundedRect: the bounds byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerBottomRight) cornerRadii:CGSizeMake(20, 20)]; CAShapeLayer *maskLayer = [CAShapeLayer layer]; maskLayer.frame = view.bounds; maskLayer.path = maskPath.CGPath; view.layer.mask = maskLayer;Copy the code

116, Delete Xcode Derived Data cache data

Click Xcode -> Preferences -> Location, and then click the Derived Data path to go to the little arrow and delete the data under that folder, as shown

Place a view at the top of its sibling view

[parentView bringSubviewToFront:yourView]

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Place a view at the bottom of its sibling view

[parentView sendSubviewToBack:yourView]

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Let the phone vibrate

Add in frame # import < AudioToolbox/AudioToolbox. H > AudioServicesPlayAlertSound (kSystemSoundID_Vibrate); Or AudioServicesPlaySystemSound (kSystemSoundID_Vibrate);Copy the code

120, When is the layoutSubviews method called?

The addSubview method is called when the bounds change The layoutSubviews method of scrollView will be called when the scrollView is rolled (so it is not recommended to do complex logic in the layoutSubviews method of scrollView) Blog.logichigh.com/2011/03/16/…

121, Line wrap UILabel in the specified place

// The newline character is \n, which can be added to places where newlines are needed, for example, label.numberoflines = 0; Label. text = @" here \n newline ";Copy the code

122. Shake the function

1, open the shake function [UIApplication sharedApplication]. ApplicationSupportsShakeToEdit = YES; 2, let the controller that needs to be shaken become the first responder [self becomeFirstResponder]; // start shaking - (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event // end of motion - (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)eventCopy the code

123. Get the image size

CGFloat imageWidth = image.size.width;
    CGFloat imageHeight = imageWidth * image.scale;

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Get the view coordinate position on the entire window

CGPoint point = [v convertPoint:CGPointMake(0, 0) 0) toView:[UIApplication sharedApplication].windows.lastObject]; Or CGPoint point = [v. uperview convertPoint: v. rame. Origin toView: [UIApplication sharedApplication].windows.lastObject];Copy the code

125. Restrictions on submission to App Store review procedures

The uncompressed size of your application must be less than 4GB. Each Mach-O executable (e.g. App_name.app /app_name) cannot exceed these limits: for applications where MinimumOSVersion is less than 7.0: __TEXT The total number of all parts in the binary is at most 80 MB.

For Minimumosversion7.x to 8.x applications: __TEXT Maximum 60 MB for each fragment of each architectural fragment in the binary. For MinimumOSVersion9.0 or later applications: the total number of all parts in the __TEXT binary is at most 500 MB. See also: iTunes Connect Developer’s Guide

126, Change the font size of UISegmentedControl

[segment setTitleTextAttributes: @ {NSFontAttributeName: [UIFont systemFontOfSize: 15.0 f]} forState: UIControlStateNormal];Copy the code

The UIAlertController dialog box is displayed where the ViewController is not

/ / the best smoke into a classification UIAlertController * alertController = [UIAlertController alertControllerWithTitle: @ "Title" message: @ "message"  preferredStyle:UIAlertControllerStyleAlert]; / /... id rootViewController = [UIApplication sharedApplication].delegate.window.rootViewController; if([rootViewController isKindOfClass:[UINavigationController class]]) { rootViewController = ((UINavigationController *)rootViewController).viewControllers.firstObject; } if([rootViewController isKindOfClass:[UITabBarController class]]) { rootViewController = ((UITabBarController *)rootViewController).selectedViewController; } [rootViewController presentViewController:alertController animated:YES completion:nil];Copy the code

Get a view controller

BelongViewController {for (UIView *next = [self superview]; next; next = next.superview) { UIResponder* nextResponder = [next nextResponder]; if ([nextResponder isKindOfClass:[UIViewController class]]) { return (UIViewController *)nextResponder; } } return nil; }Copy the code

UIImage and base64 interswitch

- (NSString *)encodeToBase64String:(UIImage *)image {return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength]; } - (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData { NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters]; return [UIImage imageWithData:data]; }Copy the code

UIWebView set background transparency

[webView setBackgroundColor:[UIColor clearColor]];
[webView setOpaque:NO];

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NSDate is today

NSDateComponents *otherDay = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:aDate]; NSDateComponents *today = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:[NSDate date]]; if([today day] == [otherDay day] && [today month] == [otherDay month] && [today year] == [otherDay year] && [today era] == [otherDay era]) {// is today}Copy the code

132, Set the color of tableView divider

[self.tableView setSeparatorColor:[UIColor myColor]];

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133. Set screen orientation

 NSNumber *orientationTarget = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeLeft];
[[UIDevice currentDevice] setValue:orientationTarget forKey:@"orientation"];
[UIViewController attemptRotationToDeviceOrientation];

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Compare the two colors for equality

- (BOOL)isEqualToColor:(UIColor *)otherColor {
    CGColorSpaceRef colorSpaceRGB = CGColorSpaceCreateDeviceRGB();

    UIColor *(^convertColorToRGBSpace)(UIColor*) = ^(UIColor *color) {
        if (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) == kCGColorSpaceModelMonochrome) {
            const CGFloat *oldComponents = CGColorGetComponents(color.CGColor);
            CGFloat components[4] = {oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]};
            CGColorRef colorRef = CGColorCreate( colorSpaceRGB, components );

            UIColor *color = [UIColor colorWithCGColor:colorRef];
            CGColorRelease(colorRef);
            return color;            
        } else
            return color;
    };

    UIColor *selfColor = convertColorToRGBSpace(self);
    otherColor = convertColorToRGBSpace(otherColor);
    CGColorSpaceRelease(colorSpaceRGB);

    return [selfColor isEqual:otherColor];
}

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135, tableViewCell splitter line top to end

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
    [cell setSeparatorInset:UIEdgeInsetsZero];
    [cell setLayoutMargins:UIEdgeInsetsZero];
    cell.preservesSuperviewLayoutMargins = NO;
}

- (void)viewDidLayoutSubviews {
    [self.tableView setSeparatorInset:UIEdgeInsetsZero];
    [self.tableView setLayoutMargins:UIEdgeInsetsZero];
}

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Don’t let the controller’s view stretch or compress with the controller’s XIB

self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

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CocoaPods error: [!] Unable to add a source with urlhttps://github.com/CocoaPods/Specs.git named master-1.

You can try adding it manually in ~/.cocoapods/repos or via pod repo add.

Sudo xcode-select-switch /Applications/ xcode.app is used by cocoapods because another Xcode is installed on the PC

ERROR: While Executing Gem… (Errno::EPERM)

Operation not permitted - /usr/bin/pod

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Solution: Directly run sudo gem install -n /usr/local/bin cocoapods on the terminal

139. Add a web request chrysanthemum to the status bar, similar to how Safari loads web pages

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

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140, Check if a recT contains a point

BOOL isContains = CGRectContainsPoint(rect, point);Copy the code

141, Let UILabel automatically set the best font for the specified width

label.adjustsFontSizeToFitWidth = YES;

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142. Save an image in an album

UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil); Or #import <Photos/ photos.h > [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{PHAssetChangeRequest *changeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image]; changeRequest.creationDate = [NSDate date]; } completionHandler:^(BOOL success, NSError *error) { if (success) { NSLog(@"successfully saved"); } else { NSLog(@"error saving to photos: %@", error); } }];Copy the code

143, Change the size of cell.imageView

UIImage *icon = [UIImage imageNamed:@""]; CGSize itemSize = CGSizeMake(30, 30); UIGraphicsBeginImageContextWithOptions (itemSize, NO, 0.0); CGRect imageRect = CGRectMake(0.0, 0.0, itemsize.width, itemsize.height); [icon drawInRect:imageRect]; cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();Copy the code

144. Add a dotted border to a view

CAShapeLayer *border = [CAShapeLayer layer]; Border-.strokecolor = [UIColor colorWithRed:67/255.0f green:37/255.0f blue:83/255.0f alpha:1].cgcolor; border.fillColor = nil; border.lineDashPattern = @[@4, @2]; border.path = [UIBezierPath bezierPathWithRect:view.bounds].CGPath; border.frame = view.bounds; [view.layer addSublayer:border];Copy the code

145, UITextView enable or disable copy, cut, select, select all functions

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender { If (action == @selector(paste:)) return NO; If (action == @selector(cut:)) return NO; If (action == @selector(copy:)) return NO; // select if (action == @selector(select:)) return NO; // selectAll if (action == @selector(selectAll:) return NO; If (action == @selector(delete:)) return NO; If (action == @selector(share)) return NO; return [super canPerformAction:action withSender:sender]; }Copy the code