PK creative Spring Festival, I am participating in the “Spring Festival creative submission contest”, please see: Spring Festival creative submission Contest
The cause of
The annual Spring Festival is coming. All major manufacturers’ apps have changed the Icon into the Spring Festival picture. It is strange that the Logo will change if the APP is not updated. Today, let’s talk about this technology point (Taobao, Alipay has been used for several years).
demand
- Modify Icon in App
- The silent switch
System apis
First, this technology is only available on iOS 10.3 and above
Let’s show you the system API
Available (iOS 10.3, *) open var supportsAlternateIcons: Bool {get}// Whether the standby logo is supported // Pass 'nil' to use the primary application icon. The Completion handler will be invoked asynchronously on an arbitrary background queue; Be sure to dispatch back to the main queue before doing any further UI work. @available(iOS 10.3, *) open func setAlternateIconName(_ alternateIconName: String? , completionHandler: ((Error?) -> Void)? // If 'nil', the primary application icon is being used. @available(iOS 10.3, *) open var alternateIconName: String? {get}// Name of the current logoCopy the codeThe Internet found the way to achieve
Online checked the next information, first said the implementation steps on the Internet:
1. Add icon images
The image is placed in the project directory, not in the system’s resource management Assets file
2. Info.plist configuration
Add keywords to info.plist: Icon Files (iOS 5)
There seems to be no CFBundleAlternateIcons keyword on the Internet
No, then add it manually, according to the appearance of the post added
It can be seen that the item above corresponds to the name of icon. Multiple items can be added here for adaptation of various devices
3. Call code
In the code
if UIApplication.shared.supportsAlternateIcons{ let str = UIApplication.shared.alternateIconName if str ! = "sunshine"{ UIApplication.shared.setAlternateIconName("sunshine") { error in if error ! = nil{ print("\(String(describing: error))") } } } }Copy the codeNote: Sunshine corresponds to the name configured above
4. Summary of online information implementation
In addition, resource management is placed under the project directory. As apple is known for its elegance, it will tolerate such problems. In the spirit of exploration, it has taken a look at the project configuration
A more elegant implementation
Alternate App Icon Sets under Build Settings, Alternate App Icon Sets
1. Now create two AppIcon resource folders under the project resource folder, named sat and GUA respectively, and add resources according to the way of configuring common logo
2. Double-click on the right of the Alternate App Icon Sets item under Build Settings to add sat GUA
3. Use the setup code above
OK, that’s it. Very simple there is no ！！！！
Popover problem handling
However, you must have found some problems when using it. In this way, there will be a prompt pop-up window, which is not as elegant as Taobao and Alipay. With the attitude of pursuing perfection, we continued to study and found that the pop-up window is UIAlertController without title and message
This is where the magic comes in, Runtime
Swift language popover processing code
Direct code :Swift
extension UIViewController{ public class func initializeMethod(){ if self ! = UIViewController.self{ return } DispatchQueue.once(token: "ChangeIcon") { let orignal = class_getInstanceMethod(self, #selector(UIViewController.present(_:animated:completion:))) let swizzling = class_getInstanceMethod(self, #selector(UIViewController.ssl_present(_:animated:completion:))) if let old = orignal, let new = swizzling{ method_exchangeImplementations(old, new) } } } @objc private func ssl_present(_ viewControllerToPresent: UIViewController, animated flag: Bool, completion: (() -> Void)? = nil) { if viewControllerToPresent is UIAlertController{ let vc = viewControllerToPresent as! UIAlertController if vc.title == nil && vc.message == nil{ return } } self.ssl_present(viewControllerToPresent, animated: flag, completion: completion) } } extension DispatchQueue{ private static var _onceTracker = [String]() public class func once(token: String, block:()->()){ objc_sync_enter(self) defer{ objc_sync_exit(self) } if _onceTracker.contains(token){ return } _onceTracker.append(token) block() } }Copy the codeEnable:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
UIViewController.initializeMethod()
return true
}
Copy the codeOC language popover processing code
Don’t forget old friends, find ObjectC code reference address online
// UIViewController+LQNoPresent.h
#import <UIKit/UIKit.h>
@interface UIViewController (LQNoPresent)
@end
#import "UIViewController+LQNoPresent.h"
#import <objc/runtime.h>
@implementation UIViewController (LQNoPresent)
+ (void)load {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Method presentM = class_getInstanceMethod(self.class, @selector(presentViewController:animated:completion:));
Method presentSwizzlingM = class_getInstanceMethod(self.class, @selector(lq_presentViewController:animated:completion:));
method_exchangeImplementations(presentM, presentSwizzlingM);
});
}
- (void)lq_presentViewController:(UIViewController *)viewControllerToPresent animated:(BOOL)flag completion:(void (^)(void))completion {
if ([viewControllerToPresent isKindOfClass:[UIAlertController class]]) {
// NSLog(@"title : %@",((UIAlertController *)viewControllerToPresent).title);
// NSLog(@"message : %@",((UIAlertController *)viewControllerToPresent).message);
UIAlertController *alertController = (UIAlertController *)viewControllerToPresent;
if (alertController.title == nil && alertController.message == nil) {
return;
}
}
[self lq_presentViewController:viewControllerToPresent animated:flag completion:completion];
}
@end
Copy the codeHere is the end, the perfect end of the demand, if there is any deficiency, welcome to correct!!
Record the whole process of iOS dynamic Icon replacement