Multi-view application

Most iOS applications are designed with multiple views.

4 kinds of multi-view programs of controller type: 1. Custom view controller; (UIViewController) 2. (UITabBarController) (UINavigationController) 4. (UITableViewController)

View and controller class diagram:

UIVisualEffectView

Officer: developer.apple.com/documentati…

Usually to implement a special effect, such as a blur effect, you can create a “UIVisualEffectView” view object, which provides a simple way to achieve complex visual effects. You can think of this object as a container for effects that affect what’s underneath the view object, or what’s added to the view object’s contentView.

Example 🌰 Reference:

Add special effects to the view with UIVisualEffectView iOS8 Blur effect use UIVisualEffectView

(2017.11.19)

Reference counting

Definition: Reference Count, also called retain Count, represents the number of times an object is referenced.

Purpose: Reference counting is used to manage memory. Each object has a counter that indicates how many objects (things) currently want this object to live.

Relation to memory management?

In objective-C memory management, each object has its own counter:

If you want to keep an object alive (for example, if you want to reference it), increment its reference count; When it is finished, it decrements its reference count; When no one references the object and its count goes to zero, the system destroys it.

Working principle:

Reference:

Objective-c memory management iOS development — ARC and reference counting

(2017.11.01)

App Extension

Official description: developer.apple.com/app-extensi… App extensions give users access to your App’s functionality and content throughout iOS and macOS.

It involves everything from panels of the Day, keyboards, content blockers, sharing actions, etc.

App Extension Programming Guide (iOS8/OS X V10.10

Share Extension in the App Extensions section ⭐️

Inside iOS App Extension Development — Today’s App Extensions article on Messenger Pack Extension

(2017.09.08)

ASO (Short for App Store Optimization)

ASO is short for “App Store optimization.” It is the process of improving your APP’s ranking in various APP market charts and search results. Use the App Store’s search rules and ranking rules to make your App easier to search or see.

Similar to ordinary websites for Search Engine Optimization, that is, SEO (Search Engine Optimization) Optimization.

Key points: keyword search ranking optimization.

For more information, see: What are the ways to operate ASO on the App Store?

Keychain: Keychain

IOS simply uses keychain to store passwords

KeyChain is used to save user passwords in iOS development

(2017.08.05)

msync(): Refresh the change function

Changes to shared content made by a process in mapped space are not written directly back to the disk file, usually after munmap() is called. You can use the msync() function to “match the contents of the disk file to the contents of the shared memory area,” that is, the synchronization operation.

Function prototype:

 int msync ( void * addr, size_t len, int flags)
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The header file:

 #include<sys/mman.h>
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parameter

  • Addr: address of the file mapped to the process space;
  • Len: size of mapping space;
  • Flags: refreshing parameter Settings. The values can be MS_ASYNC, MS_SYNC, or MS_INVALIDATE.

Return value: 0 on success; On failure, -1 is returned.

Daily summary……

(2017.11.07)

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