Singleton mode for ios

The Singleton mode only has one instance. Instantiate the instance and provide the instance to the entire system.

Create Singleton Mode 1. First, in the. h file

#import <Foundation/Foundation.h>@interface SingletonClass : NSObject+ (id) sharedInstance;@end

2. In the. m file

#import "SingletonClass.h"@implementation SingletonClassstatic SingletonClass * getInstance;+ (id) sharedInstance {    @synchronized ([SingletonClass class]) {        if (getInstance == nil) {            getInstance = [[SingletonClass alloc] init];        }    }    return getInstance;}@end

Here is an example of SingletonClass. Singleton Mode

[[SingletonClass sharedInstance] xxx];

The destruction and destruction of a singleton is the release of the singleton. The delegate method is as follows when the application is terminated.

- (void)applicationWillTerminate:(UIApplication *)application{    [SingletonClass destroyDealloc];}

Destruction Method

+ (void)destroyDealloc{    if ([getInstance retainCount] != 1)        return;        [getInstance release];    getInstance = nil;}

Summary of the benefits of Singleton: 1. instance control: Singleton will prevent other objects from instantiating copies of their own Singleton objects, so that all objects can access a unique instance.
2. Flexibility: Because the class controls the instantiation process, the class can be more flexible to modify the instantiation process. Disadvantages: The Singleton mode makes the object global, reducing the flexibility of each module.