5.iOS 自定义后台

#import <UIKit/UIKit.h>@interface MyAppDelegate : UIResponder <UIApplicationDelegate>{    int count;    UIBackgroundTaskIdentifier taskID;}@property (strong, nonatomic) UIWindow *window;@end

#import "MyAppDelegate.h"@implementation MyAppDelegate- (void)dealloc{    [_window release];    [super dealloc];}- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];    // Override point for customization after application launch.    self.window.backgroundColor = [UIColor whiteColor];    [self.window makeKeyAndVisible];    //    [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(timeAction:) userInfo:nil repeats:YES];    return YES;}//-(void)timeAction:(NSTimer*)timer//{//    count++;//    NSLog(@"%d",count);//}-(void)TimesrAction:(NSTimer*)timer{    count++;    if (count==500) {        UIApplication *application=[UIApplication sharedApplication];        [application endBackgroundTask:taskID];                //开启一个新的后台        taskID=[application beginBackgroundTaskWithExpirationHandler:^{                    }];    }    NSLog(@"%d",count);}//后台服务时，监听- (void)applicationDidEnterBackground:(UIApplication *)application{//    //开启一个后台任务,默认600秒//    taskID=[application beginBackgroundTaskWithExpirationHandler:^{//        //结束指定的任务//        [application endBackgroundTask:taskID];//    }];            taskID=[application beginBackgroundTaskWithExpirationHandler:^{        [application endBackgroundTask:taskID];    }];        [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(TimesrAction:) userInfo:nil repeats:YES];}