在iOS中对后台线程执行任务，即使应用程序进入后台也能继续执行：

本文介绍了在iOS中对后台线程执行任务，即使应用程序进入后台也能继续执行：的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

如何在后台线程上执行？即使用户按下主页按钮，执行也应在后台继续。

How to perform execution on a background thread? Execution should continue in the background even if the user presses the home button.

推荐答案

将这些属性添加到.h文件中

Add these properties to your .h file

@property (nonatomic, strong) NSTimer *updateTimer; @property (nonatomic) UIBackgroundTaskIdentifier backgroundTask;

现在假设您对按钮有一个操作 - > btnStartClicked 那么您的方法将是喜欢：

Now suppose you have a action on button --> btnStartClicked then your method would be like :

-(IBAction)btnStartClicked:(UIButton *)sender { self.updateTimer = [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(calculateNextNumber) userInfo:nil repeats:YES]; self.backgroundTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{ NSLog(@"Background handler called. Not running background tasks anymore."); [[UIApplication sharedApplication] endBackgroundTask:self.backgroundTask]; self.backgroundTask = UIBackgroundTaskInvalid; }]; } -(void)calculateNextNumber{ @autoreleasepool { // this will be executed no matter app is in foreground or background } }

如果你需要停止使用这种方法，

and if you need to stop it use this method,

- (IBAction)btnStopClicked:(UIButton *)sender { [self.updateTimer invalidate]; self.updateTimer = nil; if (self.backgroundTask != UIBackgroundTaskInvalid) { [[UIApplication sharedApplication] endBackgroundTask:self.backgroundTask]; self.backgroundTask = UIBackgroundTaskInvalid; } i = 0; }