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 --> btnStartClickedthen 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;
}
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