通常在使用NSTimer时是如下：
这样self强引用timer，timer强引用self，会造成self和timer循环引用，self和timer都销毁不了。
//需要主动开启timer
NSTimer *timer = [NSTimer timerWithTimeInterval:1.0 target:self
selector:@selector(loopTimer:) userInfo:nil repeats:YES];
self.timer = timer;
NSRunLoop *runLoop = [NSRunLoop currentRunLoop];
[runLoop addTimer:timer forMode:NSRunLoopCommonModes];
[runLoop run];
//自动开启timer
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self
selector:@selector(loopTimer:) userInfo:nil repeats:YES];
self.timer = timer;
//定时器回调
- (void)loopTimer:(NSTimer *)timer{
//执行任务
}
解决方案：使用isLoop变量记录状态，在需要销毁定时器的时候把isLoop赋值为NO。
//需要主动开启timer
NSTimer *timer = [NSTimer timerWithTimeInterval:1.0 target:self
selector:@selector(loopTimer:) userInfo:nil repeats:YES];
NSRunLoop *runLoop = [NSRunLoop currentRunLoop];
[runLoop addTimer:timer forMode:NSRunLoopCommonModes];
[runLoop run];
self.isLoop = YES;
//自动开启timer
[NSTimer scheduledTimerWithTimeInterval:1.0 target:self
selector:@selector(loopTimer:) userInfo:nil repeats:YES];
self.isLoop = YES;
//定时器回调
- (void)loopTimer:(NSTimer *)timer{
if(self.isLoop = YES){
//执行任务
}else{
//停止timer 并销毁
[timer invalidate];
timer = nil;
}
}
