Question

我在类中使用此方法来启动操作：

[self performSelector:@selector(startRolling) withObject:nil afterDelay:0.1f];

为了阻止它，我正在使用：

[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(startRolling) object:nil];

但永远不会停止。

两个调用都在同一个类和同一个线程中实现。

我也使用过它，但它没有解决它：

-(void)stopRolling
{
    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(startRolling) object:nil];
    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(commitAnimation) object:nil];

    [NSObject cancelPreviousPerformRequestsWithTarget:self];
    [[NSRunLoop currentRunLoop] cancelPerformSelectorsWithTarget:self];
}

我缺少什么？

感谢。

--- --- EDIT

要知道我正在使用的是主线程：

-(void)stopRolling
{
    if ([NSThread isMainThread])
        NSLog(@"Is Main Thread");

    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(startRolling) object:nil];
    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(commitAnimation) object:nil];

    [NSObject cancelPreviousPerformRequestsWithTarget:self];
    [[NSRunLoop currentRunLoop] cancelPerformSelectorsWithTarget:self];
}

当工作正常并且在日志中并不总是出现时是主线程。

我正在启动的选择器（startRolling和commitAnimations）是使用[UIView beginAnimation：context :)的动画

这可能是原因吗？

这里的方法：

-(void)startRolling
{
    currentPic++;

    if (currentPic > count)
        currentPic = 1;

    [UIView beginAnimations:@"fadeIn" context:nil];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDuration:RDFadeInDelay];

    NSLog(@"RollUp: %@",[NSString stringWithFormat:@"RDInitialRollUp_%d",currentPic]);

    background.image = [UIImage imageNamed:[NSString stringWithFormat:@"RDInitialRollUp_%d.jpg",currentPic]];

    background.alpha = 1.0f;    

    [UIView commitAnimations];

}
- (void)animationDidStop:(NSString *)animationID finished:(NSNumber *) finished context:(void *) context
{
    if ([animationID isEqualToString:@"fadeIn"])
    {
        [self performSelector:@selector(commitAnimation) withObject:nil afterDelay:RDOnScreenDelay];
    }
    else
    {
        [self performSelector:@selector(startRolling) withObject:nil afterDelay:0.1f];

    }
}
-(void)commitAnimation
{
    [UIView beginAnimations:@"fadeOut" context:nil];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDuration:RDFadeOutDelay];

    background.alpha = 0.0f;    

    [UIView commitAnimations];
}
-(void)stopRolling
{
    if ([NSThread isMainThread])
        NSLog(@"Is Main Thread");

    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(startRolling) object:nil];
    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(commitAnimation) object:nil];

    [NSObject cancelPreviousPerformRequestsWithTarget:self];
    [[NSRunLoop currentRunLoop] cancelPerformSelectorsWithTarget:self];
}

使用performOnMainThread调用调用stopRolling方法的方法：

感谢。

- EDIT ---

我已经使用建议修改了方法，但仍无效：

-(void)stopRolling
{
    if ([NSThread isMainThread])
        NSLog(@"Is Main Thread");
    else
        NSLog(@"Is NOT Main Thread");

    [self.layer removeAllAnimations];

    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(startRolling) object:nil];
    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(commitAnimation) object:nil];

    [NSObject cancelPreviousPerformRequestsWithTarget:self];
    [[NSRunLoop currentRunLoop] cancelPerformSelectorsWithTarget:self];
}

我观察过，如果用户在执行图像之间的转换时点击屏幕，则表示不起作用。但是，如果用户在屏幕上显示图像时屏幕上（2秒内），则一切正常。

始终在主线上。

:(我很失败，这会导致程序崩溃，因为内存。

- 编辑 -

最后我解决了使用BOOL标志的问题。但我认为这是一个糟糕的解决方案，因为这必须没有。正在执行动画时会发生奇怪的事情，因为这仅在动画未执行时才有效。

这适用于所有情况：

- (void)animationDidStop:(NSString *)animationID finished:(NSNumber *) finished context:(void *) context
{
    if (!mustAnimate) return;

    if ([animationID isEqualToString:@"fadeIn"])
    {
        [self performSelector:@selector(commitAnimation) withObject:nil afterDelay:RDOnScreenDelay];
    }
    else
    {
        [self performSelector:@selector(startRolling) withObject:nil afterDelay:0.1f];

    }
}
-(void)commitAnimation
{
    [UIView beginAnimations:@"fadeOut" context:nil];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDuration:RDFadeOutDelay];

    background.alpha = 0.0f;    

    [UIView commitAnimations];
}
-(void)stopRolling
{
    mustAnimate = NO;

    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(startRolling) object:nil];
    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(commitAnimation) object:nil];

}

感谢您的一切。

Answer 1

更改传递给两个方法的参数，如图所示，

[self performSelector:@selector(SampleMethod) withObject:self afterDelay:delayTime];     
[NSObject cancelPreviousPerformRequestsWithTarget:self];

cancelPreviousPerformRequestsWithTarget不起作用

1 个答案: