項目中要用到動畫的控制，比如說暫停、恢復繼續等，先看代碼：（很容易實現）

-(void)pauseLayer:(CALayer*)layer
{
    CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
    layer.speed = 0.0;
    layer.timeOffset = pausedTime;
}

-(void)resumeLayer:(CALayer*)layer
{
    CFTimeInterval pausedTime = [layer timeOffset];
    layer.speed = 1.0;
    layer.timeOffset = 0.0;
    layer.beginTime = 0.0;
    CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
    layer.beginTime = timeSincePause;
}

如果在一個view中我們添加了多個動畫，（不是組合動畫），同樣容易實現動畫的暫停、恢復，方法就是為每個動畫層layer調用上面的方法，比如我的方法如下，我用的是三個單獨動畫的組合效果，就是如下調用的

-(void)stopAnimation;
{
    NSLog(@"停止動畫");
    //[_customView.layer removeAllAnimations];
    [self pauseLayer:_customView1.layer];
    [self pauseLayer:_customView2.layer];
    [self pauseLayer:_customView3.layer];
}

-(void)resumeAnimation
{
    [self resumeLayer:_customView1.layer];
    [self resumeLayer:_customView2.layer];
    [self resumeLayer:_customView3.layer];

}