UImagview实现渐变隐藏

实现UImagview渐变然后隐藏。

代码：

   CABasicAnimation *theAnimation;
   theAnimation=[CABasicAnimation animationWithKeyPath:@"opacity"];
   theAnimation.duration=1.0;
   theAnimation.fromValue=[NSNumber numberWithFloat:1.0];
   theAnimation.toValue=[NSNumber numberWithFloat:0.0];
   [flowerImageView.layer addAnimation:theAnimation forKey:@"animateOpacity"];

没实现等到值成为0.0时，imageView就完全隐藏起来。

没有回掉方法，用一个NSTimer

 CABasicAnimation *theAnimation;
 theAnimation=[CABasicAnimation animationWithKeyPath:@"opacity"];
 theAnimation.duration=1.0;
 theAnimation.fromValue=[NSNumber numberWithFloat:1.0];
 theAnimation.toValue=[NSNumber numberWithFloat:0.0];
 [flowerImageView.layer addAnimation:theAnimation forKey:@"animateOpacity"];

 [NSTimer scheduledTimerWithTimeInterval:theAnimation.duration
    target:self
    selector:@selector(targetMethod)
    userInfo:nil
    repeats:NO];

在动画结束后调用：

-(void)targetMethod
{
     flowerImageView.hidden = YES;
}

 CABasicAnimation *theAnimation;
 theAnimation=[CABasicAnimation animationWithKeyPath:@"opacity"];
 theAnimation.duration=1.0;
 theAnimation.fromValue=[NSNumber numberWithFloat:1.0];
 theAnimation.toValue=[NSNumber numberWithFloat:0.0];
 [flowerImageView.layer addAnimation:theAnimation forKey:@"animateOpacity"];

 [NSTimer scheduledTimerWithTimeInterval:theAnimation.duration
    target:self
    selector:@selector(targetMethod)
    userInfo:nil
    repeats:NO];  

在动画结束后，imageview就会完全隐藏。

-(void)targetMethod
{
     [flowerImageView setHidden:YES];
}