Question

我有这个代码：

-(void)animationLoop{
CGPoint oldPoint = CGPointMake(myCircleUIView.frame.origin.x, myCircleUIView.frame.origin.y);
[UIView animateWithDuration:1.0
                 animations: ^{ myCircleUIView.frame = CGRectMake(myCircleUIView.frame.origin.x + [self randomFloatingGenerator], myCircleUIView.frame.origin.y + [self randomFloatingGenerator], myCircleUIView.frame.size.width, myCircleUIView.frame.size.height); }
                 completion:
 ^(BOOL finished) {
     [UIView animateWithDuration:1.0
                      animations:^{ myCircleUIView.frame = CGRectMake(oldPoint.x, oldPoint.y, myCircleUIView.frame.size.width, myCircleUIView.frame.size.height);}
                      completion:
      ^(BOOL finished) {[self animationLoop];}];
 }];
}

但是我试图在与它交互时停止动画，但是[myCircleUIView.layer removeAllAnimations];不会做任何建议吗？

Answer 1

当您使用CALayer's -removeAllAnimations停止动画时，将使用finished == NO调用回调。所以改变你的动画代码如下：

- (void)animationLoop {
    __weak id weakSelf = self;
    CGPoint oldPoint = CGPointMake(myCircleUIView.frame.origin.x, myCircleUIView.frame.origin.y);
    [UIView animateWithDuration:1.0
                     animations:^{
                         myCircleUIView.frame = CGRectMake(myCircleUIView.frame.origin.x + [weakSelf randomFloatingGenerator], myCircleUIView.frame.origin.y + [weakSelf randomFloatingGenerator], myCircleUIView.frame.size.width, myCircleUIView.frame.size.height);
                     }
                     completion:^(BOOL finished) {
                         if (!finished) return;
                         [UIView animateWithDuration:1.0
                                          animations:^{
                                              myCircleUIView.frame = CGRectMake(oldPoint.x, oldPoint.y, myCircleUIView.frame.size.width, myCircleUIView.frame.size.height);
                                          }
                                          completion:^(BOOL finished) {
                                              if (!finished) return;
                                              [weakSelf animationLoop];
                                          }];
                     }];
}

我还建议你不要将对self的强引用传递给复制到堆的块，如果你真的不想因为可能retain cycle。

Answer 2

在你的循环中添加bool并在需要停止动画时设置为false，如下面的代码所示......

BOOL IsAnimationContinue=true;

-(void)animationLoop{
CGPoint oldPoint = CGPointMake(myCircleUIView.frame.origin.x, myCircleUIView.frame.origin.y);
[UIView animateWithDuration:1.0
             animations: ^{
                              if(IsAnimationContinue)
                              {
                               myCircleUIView.frame = CGRectMake(myCircleUIView.frame.origin.x + [self randomFloatingGenerator], myCircleUIView.frame.origin.y + [self randomFloatingGenerator], myCircleUIView.frame.size.width, myCircleUIView.frame.size.height); 
                              }}
             completion:^(BOOL finished) {
 [UIView animateWithDuration:1.0
                  animations:^{ 
                                 if(IsAnimationContinue)
                                {
                                 myCircleUIView.frame = CGRectMake(oldPoint.x, oldPoint.y, myCircleUIView.frame.size.width, myCircleUIView.frame.size.height);
                                }}
                  completion:
  ^(BOOL finished) {[self animationLoop];}];

}]; }

只需设置

IsAnimationContinue=False

停止动画

如何在需要时停止UIView动画？

2 个答案: