缩小然后关闭 UIView 的问题

Question

我有一个自定义视图，我用动画呈现，提供弹跳效果。现在，我希望它以类似于收缩然后消失的方式消失。

下面一段代码以弹跳效果呈现我的视图，工作正常：

self.componentDetailController.view.center = iGestureRecognizer.view.center;
self.componentDetailController.view.alpha = 0.0;
self.componentDetailController.view.transform = CGAffineTransformMakeScale(0.01, 0.01);
 [UIView animateWithDuration:(0.2) animations:^{
     self.componentDetailController.view.center = CGPointMake(kScreenWidth / 2, kScreenHeight / 2);
     self.componentDetailController.view.alpha = 0.5;
     self.componentDetailController.view.transform = CGAffineTransformMakeScale(1.05, 1.05);
 } completion:^(BOOL iFinished) {
     [UIView animateWithDuration:(0.1) animations:^{
         self.componentDetailController.view.alpha = 0.90;
         self.componentDetailController.view.center = CGPointMake(kScreenWidth / 2, kScreenHeight / 2);
         self.componentDetailController.view.transform = CGAffineTransformMakeScale(0.98, 0.98);
     } completion:^(BOOL iFinished) {
         self.componentDetailController.view.alpha = 1.0;
         self.componentDetailController.view.transform = CGAffineTransformMakeScale(1.0, 1.0);
         self.componentDetailController.view.transform = CGAffineTransformIdentity;
     }];
 }];

我编写了以下代码来缩小和关闭不起作用的视图。它把视野带到了前面一点，但随后并没有忽视它。任何线索这里出了什么问题：

 - (void)cancelButtonPressed {
    self.componentDetailController.view.transform = CGAffineTransformIdentity;
    [UIView animateWithDuration:(0.1) animations:^{
        self.componentDetailController.view.alpha = 1.0;
        self.componentDetailController.view.transform = CGAffineTransformMakeScale(1.05, 1.05);
    } completion:^(BOOL iFinished) {
        [UIView animateWithDuration:(0.4) animations:^{
            self.componentDetailController.view.center = self.tappedComponentView.center;
            self.componentDetailController.view.transform = CGAffineTransformMakeScale(0.01, 0.01);
            self.componentDetailController.view.backgroundColor = [UIColor clearColor];
            self.componentDetailController.view.alpha = 0.0;
        } completion:^(BOOL iFinished) {
            [self.componentDetailController.view removeFromSuperview];
        }];
    }];
    self.componentDetailController = nil;
    [self enableBackView];
}

在这里，self.tappedComponentView.center与self.tappedComponentView.center相同。

Answer 1

+animateWithDuration:animations:completion: 调用会立即返回，因此一旦第二个动画运行，self.componentDetailController就会nil，并且所有后续的视图转换调用都无处可去。将self.componentDetailController.view存储到其自己的变量中，并在动画块中引用该变量。例如：

UIView *detailView = self.componentDetailController.view;
detailView.transform = CGAffineTransformIdentity;
[UIView animateWithDuration:0.1 animations:^{
    detailView.alpha = 1;
// …
}];
self.componentDetailController = nil;