iPhone/iPad -核心动画- CGAffineTransformMakeTranslation不会修改框架

Question

我正面临一个非常恼人的问题。这是context:我有一个矩形视图它是主视图的子视图。我想做的很简单，当我点击一个按钮时，我想要"矩形"视图在x轴上平移，以便消失。然后，我添加一个新的子视图，并将其转换，以取代之前的"矩形"视图。它的工作很好，除了如果我再次按下按钮，动画将开始离开屏幕，像CGAffineTransformMakeTranslation没有改变我的新"矩形"视图的框架。下面是代码:

UIView *rectangleView = [detailView viewWithTag:4]; //the actual frame is (20.0, 30.0, 884.0, 600.0)
[UIView animateWithDuration:0.5 animations:^{
    [rectangleView setTransform:CGAffineTransformMakeTranslation(-1000, 0)];
} completion:^(BOOL finished) {
    [rectangleView removeFromSuperview];
    UIView *otherView = [[UIView alloc] initWithFrame:CGRectMake(1020.0, 30.0, 884.0, 600.0)];
    [otherView setBackgroundColor:[UIColor purpleColor]];
    [otherView setTag:4];
    [detailView addSubview:otherView];
    [UIView animateWithDuration:0.5 animations:^{
        [otherView setTransform:CGAffineTransformMakeTranslation(-1000, 0)];
    } completion:^(BOOL finished) {
        [otherView release];
    }];
}];

Answer 1

添加第二个视图后，您已经将其转换设置为等于CGAffineTransformMakeTranslation(-1000, 0)，并且当您想要删除该视图时，您设置完全相同的转换-因此它将没有效果。这里有两个选项:

1. 对视图已有的转换应用转换:

   CGAffineTransform newTransform = CGAffineTransformConcat(rectangleView.transform, CGAffineTransformMakeTranslation(-1000, 0));
   [rectangleView setTransform:newTransform];
   

2. 不直接对视图位置进行变换操作(例如通过其center属性)

   UIView *rectangleView = [detailView viewWithTag:4]; //the actual frame is (20.0, 30.0, 884.0, 600.0)
   CGAffineTransform tf = CGAffineTransformMakeTranslation(-1000, 0);
   [UIView animateWithDuration:0.5 animations:^{
       [rectangleView setCenter: CGPointApplyAffineTransform(rectangleView.center, tf)];
   } completion:^(BOOL finished) {
       [rectangleView removeFromSuperview];
       UIView *otherView = [[UIView alloc] initWithFrame:CGRectMake(1020.0, 30.0, 884.0, 600.0)];
       [otherView setBackgroundColor:[UIColor purpleColor]];
       [otherView setTag:4];
       [detailView addSubview:otherView];
       [UIView animateWithDuration:0.5 animations:^{
           [otherView setCenter: CGPointApplyAffineTransform(otherView.center, tf)];
       } completion:^(BOOL finished) {
           [otherView release];
       }];
   }];
   

Answer 2

尝试将center属性动画化而不是使用仿射变换。转换不是附加的，所以你的第二个动画(当你新添加的细节视图被移出屏幕时)实际上根本没有改变视图，因为它已经应用了转换(-1000,0)。