iPhone/iPad - 核心动画 - CGAffineTransformMakeTranslation 不修改框架

Question

我面临着一个非常烦人的问题。这是上下文:我有一个“矩形” View ，它是主视图的 subview 。我想做的很简单，当我单击按钮时，我希望“矩形” View 在 x 轴上平移以便消失。然后，我添加一个新的 subview 并对其进行翻译，以取代之前的“矩形” View 。它工作正常，只是如果我再次按下按钮，动画将从屏幕上开始，就像 CGAffineTransformMakeTranslation 没有更改我的新“矩形” View 的框架一样。代码如下:

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 View 后，您已经将其变换设置为等于CGAffineTransformMakeTranslation(-1000, 0)，并且当您想要删除该 View 时，您设置了完全相同的变换 - 所以它不会有任何影响。您这里有 2 个选择:

1. 将翻译应用于 View 已有的转换:

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

2. 不直接应用 View 位置操作变换(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];
       }];
   }];