将视图移动到新的超级视图而不会闪烁

Question

作为动画的一部分，我有一个视图，我想更深入地进入视图层次结构。 （我之前将它移动到视图层次结构的顶部，以便执行显示在其他UI元素之上的动画。）我正在使用此代码，它执行正确的操作。

CGRect rect = self.profileImage.frame;
UIView *sv = self.profileImage.superview;
[self.scrollview addSubview:self.profileImage];
rect = [self.scrollview convertRect:rect fromView:sv];
self.profileImage.frame = rect;

但是，当我这样做时，视图会闪烁。任何想法如何避免闪烁？

Answer 1

尝试

CGRect rect = self.profileImage.frame;
UIView *sv = self.profileImage.superview;
rect = [self.scrollview convertRect:rect fromView:sv];
self.profileImage.frame = rect;
[self.scrollview addSubview:self.profileImage];

或

CGRect rect = self.profileImage.frame;
UIView *sv = self.profileImage.superview;
self.profileImage.alpha = 0.0f;
rect = [self.scrollview convertRect:rect fromView:sv];
self.profileImage.frame = rect;
[self.scrollview addSubview:self.profileImage];
[UIView animateWithDuration:0.0f animations:^{
    self.profileImage.alpha = 1.0f;
}];

Answer 2

我在没有闪烁的情况下使用了这个：

CGRect rect = self.profileImage.frame;
UIView *sv = self.profileImage.superview;
CGRect convertedRect = [self.scrollview convertRect:rect fromView:sv];
[UIView animateWithDuration:0.0 animations:^(void){
    [self.profileImage setAlpha:0.0];
    [self.profileImage setFrame:convertFrame];
    [self.scrollview addSubview:self.profileImage];
    [self.profileImage setAlpha:1.0];
}];

Answer 3

在我的情况下，问题是addSubview是在后台线程中执行的。 您需要在主队列上执行更改，它应该可以正常工作。

尝试

dispatch_async(dispatch_get_main_queue(), ^{
  CGRect rect = self.profileImage.frame;
  UIView *sv = self.profileImage.superview;
  [self.scrollview addSubview:self.profileImage];
  rect = [self.scrollview convertRect:rect fromView:sv];
  self.profileImage.frame = rect;
}