旋转UIView时覆盖layoutSubviews [英] Overriding layoutSubviews when rotating UIView

问题描述

在UIView内旋转滚动视图时，滚动视图无法使用其默认的自动调整行为正确定位。

When rotating a scroll view inside a UIView, the scroll view doesnt position correctly using its default autoresizing behaviour.

因此，当轮换发生时，在 willRotateToInterfaceOrientation 我调用 [self.view setNeedsLayout] ; 和我的 layoutSubviews 方法如下：

Thus, when rotation occurs, in willRotateToInterfaceOrientation i call [self.view setNeedsLayout]; and my layoutSubviews method is as follows:

- (void)layoutSubviews {
    NSLog(@"here in layoutSubviews");
}

但是在方法上设置一个断点，它似乎永远不会进入方法。

But putting a breakpoint on the method, and it never seems to enter the method.

我是否需要做其他事情才能让它发挥作用？

Do i need to do something else to get it to work?

谢谢。

推荐答案

在更改方向之前调用willRotateToInterfaceOrientation，因此您的UIView仍将具有旧的大小。
尝试使用didRotateFromInterfaceOrientation。

willRotateToInterfaceOrientation is being called before the orientation is changed, hence your UIView will still have the old size. Try using didRotateFromInterfaceOrientation instead.

另外，为了增加效果，我会在willRotateToInterfaceOrientation中隐藏scrollView（可能在UIAnimation块内），调整大小然后再调整它在didRotateFromInterfaceOrientation中显示它（再次，可能在动画块内）。

Also, for added effect, I would hide the scrollView ( maybe with inside an UIAnimation block) in willRotateToInterfaceOrientation, resize it and then show it in didRotateFromInterfaceOrientation (again, maybe inside an animation block).

这是我的一个应用程序的片段：

Here is a snippet from one of my apps:

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.3f];
self.myScroll.hidden = YES;
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
[UIView commitAnimations];
}

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.3f];
self.myScroll.hidden = NO;
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
[UIView commitAnimations];
}

您甚至可以通过使用UIInterfaceOrientationIsPortrait（方向）检查新方向来做一些奇特的事情或UIInterfaceOrientationIsLandscape（方向）。

You can even do fancy stuff by checking the new orientation using UIInterfaceOrientationIsPortrait(orientation) or UIInterfaceOrientationIsLandscape(orientation).

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