问题与自动布局在iOS 8（code完美的作品在iOS 7） [英] Issue with Auto Layout on iOS 8 (code works perfectly on iOS 7)
问题描述
我有一个用自动布局和内置应用程序的一切仍然有效，当我在我的iOS运行7设备如预期，但是当我在一个运行iOS的设备8我的一些约束条件去有点古怪。
I have an app that was built using auto-layout and everything still works as expected when I run it on my iOS 7 device, however when I run it on an iOS 8 device some of my constraints go a little wacky.
我居然经历了另一个应用程序类似的问题，但它不是一个大问题。现在，我开始怀疑它在iOS的8 SDK错误或是否有处理在iOS8上汽车的布局，我不知道的新途径。
I actually experienced a similar issue in another app but it wasn't a big issue. Now, I'm starting to wonder if it is a bug in the iOS 8 SDK or if there is a new way of handling auto layout in iOS8 that I'm not aware of.
下面是我的设置：
我有一个的UIView 与嵌入了的UIImageView 。无论是视图和图像视图有限制的牵制下，领导和放大器;后缘其与superviews常数= 0
Here is my setup:
I have a UIView with a UIImageView embedded inside it. Both the view and the image view have constraints pinning their bottom, leading & trailing edges to their superviews with constant = 0.
的的UIView 也有其固定到它的父顶部边缘，我有一个IBOutlet连接约束，以编程方式调整。在的UIImageView 的第四个约束它的高度固定在装置的高度（在我的案件568）。
The UIView also has its top edge pinned to its superview and I have an IBOutlet connected to the constraint in order to adjust it programatically. The UIImageView has a fourth constraint fixing its height to the height of the device (in my case 568).
下面是我期待/ iOS中7实现的行为：
我试图缩小容器视图的高度，使图像视图顶部的W / O宽高比改变被切断（有点貌似你裁剪图像关闭的顶部）......这是为什么我已经固定图像视图和底边的高度。
Here is the behavior I am expecting/achieving in iOS 7: I am trying to shrink the height of the container view and cause the top of the image view to be cut off w/o the aspect ratio changing (sort of looks like you cropped the top of the image off)...this is why I have pinned the height of the image view and the bottom edge.
实际上发生在iOS8上什么：
容器视图收缩预期（它保持固定在两侧和放大器;底部＆放大器;高度收缩）。在的UIImageView 的行为就好像它与cosntant == 0，而不是切断图像的顶部顶部空间限制，整个图像逐渐缩小。由于我在 AspectFit 模式下，图像，两侧捏住以及保持纵横比相同（但ImageView的本身仍然固定在领导，拖尾和放大器;底部边，因为它应该）。
What actually happens in iOS8:
The container view shrinks as expected (it stays pinned to the sides & bottom & the height shrinks). The UIImageView behaves as if it had a top space constraint with cosntant == 0. Instead of cutting off the top of the image, the whole image shrinks down. Since I have the image in AspectFit mode, the sides pinch in as well to keep the aspect ratio the same (but the imageView itself remains pinned to the leading, trailing & bottom edges as it should).
我是怎么做的：
我有一个从我的code的另一部分触发调整挂在IBOutlet中顶部空间约束的通知。它调用该方法其实非常简单：
How I do it: I have a notification that fires from another part of my code to adjust the top-space constraint hooked up to the IBOutlet. The method it calls is really quite simple:
- (void) setTopSpaceForContainerView:(NSNotification*) notif{
containerView_TopSpace.constant = [[notif.userInfo objectForKey:kTopSpace] intValue];
[self.view setNeedsUpdateConstraints];
[self.view setNeedsLayout];
}
任何人有类似的经历？我试图找到一个解决办法，但iOS的8只似乎决心要缩小我的形象。
Anyone else have a similar experience? I'm trying to find a workaround, but iOS 8 just seems determined to shrink my image.
由于一吨！
推荐答案
这绝对是一个iOS 8的错误。我可以通过发送 setNeedsLayout 到容器视图（图像视图的上海华）来解决它。
This is definitely an iOS 8 bug. I was able to work around it by sending setNeedsLayout to the container view (the superview of the image view).
我看到你发送 setNeedsLayout 到 self.view 。如果code是在你的视图控制器，那么我想<$ C $ C> self.view 不是容器视图。试着发送 setNeedsLayout 直接在容器视图。
I see that you're sending setNeedsLayout to self.view. If that code is in your view controller, then I guess self.view is not the container view. Try sending setNeedsLayout to the container view directly.
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