iOS两个视图覆盖父视图的一半 [英] iOS two views cover exactly half of parent view

问题描述

在我的应用程式中，我要实现这种布局：

因此，父视图包含两个子视图。第一个开始正好在中间（高度/ 2），第二个开始在父视图的中间。我发现这是不可能的，在IB中的约束。所以我在 viewDidLoad 方法中使用这个代码：

  NSLayoutConstraint * constraint = [NSLayoutConstraint constraintWithItem：firstView 
 attribute：NSLayoutAttributeHeight 
 relatedBy：0 
 toItem：self.view 
 attribute：NSLayoutAttributeHeight 
 multiplier：0.5 
 constant：0] ; 
 
 [self.view addConstraint：constraint]; 
  

现在可以使用，但只有当应用程序在iPhone上运行时。因为视图的大小是像iPhone屏幕。如果这个应用程序运行在iPad上，有一个问题，因为屏幕有不同的大小，所以这个父视图更长。约束（上面的代码）仍然需要来自IB的视图大小的0.5 *大小，而不是从视图的iPad大小。

结果是此视图具有相同的大小。

$ toItem：self.view 在iPad中像在iPhone。在iPad中有一个大的空格，然后有一个视图与iPhone的大小。

你能告诉我要做什么，使其通用的各种屏幕尺寸？非常感谢

解决方案

确定，所以我只是想出了如何做到这一点。只需将代码放入 viewDidLayoutSubviews 方法中，而不是 viewDidLoad 。我在主题中找到的解决方案无法在viewDidAppear之前正确设置框架 。

这是我的代码：

  [subView1 setFrame：CGRectMake （0，0，self.view.frame.size.width，self.view.frame.size.height / 2）]; 
 [subView2 setFrame：CGRectMake（0，self.view.frame.size.height / 2，self.view.frame.size.width，self.view.frame.size.height / 2）]; 
  

感谢所有人的努力！

In my app I want to achieve this layout:

So parent view contains two sub views. First one ends exactly in a middle (height / 2) and second starts in a middle of parent view. I have found out that it is impossible to do that in the IB with constraints. So I used this code in viewDidLoad method:

NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem:firstView
                                                              attribute:NSLayoutAttributeHeight
                                                              relatedBy:0
                                                                 toItem:self.view
                                                              attribute:NSLayoutAttributeHeight
                                                             multiplier:0.5
                                                               constant:0];

[self.view addConstraint:constraint];

Now it works but only if the app runs on the iPhone. Because size of the view is like iPhone screen. If this app runs on the iPad, there is a problem because screen has different size so this parent view is longer. And constraint (code above) still takes 0.5 * size of the views size from the IB and not size from the iPad size of the view. Item toItem:self.view still takes size from the IB.

Result is that this view has a same size in the iPad as in the iPhone. In the iPad there is a large blank space and then there is a view with iPhone size.

Can you tell what I have to do to make it universal for various screen sizes? Thank you very much

解决方案

OK so I just figured out how to do this. Simply put the code into viewDidLayoutSubviews method and not to viewDidLoad. The solution I found in the topic Unable to set frame correctly before viewDidAppear.

Here is my code:

[subView1 setFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height / 2)];
[subView2 setFrame:CGRectMake(0, self.view.frame.size.height / 2, self.view.frame.size.width, self.view.frame.size.height / 2)];

Thanks to all for effort!

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