两次调用 removeFromSuperview 会导致崩溃或副作用 [英] will calling removeFromSuperview twice cause a crash or side effect

问题描述

我有一个 UIView 元素，我将它添加到主视图控制器中.

I have a UIView element which I am adding to the main view controller.

由于我的代码的设计，removeFromSuperview 在我的代码的不同位置被调用了两次.

Due to the design of my code, it so happens that the removeFromSuperview is called twice in different places of my code.

[myview removeFromSuperview];

这就是我的代码，所以我想知道调用removeFromSuperview"是否会导致任何问题.

That is how my code is, so I want to know if calling the 'removeFromSuperview' causes any problem.

或者如何检查视图是否在超级视图中并且仅将其删除.

Or how do I check if the view is in the superview and only the remove it.

例如

if (myview in superview)
    [myview removeFromSuperview];
else
    do nothing

推荐答案

removeFromSuperview 的文档说明如下:

如果接收者的superview不为nil，则superview释放接收者.如果您打算重用视图，请务必在之前保留它调用此方法，稍后根据需要再次释放.

If the receiver’s superview is not nil, the superview releases the receiver. If you plan to reuse a view, be sure to retain it before calling this method and release it again later as appropriate.

这意味着不应该发生崩溃或副作用，并且您所询问的检查已经由该方法的实现执行了.

It means that no crash or side effect should happen, and a check you're asking about is already performed by the implementation of this method.

但是，如果您需要检查您的视图是否作为子视图添加到其他视图中，您可以使用以下代码:

However, if you need to check if your view is added as subview to some other view, you can use the following code:

if( theView.superview != nil )
{
  // theView is a subview for some view
}

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