如何检测是否从导航控制器中弹出了视图控制器？ [英] How to detect if view controller is being popped of from the navigation controller?

问题描述

当我从导航控制器弹出顶视图控制器时，我当前需要实现一些代码。有没有办法检测视图控制器何时从导航控制器堆栈弹出？

I currently need to implement some code when the top view controller is being popped off from my navigation controller. Is there a way to detect when the view controller is being popped off the navigation controller stack?

我想尽可能远离使用 viewWillDisappear 或 viewDidDisappear 因为我在我的项目中使用 splitview ，并且在主视图中选择另一行也会触发 viewWillDisappear / viewDidDisappear methods。

As much as possible I want to stay away from using viewWillDisappear or viewDidDisappear because I'm using a splitview in my project, and selecting a different row in the master view will also trigger the viewWillDisappear/viewDidDisappear methods.

推荐答案

你可以使用视图控制器的 isMovingFromParentViewController 属性检测是否正在弹出视图，如下所示：

You can detect whether a view is being popped using the isMovingFromParentViewController property for a view controller as shown below:

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    if ([self isMovingFromParentViewController])
    {
        NSLog(@"View controller was popped");
    }
    else
    {
        NSLog(@"New view controller was pushed");
    }
}

< a href =https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIViewController_Class/index.html#//apple_ref/occ/instm/UIViewController/isMovingFromParentViewController> isMovingFromParentViewController

isMovingFromParentViewController

返回一个布尔值，指示视图控制器在
中从父项中删除的过程。

Returns a Boolean value that indicates that the view controller is in the process of being removed from its parent.

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