切换选项卡选择后更新UIViewControllers

问题描述

我在一个标签栏中有两个视图控制器，它们都可以编辑数据.因此，每当用户在选项卡栏上进行切换时，我都需要调用reload_data函数.如何捕捉开关或视图控制器的外观.标签栏开关上不以某种方式调用viewDidAppear.而且我不想为此使用tabbarController委托，因为几个viewController会受到影响(而且我无法将它们全部设置为委托).解决这个问题的好方法是什么?

I have two view controllers in a tabbar which can both edit data. Therefore, I need to call a reload_data function whenever the user makes a switch on the tabbar. How can I catch the switch or the appearance of the viewcontroller. Somehow viewDidAppear is not called on a tabbar switch. And I do not want to use the tabbarController delegate for this, because several viewControllers are affected (and I cannot set them all as delegate). What is a good way to solve this?

例如这不起作用:

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:YES];
    [self reloadData];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:YES];
    [self reloadData];
}

推荐答案

如果您使用的是Interface Builder，请确保定义了希望重新加载的viewController的类(在IB中选择ViewController，然后选择CMD-4，确保将类定义为您要调用viewWillAppear和viewDidAppear的类.

If you're using Interface Builder, make sure the class for the viewController your expecting to reload is defined (Select the ViewController in IB, then CMD-4, make sure class is defined to be the class you want viewWillAppear and viewDidAppear to be called in).

如果您不使用IB，请发布用于初始化/调用viewController的代码.

If you're not using IB, post your code for init/calling the viewController.

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