如何在iphone应用程序中添加pop视图控制器的通知？

Question

我见过iPhone MP-movie player的示例应用程序 - 控制器.

他们在示例代码中添加了通知.

// Register to receive a notification that the movie is now in memory and ready to play
[[NSNotificationCenter defaultCenter] addObserver:self 
                 selector:@selector(moviePreloadDidFinish:) 
                 name:MPMoviePlayerContentPreloadDidFinishNotification 
                 object:nil];

在上面的代码中,当MPMoviePlayerController完成加载时,它会调用moviePreloadDidFinish方法.

同样,我想在用户按下导航栏上的按钮(通过导航控制器返回上一个视图控制器)时触发一个方法.

我不知道如何为此添加通知.

Answer 1

将您自己的自定义后退按钮放在navigationItem:

UIBarButtonItem *btn = [[UIBarButtonItem alloc] initWithImage:yourImage style:UIBarButtonItemStyleBordered target:self action:@selector(goBack)];
self.navigationItem.leftBarButtonItem = btn;
[btn release];

在goBackviewController 的方法中,你将放置你需要的任何代码,然后弹出viewController:

- (void)goBack {
 /* your code here */

[self.view.navigationController popToRootViewControllerAnimated:YES];
}