为什么不调用viewWillDisapper? [英] Why is viewWillDisapper not called?

问题描述

为什么当我在myViewController的导航栏中按下后退按钮时，为什么没有调用viewWillDisapper?

Why is viewWillDisapper not called when I push back button in navigation bar of myViewController?

TheController *theController = [[TheController alloc] initWithStyle:UITableViewStylePlain];             
UINavigationController *aNavigationController = [[UINavigationController alloc] initWithRootViewController:theController];
self.naviController = aNavigationController;
[aNavigationController release];
[theController release];
[self.view addSubview:naviController.view];

//这是TheController.m

// This is TheController.m

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    MyViewController *myViewController = [[MyViewController alloc] init];           
    [self.navigationController pushViewController:myViewController animated:YES];
    [myViewController release];
}

//这是MyViewController.m.MyViewConroller是UIViewController的子类.

// This is MyViewController.m. MyViewConroller is subclass of UIViewController.

- (void)viewWillDisappear:(BOOL)animated {
    // I want to override back button behavior. But, this is not called.
}

viewWillAppear，viewDidAppear，viewDidDisappear，viewDidUnLoad也不会被调用.

viewWillAppear, viewDidAppear, viewDidDisappear, viewDidUnLoad are not called either.

推荐答案

如果只想覆盖左侧导航栏按钮的行为，则可以简单地将leftBarButtonItem替换为具有自定义操作的按钮:

If you just want to override the left navigation bar button behavior, you can simply replace the leftBarButtonItem with a button with a custom action:

// Place this in you viewDidLoad method
UIBarButtonItem *customBack = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonSystemItemCancel target:self action:@selector(customAction)];
self.navigationItem.leftBarButtonItem = customBack;
[customBack release];

如果愿意，还可以为UIBarButtonItem提供自定义视图.

You can also provide a custom view for the UIBarButtonItem if you prefer.

这篇关于为什么不调用viewWillDisapper?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！