Question

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

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

- (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。

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

不会调用viewWillAppear，viewDidAppear，viewDidDisappear，viewDidUnLoad。

Answer 1

如果您只想覆盖左侧导航栏按钮的行为，您只需将leftBarButtonItem替换为带有自定义操作的按钮：

// 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];

如果您愿意，还可以为UIBarButtonItem提供自定义视图。

Answer 2

您应该在父视图控制器中调用viewWillAppear。

http://bit.ly/q9vQiu

为什么不调用viewWillDisapper？

2 个答案: