ios - NavigationController 更改后退按钮

Question

我有两个问题:

问题 1:我正在尝试更改导航后退按钮，我正在从父 ViewController 执行此操作:

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"imgrdy"]) {
        VCImageEditingViewController *ieVC = (VCImageEditingViewController *)segue.destinationViewController;
        UIBarButtonItem *newBackButton = [[UIBarButtonItem alloc] initWithTitle: @"New" style:UIBarButtonItemStyleBordered target:nil action:@selector(handleNewBtnNav:)];
        [[self navigationItem] setBackBarButtonItem: newBackButton];    
    }
}
-(IBAction)handleNewBtnNav:(id)sender {
    UIAlertView *alertNew = [[UIAlertView alloc]initWithTitle:@"New photo" message:@"Are you sure?" delegate:self cancelButtonTitle:@"ok" otherButtonTitles: nil];
    [alertNew show];
}

标题确实已更改，但未显示警报。我尝试将目标更改为“self”和“ieVC”，但仍然没有。

问题 2:有没有办法只改变一个 ViewController 的后退按钮的标题？还是我必须对每个父 ViewController 进行相同的更改？

谢谢。

Answer 1

在声明按钮时使用 target:self，它是 Action 的接收者，你说它是 nil

UIBarButtonItem *newBackButton = [[UIBarButtonItem alloc] initWithTitle: @"New" style:UIBarButtonItemStyleBordered target:self action:@selector(handleNewBtnNav:)];