我是 iOS 新手。在我的子视图控制器中，我对数据进行了一些修改。我插入了一个完成按钮来存储数据并从导航控制器堆栈中弹出视图控制器。如果我按下导航控制器后退按钮，它会自动返回而不保存数据。如果我对数据进行了任何修改，然后我按下了返回按钮，我需要显示警报，因为“进行了修改肯定要返回”。如果用户在警报视图中按下取消按钮，我需要停止视图消失并仍然站在同一个视图控制器上。如果有人有答案，请帮助我。
【问题讨论】：
标签： ios objective-c iphone
我认为这是一种方法
- (void)viewDidLoad{
[super viewDidLoad];
[self.navigationItem setLeftBarButtonItem:nil];
[self.navigationItem setHidesBackButton:YES];
UIButton *myButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 100, 44)];
[myButton setImage:[UIImage imageNamed:@"back.png"] forState:UIControlStateNormal];
//back.png = your image name
[myButton setTitle:@"Back" forState:UIControlStateNormal];
[myButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[myButton addTarget:self action:@selector(backButtonTapped:) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *customBackButton = [[UIBarButtonItem alloc] initWithCustomView:myButton];
[self.navigationItem setLeftBarButtonItem:customBackButton];
}
- (void)backButtonTapped:(id)sender{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Message" message:@"modifications are made are sure want to go back" delegate:self cancelButtonTitle:@"Go Back" otherButtonTitles:@"Stay Here", nil];
[alert show];
}
- (void)alertView:(UIAlertView *)alertView
clickedButtonAtIndex:(NSInteger)buttonIndex{
if (buttonIndex == [alertView cancelButtonIndex]){
[self.navigationController popViewControllerAnimated:YES];
}else{
//Stay on the page and do something
}
}
别忘了加<UIAlertViewDelegate>
【讨论】：