小编rec*_*ens的帖子

当有人按下我的iOS应用程序的"后退"按钮时,我想添加一个弹出窗口,询问用户他是否真的想回来.然后,根据用户的响应,我想撤消操作或继续.我试图在我的视图的viewWillDisappear函数中添加代码然后编写正确的委托但它不起作用,因为它总是更改视图然后显示弹出窗口.我的代码是:

    -(void) viewWillDisappear:(BOOL)animated {
       _animated = animated;
       if ([self.navigationController.viewControllers indexOfObject:self]==NSNotFound) {
           UIAlertView *alert_undo = [[UIAlertView alloc] initWithTitle:@"UIAlertView"
                                                                message:@"You could be    loosing information with this action. Do you want to proceed?"
                                                               delegate:self
                                                      cancelButtonTitle:@"Go back"
                                                      otherButtonTitles:@"Yes", nil];
           [alert_undo show];
       }
       else [super viewWillDisappear:animated];
   }

代表实现是:

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    NSString *title = [alertView buttonTitleAtIndex:buttonIndex];
    if([title isEqualToString:@"Yes"])
    {
        [super viewWillDisappear:_animated];
    }
}

这根本不起作用.现在有人有更好的方法去做或可能出错吗？

非常感谢你,