ios - UIAlertView在performSelector中包含dismissWithClickedButtonIndex后不断重新出现 : withObject: afterDelay:

Question

我有一个按钮，如果密码正确，我想在触发 segue 之前使用密码实现。当您输入错误的密码时，一切看起来都很好，我已经实现了另一个alertView来告诉用户密码是错误的。 当警报 View 弹出并在延迟一段时间后消失时，它会不断重新出现和消失，并且屏幕上无法执行任何其他操作!如何阻止再次出现？下面是我处理此问题的代码部分:

- (IBAction)editLeagues:(id)sender {

    [self presentAlertViewForPassword];

}

-(void)presentAlertViewForPassword
{

    _passwordAlert = [[UIAlertView alloc]initWithTitle:@"Password"
                                                           message:@"Enter Password to edit Leagues"
                                                          delegate:self
                                                 cancelButtonTitle:@"Cancel"
                                                 otherButtonTitles:@"OK", nil];
    [_passwordAlert setAlertViewStyle:UIAlertViewStyleSecureTextInput];
    _passwordField = [_passwordAlert textFieldAtIndex:0];
    _passwordField.delegate = self;
    _passwordField.autocapitalizationType = UITextAutocapitalizationTypeWords;
    _passwordField.tag = textFieldPassword;
    [_passwordAlert show];

}

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
    NSString *password = [NSString stringWithFormat:@"55555"];

      if ( ![_passwordField.text isEqual:password]) {

          _wrongPassword = [[UIAlertView alloc] initWithTitle:@"Wrong Password"
                                                                message:@"You are not authorised to use this feature!"
                                                               delegate:self
                                                      cancelButtonTitle:nil
                                                      otherButtonTitles:nil];
        [_wrongPassword show];

        [self performSelector:@selector(allertViewDelayedDissmiss:) withObject:nil afterDelay:2];
    }
    else
    {
         [self performSegueWithIdentifier:@"addLeague" sender:[alertView buttonTitleAtIndex:0]];
    }

}

-(void) allertViewDelayedDissmiss:(UIAlertView *)alertView
{
    [_wrongPassword dismissWithClickedButtonIndex:-1 animated:YES];

}


- (BOOL)alertViewShouldEnableFirstOtherButton:(UIAlertView *)alertView
{
    NSString *inputText = [[alertView textFieldAtIndex:0] text];
    if( [inputText length] >= 4 )
    {
        return YES;
    }
    else
    {
        return NO;
    }
}

Answer 1

[_wrongPasswordmissWithClickedButtonIndex:-1animated:YES]; 将调用委托(delegate)方法alertView:didDismissWithButtonIndex:

您有两个选择:

1. 不要设置代表密码错误警报

2. 检查 alertView:didDismissWithButtonIndex: 中的警报是否正确

   - (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
   {
       if (alert == _passwordAlert) {
           NSString *password = [NSString stringWithFormat:@"55555"];
           // and so on
       }
   }