ios - 多个 UIAlertViews 的错误/错误

Question

我在使用 UIAlertViews 时遇到了一个非常奇怪的错误。把我的头发弄得乱七八糟，请帮帮我!

当我按下“创建!”时发生错误在 alert1 警报中，checkUsernameExists 返回 true，然后我按“K”。在 alert3 中。

代码

-(void) newProfile:(id)sender {
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"New Profile"
                                                    message:nil
                                                   delegate:self
                                          cancelButtonTitle:@"Create!"
                                          otherButtonTitles:nil];

    alert.alertViewStyle = UIAlertViewStyleLoginAndPasswordInput;

    UITextField *username = [alert textFieldAtIndex:0];
    username.keyboardType = UIKeyboardTypeDefault;
    username.placeholder = @"Desired Username";

    UITextField *password = [alert textFieldAtIndex:1];
    password.keyboardType = UIKeyboardTypeDefault;
    password.placeholder = @"Desired Password";

    [alert1 show];
}
- (void)alertView:(UIAlertView *)alert clickedButtonAtIndex:(NSInteger)buttonIndex {
    NSString *title = [alert title];
    UITextField *username = [alert textFieldAtIndex:0];
    UITextField *passwrod = [alert textFieldAtIndex:1];

    if ([title isEqualToString:@"New Profile"]) {
        if ([self checkUsernameExists:username.text] == false) {
            // Create new account
        }
        else {
            [self errorPop:@"New Profile"];
        }
    }
}
-(void) errorPop:(NSString*)who {
    if ([who isEqualToString:@"New Profile"]) {
        UIAlertView *alert3 = [[UIAlertView alloc] initWithTitle:@"OH NOOOOO"
                                                        message:@"Username is already taken please try another one."
                                                       delegate:self
                                              cancelButtonTitle:@"K."
                                              otherButtonTitles:nil];

        [alert3 show];
    }
}

日志

2014-07-30 19:57:49.594 App[6532:a0b] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'textFieldIndex (0) is outside of the bounds of the array of text fields'

Answer 1

第一个警报 View 不包含文本字段，因此当您请求 -clickedButtonAtIndex: 中的第一个或第二个文本字段时，您会遇到越界异常。

您应该区分您正在接收回调的警报 View 。尝试在创建时将警报 View 存储在属性中，然后在尝试访问文本字段之前在回调中检查它们的身份。