ios - UIAlertView 没有响应按钮事件

Question

第一次使用 UIAlertViews 时，我不明白为什么它不起作用。当我单击任一按钮时，警报关闭，但没有 NSLog 输出。我究竟做错了什么？我想不通。谢谢!

.h

@interface LoginViewController : UIViewController <UIAlertViewDelegate>

@end

.m

- (IBAction)resetPassword:(UIButton *)sender {

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Password Reset"
                                                      message:@"A temporary password will be sent to you at the address we have on file."
                                                     delegate:nil
                                            cancelButtonTitle:@"Cancel"
                                        otherButtonTitles:@"Reset Password", nil];
    [alert show];

}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    if (buttonIndex == 0) NSLog(@"button 0");
    if (buttonIndex == 1) NSLog(@"button 1");
}

Answer 1

看来您从未在 UIAlertView 上设置委托(delegate)。应该是:

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Password Reset"
                                                  message:@"A temporary password will be sent to you at the address we have on file."
                                                 delegate:self
                                        cancelButtonTitle:@"Cancel"
                                    otherButtonTitles:@"Reset Password", nil];

这样 UIAlertView 就可以在用户点击按钮时调用您的方法，- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex。