objective-c - 没有任何按钮的 UIAlertView

Question

我想知道下面的代码是否可以。我试图在 2 秒后(并且 alertView 中没有任何按钮)从“timedAlert”方法自动关闭 alertView。

    //this is in another method  
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:@"Login successful." delegate:self cancelButtonTitle:nil otherButtonTitles:nil];
    [alert show];
    [alert release];
    [self timedAlert];
}

-(void)timedAlert
{
    [self performSelector:@selector(dismissAlert:) withObject:alert afterDelay:2];
}

-(void)dismissAlert:(UIAlertView *) alertView
{
    [alertView dismissWithClickedButtonIndex:nil animated:YES];
}

如果 alertView 的 cancelButton 设置为“nil”，“[alertView dismissWithClickedButtonIndex:0 animated:YES];”将如何处理？事情的工作？？？我尝试将 cancelButton 设置为“nil”并且它起作用了，但无法弄清楚如何......

P.S: 我从另一个调用 timedAlert 方法

感谢任何帮助!谢谢!

Answer 1

首先让我说如果你用自定义 View 处理这个会更好，但话虽如此，问题看起来出在

[alert release];

您在使用完对象之前就释放了它(我很惊讶它没有崩溃)。

做这样的事情

// other code
alert = [[UIAlertView alloc] initWithTitle:nil message:@"Login successful." delegate:self cancelButtonTitle:nil otherButtonTitles:nil];
    [alert show];
    [self performSelector:@selector(dismissAlert:) withObject:alert afterDelay:3.0f];
}

-(void)dismissAlert:(UIAlertView *) alertView
{
    [alertView dismissWithClickedButtonIndex:nil animated:YES];
    [alertView release];
}