使用 NSAlert 处理按下哪个按钮的正确方法是什么

Question

我在NSAlert 对象中添加了两个按钮，目前按钮一个的返回码是1001，而按钮默认为1000。我需要有效地确定在不使用幻数的情况下按下了给定警报中的哪个按钮。否则会变得一团糟。

-(void)showErrorMessage:(NSString*)errorMessage{
    NSAlert *alert = [[NSAlert alloc] init];
    [alert setMessageText:@"Error"];
    [alert setInformativeText:errorMessage];
    [alert setAlertStyle:NSCriticalAlertStyle];
    [alert addButtonWithTitle:@"Retake test"];
    [alert addButtonWithTitle:@"Cancel test"];
    [alert beginSheetModalForWindow:window modalDelegate:self didEndSelector:@selector(retakeFingerPrintAlert:returnCode:contextInfo:) contextInfo:nil];
}

- (void)retakeTestAlert:(NSAlert *)alert
                    returnCode:(int)returnCode
                   contextInfo:(void *)contextInfo{
    NSLog(@"clicked %d button\n", returnCode);


    //I want to determine very clearly which button is being pressed in the NSAlert
    //I dont want to work with magic numbers

    //And thus call the below method dependng on the button clicked
    [self onRetakeTest];
}

Answer 1

According to Apple's documentation on "addButtonWithTitle:", which you're using:

前三个按钮的位置标识为 NSAlertFirstButtonReturn, NSAlertSecondButtonReturn, 返回码参数中的 NSAlertThirdButtonReturn 由 模态代表。后续按钮被标识为 NSAlertThirdButtonReturn +n，其中 n 为整数

所以第一个按钮应该等于 [NSAlertFirstButtonReturn]，即“1000”。第四个按钮应该是“1003”。

到目前为止还有意义吗？