ios - PresentViewController 使我的应用程序崩溃

Question

当我尝试从 UIAlertview 按钮显示视图控制器时，我遇到了一个非常奇怪的错误。它在 prsentViewController 行上崩溃了。Backtrace 显示它无法加载视图。我怎样才能解决这个问题？源代码如下：

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    if (alertView == _alertView) {
        switch (buttonIndex) {
            case 0:
            {
                [alertView dismissWithClickedButtonIndex:buttonIndex animated:YES];
            }

                break;

            default:
            {
                NSString *nibName = IS_IPAD? NSStringFromClass([UINewUserAccountViewController class]) : [NSStringFromClass([UINewUserAccountViewController class]) stringByAppendingString:@"~iPhone"];
                UINewUserAccountViewController *newUserAccountViewController = [[UINewUserAccountViewController alloc] initWithNibName:nibName  bundle:nil];
                newUserAccountViewController.delegate = self;

                UINavigationController *navi = [[UINavigationController alloc] initWithRootViewController:newUserAccountViewController];
                [self presentViewController:navi animated:YES completion:nil];

            }
                break;
        }
    }

}

Answer 1

在@rckoenes 的帮助下，我在遇到异常几次后终于找到了错误。它停在 UIViewController loadFromNibName 因为该行

[NSStringFromClass([UINewUserAccountViewController class]) stringByAppendingString:@"~iPhone"]

返回一个 nib 名称，但在具有该名称的 xib 文件中，根视图不是文件出口。在我将视图链接到文件出口后，异常消失了。