ios - 关闭一个 View Controller 并在完成后打开另一个，出现错误

Question

我处理了一些照片，完成后，我调用以下函数来显示输出 UI。我需要确保当前的捕获 View Controller 被关闭并且不希望它在后台运行。我使用的函数是这样的:

-(void)openOutputUIWithImage:(UIImage*)displayImage{ //update UI with new viewcontroller with specified image to display
    UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    outputView = [mainStoryboard instantiateViewControllerWithIdentifier:@"OutputView"];
    outputView.img = displayImage;
    [self dismissViewControllerAnimated:NO completion:^{
        [self presentViewController:outputView animated:YES completion:^{
            NSLog(@"output view opened!");
        }];
    }];
}

但我收到以下错误:

Warning: Attempt to present <OutputViewController: 0x100858af0> on <CircleDetectionViewController: 0x100857c20> whose view is not in the window hierarchy!

我真的不确定我做错了什么，我没有太多使用多个 View Controller 的经验。它似乎在我的另一个 View Controller 中命中了我的 viewDidLoad 方法，但只显示一个空白屏幕。任何帮助将非常感激!提前致谢!

Answer 1

这个有效:

UIViewController* presentingViewController = self.presentingViewController;
    [self dismissViewControllerAnimated:YES completion:^{
        [presentingViewController presentViewController:outputView animated:YES completion:nil];

    }];

引用了这个答案:https://stackoverflow.com/a/33058529/5071756