UIImagePickerController 不会取消，收到有关分离的 ViewControllers 的消息

Posted 2023-03-12

【中文标题】UIImagePickerController 不会取消，收到有关分离的 ViewControllers 的消息

【英文标题】：UIImagePickerController won't cancel, getting message about detached ViewControllers

【发布时间】：2014-06-13 21:02:14

【问题描述】：

我还没有看到这两个问题混在一起，所以我想我会问。

PhotoViewController

-(void)viewDidAppear:(BOOL)animated


    UIImagePickerController *picker = [[UIImagePickerController alloc]init];
    picker.delegate = self;

    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
        picker.sourceType = UIImagePickerControllerSourceTypeCamera;
    
    else if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeSavedPhotosAlbum])
        picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
    

    [self presentViewController:picker animated:YES completion:NULL];




-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info


    UIImage *image = info[UIImagePickerControllerEditedImage];
    if(!image) image = info[UIImagePickerControllerOriginalImage];

    picker.delegate = self;

    [self setPhotoForNextVC:image];

    [self dismissViewControllerAnimated:YES completion:nil];
    [self performSegueWithIdentifier:@"givePhotoToGiveDetailsSegue" sender:self];




- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker 
    [self dismissViewControllerAnimated:YES completion:nil];

选择照片有效，但是当我按下取消时，UIImagePickerController 不断恢复，并且出现错误：

Presenting view controllers on detached view controllers is discouraged <UINavigationController: 0x10b38b560>.

【问题讨论】：

Warning :-Presenting view controllers on detached view controllers is discouraged的可能重复

【参考方案1】：

我以前也遇到过这个问题。

对我来说，事实证明是这样，尤其是在 ViewDidAppear 中。 操作系统不喜欢在另一个控制器出现后立即安装新控制器。

制作另一种处理此问题的方法。

(void)bringUpCameraController

UIImagePickerController *picker = [[UIImagePickerController alloc]init]; picker.delegate = self;

if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
    picker.sourceType = UIImagePickerControllerSourceTypeCamera;

else if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeSavedPhotosAlbum])
    picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;


[self presentViewController:picker animated:YES completion:NULL];

我的解决方法：[self performSelector: withObject: afterDelay:]

这将删除消息。

【讨论】：

所以你编写启动相机方法而不是在 viewDidAppear 中执行最后一段代码（自我执行选择器）？

是的，在 viewdidAppear 中。像这样 -(void)viewDidAppear [self performSelector :showCamera withDelay:2.0];

【参考方案2】：

在树中查找 PhotoViewController 的层次结构。应该不是根吧。我发生了这种情况。 错误消息是字面的。