UIImagePickerController 相机类型返回黑色图像

Posted 2023-03-16

【中文标题】UIImagePickerController 相机类型返回黑色图像

【英文标题】：UIImagePickerController camera type returning black image

【发布时间】：2013-10-21 07:28:58

【问题描述】：

我在 UIImagePickerController 上苦苦挣扎，因为当我打开相机并拍摄图像时，它在 ios 7 中显示黑屏，因为这在 ios 6 中运行良好，我尝试了一些其他链接，但它不起作用，请帮助我解决这个问题...

我也遇到了这个错误

<Error>: CGAffineTransformInvert: singular matrix.

现在我得到了一些东西..

Snapshotting a view that has not been rendered results in an empty snapshot. Ensure your view has been rendered at least once before snapshotting or snapshot after screen updates.

当我点击拍照按钮时

 - (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
    
        dispatch_async(dispatch_get_main_queue(), ^
            if (buttonIndex == 0) 

                if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0) 

                    NSString *mediaType = AVMediaTypeVideo; // Or AVMediaTypeAudio



                AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:mediaType];

                // This status is normally not visible—the AVCaptureDevice class methods for discovering devices do not return devices the user is restricted from accessing.
                if(authStatus == AVAuthorizationStatusRestricted)
                    NSLog(@"Restricted");
                

                // The user has explicitly denied permission for media capture.
                else if(authStatus == AVAuthorizationStatusDenied)
                    NSLog(@"Denied");
                

                // The user has explicitly granted permission for media capture, or explicit user permission is not necessary for the media type in question.
                else if(authStatus == AVAuthorizationStatusAuthorized)
                    NSLog(@"Authorized");

                    if  ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
                        UIImagePickerController *imagePickerCamera =[[UIImagePickerController alloc] init];
                        imagePickerCamera.delegate = self;
                        imagePickerCamera.allowsEditing = YES;
                        imagePickerCamera.sourceType = UIImagePickerControllerSourceTypeCamera;
                        dispatch_async(dispatch_get_main_queue(), ^
                            [self presentViewController:imagePickerCamera  animated:YES completion:^];
                        );

                     else 

                        NSString *errorString = [NSString stringWithFormat:@"This device does not support this feature."];
                        UIAlertView * errorAlert = [[UIAlertView alloc] initWithTitle:@"Alert" message:errorString delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
                        [errorAlert show];
                    
                

                // Explicit user permission is required for media capture, but the user has not yet granted or denied such permission.
                else if(authStatus == AVAuthorizationStatusNotDetermined)

                    [AVCaptureDevice requestAccessForMediaType:mediaType completionHandler:^(BOOL granted) 
                        if(granted)
                            NSLog(@"Granted access to %@", mediaType);
                        
                        else 
                            NSLog(@"Not granted access to %@", mediaType);
                        
                    ];

                

                else 
                    NSLog(@"Unknown authorization status");
                
            

            else 
                if  ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
                    dispatch_async(dispatch_get_main_queue(), ^
                        UIImagePickerController *imagePickerCamera =[[UIImagePickerController alloc] init];
                    imagePickerCamera.delegate = self;
                    imagePickerCamera.mediaTypes = @[(NSString *) kUTTypeImage];
                    imagePickerCamera.allowsEditing = YES;
                    imagePickerCamera.sourceType = UIImagePickerControllerSourceTypeCamera;
                        [self presentViewController:imagePickerCamera  animated:YES completion:nil];
                    );
                 else 

                    NSString *errorString = [NSString stringWithFormat:@"This device does not support this feature."];
                    UIAlertView * errorAlert = [[UIAlertView alloc] initWithTitle:@"Alert" message:errorString delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
                    [errorAlert show];
                
            


         else if (buttonIndex == 1) 


            if  ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) 
                UIImagePickerController *imagePickerAlbum =[[UIImagePickerController alloc] init];
                imagePickerAlbum.delegate = self;
                imagePickerAlbum.mediaTypes = @[(NSString *) kUTTypeImage];
                imagePickerAlbum.allowsEditing = YES;
                imagePickerAlbum.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

                [self presentViewController:imagePickerAlbum animated:YES completion:nil];
             else 

                NSString *errorString = [NSString stringWithFormat:@"This device does not support this feature."];
                UIAlertView * errorAlert = [[UIAlertView alloc] initWithTitle:@"Alert" message:errorString delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
                [errorAlert show];
            
        
    );



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

[picker dismissModalViewControllerAnimated:YES];
_upLoadimage = info[UIImagePickerControllerEditedImage];

【问题讨论】：

当我们访问照片库但从未要求相机图像模式时，我添加了某人的提及

不，它不工作，反正我尝试了覆盖视图，它现在以某种方式工作，但仍在寻找一个体面的解决方案

【参考方案1】：

我的相机也有同样的问题。我修改或编辑相机图像的屏幕显示为黑色。日志显示了同样的错误（CGAffineTransformInvert xx）。我做了很多检查以确定或知道错误在哪里。

在我的应用程序中，我使用组件 SVProgessHUD 来显示警报和消息。使用此用法注释行可以纠正问题。我已经更新到组件的最新版本（1.0）并且错误 CGAffineTransformInvert 消失了。