Question

我正在尝试使用UIImagePickerControllerSourceTypeCamera拍照。当我在快照中拍摄照片后，我得到一张空白照片，但如果我选择使用照片，我可以看到它我是我的UIImage：

enter image description here 也在控制台中我得到这些错误：

：CGAffineTransformInvert：奇异矩阵。

和

快照未呈现的视图会导致空快照。确保在屏幕更新后快照或快照之前，您的视图至少呈现过一次。

这是我的代码：

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
 }

- (void)viewDidAppear:(BOOL)animated {

  [super viewDidAppear:animated];

}

- (void)didReceiveMemoryWarning
{
  [super didReceiveMemoryWarning];
  // Dispose of any resources that can be recreated.
}

- (IBAction)takePhoto:(id)sender
{

if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
{
    UIImagePickerController *imagePicker =[[UIImagePickerController alloc] init];
    imagePicker.delegate = self;
    imagePicker.sourceType =UIImagePickerControllerSourceTypeCamera;
    imagePicker.mediaTypes = @[(NSString *) kUTTypeImage];
    imagePicker.allowsEditing = NO;
    [self presentViewController:imagePicker
                       animated:YES completion:nil];
    _newMedia = YES;
}
}


 - (IBAction)selectPhoto:(id)sender
 {

if ([UIImagePickerController isSourceTypeAvailable:
     UIImagePickerControllerSourceTypeSavedPhotosAlbum])
{
    UIImagePickerController *imagePicker =
    [[UIImagePickerController alloc] init];
    imagePicker.delegate = self;
    imagePicker.sourceType =
    UIImagePickerControllerSourceTypePhotoLibrary;
    imagePicker.mediaTypes = @[(NSString *) kUTTypeImage];
    imagePicker.allowsEditing = NO;
    [self presentViewController:imagePicker
                       animated:YES completion:nil];
    _newMedia = NO;
}

}

#pragma mark UIImagePickerControllerDelegate

-(void)imagePickerController:(UIImagePickerController *)picker
 didFinishPickingMediaWithInfo:(NSDictionary *)info
{
NSString *mediaType = info[UIImagePickerControllerMediaType];

[self dismissViewControllerAnimated:YES completion:nil];

if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
    UIImage *image = info[UIImagePickerControllerOriginalImage];

    _imageView.image = image;
    if (_newMedia)
        UIImageWriteToSavedPhotosAlbum(image,
                                       self,


  @selector(image:finishedSavingWithError:contextInfo:),
                                       nil);
}
else if ([mediaType isEqualToString:(NSString *)kUTTypeMovie])
{
    // Code here to support video if enabled
}
}

-(void)image:(UIImage *)image finishedSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
if (error) {
    UIAlertView *alert = [[UIAlertView alloc]
                          initWithTitle: @"Save failed"
                          message: @"Failed to save image"
                          delegate: nil
                          cancelButtonTitle:@"OK"
                          otherButtonTitles:nil];
    [alert show];
}
}

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

Answer 1

我测试了你的代码，它的工作正常。我认为您面临的问题与此问题有关......

快照未渲染的视图会导致空白快照。确保您的视图至少在之前呈现过一次屏幕更新后的快照或快照。

查看此帖子;这可能对你有所帮助...... UIImagePickerController error: Snapshotting a view that has not been rendered results in an empty snapshot in iOS 7

如果您遗漏了某些内容，请填写完整的代码...
的 ViewController.h

#import <UIKit/UIKit.h> @interface ViewController : UIViewController <UIImagePickerControllerDelegate, UINavigationControllerDelegate> @property (nonatomic, weak) IBOutlet UIImageView *imageView; - (IBAction)takePhoto:(id)sender; - (IBAction)selectPhoto:(id)sender; @end

ViewController.m

#import "ViewController.h" @import MobileCoreServices; @interface ViewController () @property (nonatomic, readwrite) BOOL newMedia; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view. } - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } - (IBAction)takePhoto:(id)sender { if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) { UIImagePickerController *imagePicker =[[UIImagePickerController alloc] init]; imagePicker.delegate = self; imagePicker.sourceType =UIImagePickerControllerSourceTypeCamera; imagePicker.mediaTypes = @[(NSString *) kUTTypeImage]; imagePicker.allowsEditing = NO; [self presentViewController:imagePicker animated:YES completion:nil]; _newMedia = YES; } } - (IBAction)selectPhoto:(id)sender { if ([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeSavedPhotosAlbum]) { UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init]; imagePicker.delegate = self; imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; imagePicker.mediaTypes = @[(NSString *) kUTTypeImage]; imagePicker.allowsEditing = NO; [self presentViewController:imagePicker animated:YES completion:nil]; _newMedia = NO; } } //- (IBAction)takePhoto_ #pragma mark UIImagePickerControllerDelegate -(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info { NSString *mediaType = info[UIImagePickerControllerMediaType]; [self dismissViewControllerAnimated:YES completion:nil]; if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) { UIImage *image = info[UIImagePickerControllerOriginalImage]; _imageView.image = image; if (_newMedia) UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:finishedSavingWithError:contextInfo:), nil); } else if ([mediaType isEqualToString:(NSString *)kUTTypeMovie]) { // Code here to support video if enabled } } -(void)image:(UIImage *)image finishedSavingWithError:(NSError *)error contextInfo:(void *)contextInfo { if (error) { UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"Save failed" message: @"Failed to save image" delegate: nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; } } -(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker { [self dismissViewControllerAnimated:YES completion:nil]; } @end

Answer 2

由于DevC的评论指向了正确的方向，我找到了问题的解决方案。我使用ActionSheet来显示UIImagePickerController，因此当点击其上的按钮时，动画仍会在选择器打开时运行。我在运行触发thepicker的代码之前关闭了选择器来解决它：

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex {
    [actionSheet dismissWithClickedButtonIndex:999 animated:NO]; //non-existing button index so it doesn't trigger anything again

    // Rest of code here (UIImagePickerController trigger)
}

Answer 3

我遇到了同样的问题。如果我将相机代码复制到新项目，它可以很好地工作。所以我想也许这不是代码的问题。最后，在我的项目中，我发现它是由一个关于状态栏的第三方库引起的。

    self.MTStateBar = [[[MTStatusBarOverlay alloc] initWithFrame:CGRectMake(0, 0, 320, 20)] autorelease];

我通过替换它解决了这个问题。希望这个答案可以帮到你。

Answer 4

更新3/15：您使用UIActionSheet来显示UIImagePickerController吗？我通过UIAlertController替换UIActionSheet来解决它。因为UIAlertView可能会导致意外错误。不再使用UIAlertView;）

我认为这是iOS的错误，你可以延迟0.5秒来呈现UIImagePickerController，它对我有用

UIImagePickerController摄像头空白快照图像

4 个答案: