在拍摄图像并在UIImagePickerController中点击“USE”后，会随机出现黑屏

Question

我有一个应用程序已经差不多完成了，现在在QA下，QA工程师遇到了一个随机问题，在UIImagePickerController视图中点击USE后会出现黑屏。此外，在didFinishPickingMediaWithInfo中，图片正在保存以供将来重新显示，并且正在UIImageView中显示，我还使用相机覆盖来为UIImagePickerView添加按钮以及最大内存使用量该应用程序不超过 13 MB 。从捕获模式切换到相机胶卷模式时不会出现此问题。同样在同一视图iADs中也有呈现。下面是问题可能涉及的代码，也附加了图像以了解问题。任何帮助将不胜感激。

提前致谢。

(void) launchCamera 
{
     // Set up the camera\
     CustomCameraView *cameraController   = [[CustomCameraView alloc] init];  
     cameraController.sourceType          = UIImagePickerControllerSourceTypeCamera;
     cameraController.delegate            = self; 
     cameraController.showsCameraControls = YES;
     cameraController.navigationBarHidden = YES;
     cameraController.toolbarHidden       = YES;

     // overlay on top of camera lens view

     UIButton *cameraRoll = [[UIButton alloc] initWithFrame:CGRectMake(15, 380, 40, 40)];
     [cameraRoll setAlpha:0.0f];
     [cameraRoll setBackgroundImage:[UIImage imageNamed:@"CamerRoll_New"] forState:UIControlStateNormal];
     [cameraRoll addTarget:self action:@selector(switchToCameraRoll) forControlEvents:UIControlEventTouchUpInside];
     cameraController.cameraOverlayView = cameraRoll;

     [UIView beginAnimations:nil context:NULL];
     [UIView setAnimationDelay:1.5f];
     cameraRoll.alpha = 1.0f;
     [UIView commitAnimations];

     [self presentModalViewController:cameraController animated:YES];

 }

-(void)switchToCameraRoll
{
    DLog(@"Camera Roll");  
    [self dismissViewControllerAnimated:NO completion:^(void){ [self photoSourcePhotoAlbum];}];
}

-(void) photoSourcePhotoAlbum
{
     UIImagePickerController * picker = [[UIImagePickerController alloc] init];
     picker.delegate = self;
     picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
     [self presentModalViewController:picker animated:YES];
}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 
{    
    [self.view addSubview:progressView];
    timer = [NSTimer scheduledTimerWithTimeInterval:.017 target:self selector:@selector(progressChange) userInfo:nil repeats:YES];
    [picker dismissModalViewControllerAnimated:YES];
    [self performSelectorInBackground:@selector(saveImage:) withObject:info];
    [self performSelector:@selector(navigateToEditView) withObject:nil afterDelay:2.1];
}

-(void)navigateToEditView
{
    [self performSegueWithIdentifier:@"presentRDetailModalViewController" sender:self];   
}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    if (picker.sourceType == UIImagePickerControllerSourceTypeSavedPhotosAlbum) 
    {
        [picker dismissViewControllerAnimated:NO completion:^(void){ [self photoSourceCamera];}];
    }
    else 
    {
        [picker dismissModalViewControllerAnimated:YES]; 
    }
}

-(void)saveImage:(NSDictionary *)info
{    
    NSString *imageName = [[[DataStaging dataStaging] getGUID] stringByAppendingString:@".jpg"];
    rImageName = imageName;
    UIImage *rImage = [info objectForKey:@"UIImagePickerControllerOriginalImage"];

    //Compress image

    [[FileOperations fileOperations] PersistData:UIImageJPEGRepresentation(rImage, 0.4) name:imageName];
    DLog(@"%@",[[FileOperations fileOperations] fetchPath:imageName]);

    //Actual image taken

    [[self rImageView] setImage:[info objectForKey:@"UIImagePickerControllerOriginalImage"]];

    if ([rImageName length] == 0) 
    {
        [[self rDetails] setHidden:YES];
        [[self trashRImage]   setHidden:YES];
    }
    else 
    {
        [[self rDetails] setHidden:NO];

        [[self trashRImage]   setHidden:NO];
    }

    [progressView removeFromSuperview];
  }
}

Answer 1

确保在dismissModalViewControllerAnimated之前不调用presentModalViewController：animated：两次： 它对我有帮助。

- (void)showImagePickerForSourceType:(UIImagePickerControllerSourceType)sourceType
{
    if (_imagePickerController!=nil || _imagePopoverController!=nil) {
        return;
    }
    _imagePickerController = [[[UIImagePickerController alloc] init] autorelease];
    _imagePickerController.modalPresentationStyle = UIModalPresentationCurrentContext;
    _imagePickerController.sourceType = sourceType;
    _imagePickerController.delegate = self;
    switch (sourceType) {
        case UIImagePickerControllerSourceTypeCamera:
            _imagePickerController.showsCameraControls = YES;
            [self presentViewController:_imagePickerController animated:YES completion:nil];
            break;
        default:
            _imagePopoverController = [[UIPopoverController alloc] initWithContentViewController:_imagePickerController];
            _imagePopoverController.delegate = self;
            CGRect rect = [[UIScreen mainScreen] bounds];
            rect.origin.y = rect.size.height - 70.0;
            rect.size.height -= rect.origin.y;
            [_imagePopoverController presentPopoverFromRect:rect inView:self.view permittedArrowDirections:UIPopoverArrowDirectionDown animated:YES];
            break;
    }
}

- (void)imagePickerControllerDidCancel:(UIImagePickerController*)picker
{
    [_imagePopoverController dismissPopoverAnimated:YES];
    _imagePopoverController = nil;
    [_imagePickerController dismissViewControllerAnimated:YES completion:nil];
    _imagePickerController = nil;
}

- (void)imagePickerController:(UIImagePickerController*)picker didFinishPickingMediaWithInfo:(NSDictionary*)info
{
    UIImageWriteToSavedPhotosAlbum([info objectForKey:UIImagePickerControllerOriginalImage],nil,nil,nil);
    _currentImage = [info objectForKey:UIImagePickerControllerOriginalImage];

    [_imagePopoverController dismissPopoverAnimated:YES];
    _imagePopoverController = nil;
    [_imagePickerController dismissViewControllerAnimated:YES completion:nil];
    _imagePickerController = nil;
}