We are having a strange problem with UIImagePickerController. In our application, users can fill out a number of forms, as well as attach images and videos to these forms.
We allow users to add multiple photos / videos either from the camera roll or record while filling out the form.
We use the UIImagePickerController for this. The problem occurs when 1 or 2 images / videos are taken with the camera.
As soon as 1 or 2 images / videos are captured, when the camera screen is entered a third time, the image will be static and will not be updated. The view was stuck in the last frame of what was last recorded.
If the capture button is pressed, the image / video is suddenly updated and captured, as indicated by the camera. From now on, the collector is good for another, behaving normally. In addition, selecting an image / video from the camera roll to make everything behave again for another image / video. Finally, when the screen does not respond and the user selects a picture, the image will be reduced to a small rectangle within the view. The controller is configured as follows:
private void SourceChosen(EventHandler<UIImagePickerMediaPickedEventArgs> captureEvent, int buttonIndex, string[] mediaTypes)
{
var picker = ConfigurePicker(mediaTypes, captureEvent);
if (CameraAvailable && buttonIndex == 0)
{
picker.SourceType = UIImagePickerControllerSourceType.Camera;
picker.CameraDevice = UIImagePickerControllerCameraDevice.Rear;
this.NavigationController.PresentViewController(picker, true, () => { });
}
if ((!CameraAvailable && buttonIndex == 0) || (CameraAvailable && buttonIndex == 1))
{
picker.SourceType = UIImagePickerControllerSourceType.PhotoLibrary;
this.NavigationController.PresentViewController(picker, false, () => { });
}
}
private UIImagePickerController ConfigurePicker(string[] mediaTypes, EventHandler<UIImagePickerMediaPickedEventArgs> captureEvent)
{
var mediaPicker = new UIImagePickerController();
mediaPicker.FinishedPickingMedia += captureEvent;
mediaPicker.Canceled += (sender, args) => mediaPicker.DismissViewController(true, () => { });
mediaPicker.SetBarDefaults();
mediaPicker.MediaTypes = mediaTypes;
return mediaPicker;
}
An example captureEvent object is as follows:
void PhotoChosen(object sender, UIImagePickerMediaPickedEventArgs e)
{
UIImage item = e.OriginalImage;
string fileName = string.Format("{0}.{1}", Guid.NewGuid(), "png");
string path = Path.Combine(IosConstants.UserPersonalFolder, fileName);
NSData imageData = item.AsPNG();
CopyData(imageData, path, fileName, ViewModel.Images, ((UIImagePickerController)sender));
}
private void CopyData(NSData imageData, string path, string fileName, List<AssociatedItem> collectionToAddTo, UIImagePickerController picker)
{
byte[] imageBytes = new byte[imageData.Length];
System.Runtime.InteropServices.Marshal.Copy(imageData.Bytes, imageBytes, 0, Convert.ToInt32(imageData.Length));
File.WriteAllBytes(path, imageBytes);
AssociatedItem item = new AssociatedItem
{
StorageKey = fileName
};
collectionToAddTo.Add(item);
picker.DismissViewController(true, ReloadTables);
}
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public class PickerDelegate : UIImagePickerControllerDelegate
{
private readonly Action<UIImagePickerController, NSDictionary> _captureEvent;
public PickerDelegate(Action<UIImagePickerController, NSDictionary> captureEvent)
{
_captureEvent = captureEvent;
}
public override void FinishedPickingMedia(UIImagePickerController picker, NSDictionary info)
{
_captureEvent(picker, info);
}
}
,
void PhotoChosen(UIImagePickerController picker, NSDictionary info)
{
UIImage item = (UIImage)info.ObjectForKey(UIImagePickerController.OriginalImage);
string fileName = string.Format("{0}.{1}", Guid.NewGuid(), "png");
string path = Path.Combine(IosConstants.UserPersonalFolder, fileName);
NSData imageData = item.AsPNG();
CopyData(imageData, path, fileName, ViewModel.Images, picker);
}
void VideoChosen(UIImagePickerController picker, NSDictionary info)
{
var videoURL = (NSUrl)info.ObjectForKey(UIImagePickerController.MediaURL);
NSData videoData = NSData.FromUrl(videoURL);
string fileName = string.Format("{0}.{1}", Guid.NewGuid(), "mov");
string path = Path.Combine(IosConstants.UserPersonalFolder, fileName);
CopyData(videoData, path, fileName, ViewModel.Videos, picker);
}