PhotoCamera issue while Initialization

Question

I am developing windows phone 8 app which use PhotoCamera for capturing image. I am getting issue when I press screen lock key. My PhotoCamera object not disposing when I press lock key. I am getting the problem when I press screen lock key at the time of Camera Initialization.

Here is some code.

Button click code

_photoCamera = new PhotoCamera();
_photoCamera.Initialized += OnPhotoCameraInitialized;
_photoCamera.CaptureImageAvailable += new EventHandler<Microsoft.Devices.ContentReadyEventArgs>(cam_CaptureImageAvailable);
_photoCamera.AutoFocusCompleted += new EventHandler<CameraOperationCompletedEventArgs>(cam_AutoFocusCompleted);

_previewTransform.Rotation = _photoCamera.Orientation;
_previewVideo.SetSource(_photoCamera);

Here is my OnPhotoCameraInitialized code

 private void OnPhotoCameraInitialized(object sender, CameraOperationCompletedEventArgs e)
 {
        try
        {
            Dispatcher.BeginInvoke(() =>
            {
                gvCamera.Visibility = Visibility.Visible;
                gvCameraImage.Visibility = Visibility.Collapsed;
                Cancel.Visibility = Visibility.Visible;
                imgScanCancle.Visibility = Visibility.Visible;
            });
            cameraInit = true;
            _photoCamera.FlashMode = FlashMode.Auto;
            _photoCamera.Focus();
        }
        catch (Exception ex)
        {
            //MessageBox.Show(ex.Message);
        }
 }

Here is my NavigationFrom code

protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)
{
        base.OnNavigatedFrom(e);
        try
        {
            if (cameraInit)
            {
                if (_photoCamera != null)
                {
                    _photoCamera.Dispose();
                    _photoCamera.Initialized -= OnPhotoCameraInitialized;
                    _photoCamera.CaptureImageAvailable -= cam_CaptureImageAvailable;
                    _photoCamera.AutoFocusCompleted -= cam_AutoFocusCompleted;
                    _photoCamera = null;
                    cameraInit = false;
                }
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
 }

I have re-Initialized photocamera in OnNavigatedTo Method

Here is OnNavigatedTo code.

            if (GlobalSettings.IspreservedState)
            {
                if (!GlobalSettings.istest_performed)
                {                        
                    if (_photoCamera == null)
                    {
                        _nbTry = 0;

                        _photoCamera = new PhotoCamera();
                        _photoCamera.Initialized += OnPhotoCameraInitialized;
                        _photoCamera.CaptureImageAvailable += new EventHandler<Microsoft.Devices.ContentReadyEventArgs>(cam_CaptureImageAvailable);
                        _photoCamera.AutoFocusCompleted += new EventHandler<CameraOperationCompletedEventArgs>(cam_AutoFocusCompleted);

                        _previewTransform.Rotation = _photoCamera.Orientation;
                        _previewVideo.SetSource(_photoCamera);
                    }
                }
            }

Basically what I am trying to do is Capture the picture and display it. I have a problem when I press a lock key before camera Initialization. When I press lock key, OnNavigatedFrom code start executing. When it reach to if(cameraInit) inside code not executed because cameraInit not true. I have set cameraInit = true; in OnPhotoCameraInitialized method. But unfortunately this code block not execute. so my question is How can I dispose camera object? I can dispose it only when it is fully Initialized. But I press lock key before Initialization. Is there any way to clean the video brush?

Answer 1

Hello to all my problem is solved.

I have changed code in OnNavigatedFrom and OnPhotoCameraInitialized.

Here is code OnNavigatedFrom

            if (cameraInit)
            {
                Dispatcher.BeginInvoke(() =>
                {
                    if (_photoCamera != null)
                    {
                        _photoCamera.Dispose();
                        _photoCamera.Initialized -= OnPhotoCameraInitialized;
                        _photoCamera.CaptureImageAvailable -= cam_CaptureImageAvailable;
                        _photoCamera.AutoFocusCompleted -= cam_AutoFocusCompleted;
                        _photoCamera = null;
                        cameraInit = false;
                    }
                });
            }

Here is my OnPhotoCameraInitialized

            if (e.Succeeded)
            {
                cameraInit = true;

                Dispatcher.BeginInvoke(() =>
                {
                    gvCamera.Visibility = Visibility.Visible;
                    gvCameraImage.Visibility = Visibility.Collapsed;
                    Cancel.Visibility = Visibility.Visible;
                    imgScanCancle.Visibility = Visibility.Visible;

                    if (cameraInit)
                    {
                        _photoCamera.FlashMode = FlashMode.Auto;
                        _photoCamera.Focus();
                    }
                });
            }

Here When I press screen lock key before Initialization first thing I did i.e. I fully Initialized camera and then I dispose it. Now all working fine.