App resume fail with MediaCapture WP8.1

Question

Hi everyone,
Which is the good place to initialize MediaCapture? I used Panorama theme to create a TorchControl and on itemPanorama_Loaded I set:
MediaCapture mc = new MediaCapture();
await mc.InitializeAsync();
mc.Failed += new MediaCaptureFailedEventHandler(Failed)
When App start, nothing happen but if I use other apps and resume, it keep loading, then MediaCaptureFailedEventHandler throw error out about access cross-thread.
If I tried to move code to button event then it fail to create MediaCapture on 2nd tap
Any suggestion? Thank you

Answer 1

Another finding : Keeping this MediaCapture initializing code inside the page event handlers might be an issue.I removed the async & await from Loaded / OnNavigatedTo event & the app resumed immediately but if the async await code is executed on
these handlers then the app remains on that 'resuming' window for an infinite time.
Suggestion : you can probably move the initializing code when user tries to capture the the picture and keep only one instance of it throughout and then check subsequently on each button click if its null, if it is then only create a new object otherwise
not. You can declare a variable MediaCapture _mc at the top of page for this, to have its visibility throughout the page.
http://developer.nokia.com/community/wiki/Using_Crypto%2B%2B_library_with_Windows_Phone_8
Again, I actually did it the same as your suggestion before also. App resume normally but if the button event is raised (MediaCapture is created) then app can not be resumed