private void ShowMedia(int taskIndex, int pathIndex)
{
Intent viewActivity = new Intent(this, typeof(MediaViewerActivity));
viewActivity.PutExtra("RES_INDEX", pathIndex);
viewActivity.PutExtra("ACT_ID", learningActivity.Id);
viewActivity.PutExtra("JSON", JsonConvert.SerializeObject(adapter.Items[taskIndex]));
adapter.Items[taskIndex].IsCompleted = true;
adapter.CheckForChildren(taskIndex);
StartActivityForResult(viewActivity, MediaPlayerReqCode);
}