Added some more null checks and error catching around cleaning up of …

…the camera for Windows Phone. This should fix Redth#82
MarcinPrymas · Jan 28, 2014 · ce69826 · ce69826
1 parent d10fcb0
commit ce69826
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Showing 3 changed files with 18 additions and 6 deletions.
diff --git a/src/ZXing.Net.Mobile/WindowsPhone/ScanPage.xaml.cs b/src/ZXing.Net.Mobile/WindowsPhone/ScanPage.xaml.cs
@@ -106,7 +106,8 @@ protected override void OnNavigatedTo(NavigationEventArgs e)
 
         protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
         {
-            scannerControl.StopScanning();
+            try { scannerControl.StopScanning(); }
+            catch (Exception ex) { }
 
             base.OnNavigatingFrom(e);
         }

diff --git a/src/ZXing.Net.Mobile/WindowsPhone/SimpleCameraReader.cs b/src/ZXing.Net.Mobile/WindowsPhone/SimpleCameraReader.cs
@@ -210,6 +210,7 @@ public void Stop()
 
 			if (_photoCamera != null)
 			{
+                _photoCamera.Initialized -= OnPhotoCameraInitialized;
 				_photoCamera.Dispose();
 				_photoCamera = null;
 			}
@@ -222,6 +223,9 @@ public void ShutterHalfPressed()
 
 		private void OnPhotoCameraInitialized(object sender, CameraOperationCompletedEventArgs e)
 		{
+            if (_photoCamera == null)
+                return;
+
 			var width = Convert.ToInt32(_photoCamera.PreviewResolution.Width);
 			var height = Convert.ToInt32(_photoCamera.PreviewResolution.Height);
 

diff --git a/src/ZXing.Net.Mobile/WindowsPhone/ZXingScannerControl.xaml.cs b/src/ZXing.Net.Mobile/WindowsPhone/ZXingScannerControl.xaml.cs
@@ -108,13 +108,20 @@ public void Cancel()
         private void ReaderOnCameraInitialized(object sender, bool initialized)
         {
             // We dispatch (invoke) to avoid access exceptions
-            Dispatcher.BeginInvoke(() => _previewTransform.Rotation = _reader.CameraOrientation);
+            Dispatcher.BeginInvoke(() =>
+            {
+                if (_reader != null && _previewTransform != null)
+                    _previewTransform.Rotation = _reader.CameraOrientation;
+            });
 
-            // We can set if Camera should flash or not when focused
-			_reader.FlashMode = FlashMode.Off;
+            if (_reader != null)
+            {
+                // We can set if Camera should flash or not when focused
+                _reader.FlashMode = FlashMode.Off;
 
-            // Starts the capturing process
-            _reader.Start();
+                // Starts the capturing process
+                _reader.Start();
+            }
         }
 
         private void DisplayResult(Result result)