I use a code from http://msdn.microsoft.com/en-us/library/windowsphone/develop/hh202956%28v=vs.105%29.aspx
while
I've got exception when i push back button but camera is not Initialized.
An exception of type 'System.ObjectDisposedException' occurred in Microsoft.Devices.Camera.ni.dll and wasn't handled before a managed/native boundary
How to avoid exception?
The problem with:
protected override void OnNavigatingFrom(System.Windows.Navigation.NavigatingCancelEventArgs e)
{
try
{
if (_photoCamera != null )
{
// Dispose camera to minimize power consumption and to expedite shutdown.
_photoCamera.Dispose();
_photoCamera.Initialized -= cam_Initialized;
_photoCamera.AutoFocusCompleted -= _photoCamera_AutoFocusCompleted;
}
}
catch (Exception)
{
throw;
}
}
Related
I have a loop like this inside a try-catch block:
try
{
while ((receivedBytesCount = await tcpClient.GetStream().ReadAsync(rxBytes, 0, rxBytes.Length, tcpCancellationSource.Token)) != 0)
{
// handling rxBytes[]
}
}
catch (OperationCanceledException oce)
{
Console.WriteLine($"Shutting down TCP thread...");
}
catch (Exception e)
{
// handle other exceptions
}
When I request cancel on tcpCancellationSource from somewhere:
tcpCancellationSource.Cancel();
my application throws OperationCanceledException exception, but not from try-catch block.
How should I handle that cancellation properly?
I am trying to understand exception handling in TPL Dataflow so I can effectively handle errors. In my comment numbered 1. below I am expecting to catch an AggregateException but everything just halts and doesn't recover. If I remove the throw (2.) then the ActionBlock continues to process but again, the AggregateException handler doesn't trigger.
Would anyone be able to help with an explanation to improve my intuition.
Would also welcome any documentation references on the topic.
async Task Main()
{
var ab = new System.Threading.Tasks.Dataflow.ActionBlock<int>(async a => {
try
{
await Task.Delay(100);
if (a == 7)
{
throw new Exception("Failed");
}
else
{
Console.WriteLine(a);
}
}
catch (Exception ie)
{
Console.WriteLine(ie.Message);
throw; //2. This causes the actionblock to halt, removing allows block to continue
}
});
for (int i = 0; i < 10; i++)
{
await ab.SendAsync(i);
}
ab.Complete();
try
{
await ab.Completion;
}
catch (AggregateException ae)
{
Console.WriteLine(ae.Flatten().Message);
// 1. Expecting to catch here.
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
}
What you're seeing is the await unwrapping your Aggregate Exception. When you await the completion task the exception is unwrapped and thrown to the general exception catch. But if you don't unwrap the exception then you'd see the exception caught as an aggregate exception like this:
try
{
ab.Completion.Wait();
}
catch (AggregateException ae)
{
Console.WriteLine("Aggregate Exception");
// 1. Expecting to catch here.
}
catch (Exception e)
{
Console.WriteLine("Exception Caught");
}
It's obviously better to properly await the completion but this samples shows you that indeed an AggregateExcpetion is caught when it's not unwrapped.
I'm working on WP7/8 application with barcode scanning. And have a problem with disposing camera. Camera initialize too long, and when camera is still initializing and I press back button, I've got a fatal error:
A first chance exception of type 'System.ObjectDisposedException'
occurred in Microsoft.Devices.Camera.ni.dll WinRT information: Fatal
error. Disposing capture device.
Could anybody helps me how to avoid this error?
my code:
protected override void OnNavigatedTo(NavigationEventArgs e)
{
InitializeAndGo();
base.OnNavigatedTo(e);
}
protected override void OnNavigatingFrom(System.Windows.Navigation.NavigatingCancelEventArgs e)
{
disposeCamera();
}
private void PhotoCameraOnInitialized(object sender, CameraOperationCompletedEventArgs cameraOperationCompletedEventArgs)
{
_width = Convert.ToInt32(_photoCamera.PreviewResolution.Width);
_height = Convert.ToInt32(_photoCamera.PreviewResolution.Height);
_luminance = new PhotoCameraLuminanceSource(_width, _height);
if (_photoCamera.IsFlashModeSupported(FlashMode.Auto))
{
_photoCamera.FlashMode = FlashMode.Off;
}
cameraInitialized = true;
Dispatcher.BeginInvoke(() =>
{
FlashCheckbox.IsEnabled = true;
if (_photoCamera.IsFlashModeSupported(FlashMode.Auto))
{
_photoCamera.FlashMode = FlashMode.Off;
}
});
_photoCamera.Focus();
}
private void InitializeAndGo()
{
stopScan = false;
_photoCamera = new PhotoCamera();
_photoCamera.Initialized += PhotoCameraOnInitialized;
_photoCamera.AutoFocusCompleted += PhotoCameraOnAutoFocusCompleted;
viewfinderBrush.SetSource(_photoCamera);
_previewTransform.Rotation = _photoCamera.Orientation;
_results = new ObservableCollection<Result>();
_barcodeReader = new BarcodeReader();
_barcodeReader.TryHarder = true;
_barcodeReader.AutoRotate = true;
_service = new MyMoviesDataService(ErrorDataService);
}
private void disposeCamera()
{
try
{
cameraInitialized = false;
StopScan();
_photoCamera.Initialized -= PhotoCameraOnInitialized;
_photoCamera.AutoFocusCompleted -= PhotoCameraOnAutoFocusCompleted;
_photoCamera.Dispose();
_photoCamera = null;
}
catch (Exception ex)
{
App.ShowErrorToast(ex.Message);
}
}
Don't use the camera until it's been successfully initialized (You can check this in the camera's Initialized event).
Also, wrap any usages of the camera in a
try
{
// camera code here
}
catch (ObjectDisposedException)
{
// re-initialize the camera?
}
to handle situations like suspension, which will dispose of the camera automatically.
As for the
An exception of type 'System.ObjectDisposedException' occurred in
Microsoft.Devices.Camera.ni.dll and wasn't handled before a
managed/native boundary WinRT information: Fatal error. Disposing
capture device.
This is something Microsoft needs to fix; I mean, how are you supposed to handle a native code exception if it isn't allowed to propagate to managed code?
Where is the exception coming from (which code line / block)?
I would for starter put a try...catch around InitializeAndGo() in the OnNavigatedTo event handler. And on the whole PhotoCameraOnInitialized event handler also.
Cheers,
once again I need some help:
yesterday I asked this question that was about the way to use a large jpg image as a Bitmap (http://stackoverflow.com/questions/13511657/problems-with-big-drawable-jpg-image) and I resolved myself (Is my own response on that question) but whenever I resume my activity, as it uses that bitmap as the GLRenderer texture it crashes. I've tried many things, the last try was to make that bitmap static in order to keep it as a member variable into the activity but it crashes because, I supose, it looses it's mBuffer.
More details on the Activity code:
I declared it as SingletonInstance into the manifest:
android:launchMode="singleInstance"
in order to keep the tiles for the renderer.
and here some code:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mGLSurfaceView = new GLSurfaceView(this);
mGLSurfaceView.setEGLConfigChooser(true);
mSimpleRenderer = new GLRenderer(this);
getTextures();
if (!mIsTileMapInitialized){
tileMap = new LandSquareGrid(1, 1, mHeightmap, mLightmap, false, true, true, 128, true);
tileMap.setupSkybox(mSkyboxBitmap, true);
mIsTileMapInitialized = true;
}
initializeRenderer();
mGLSurfaceView.setRenderer(mSimpleRenderer);
setContentView( R.layout.game_layout );
setOnTouchListener();
initializeGestureDetector();
myCompassView = (MyCompassView)findViewById(R.id.mycompassview);
// Once set the content view we can set the TextViews:
coordinatesText = (TextView) findViewById(R.id.coordDynamicText);
altitudeText = (TextView) findViewById(R.id.altDynamicText);
directionText = (TextView) findViewById(R.id.dirDynamicText);
//if (!mIsGLInitialized){
mOpenGLLayout = (LinearLayout)findViewById(R.id.openGLLayout);
mOpenGLLayout.addView(mGLSurfaceView);
mVirtual3DMap = new Virtual3DMap(mSimpleRenderer, tileMap);
if (mGameThread == null){
mGameThread = new Thread(mVirtual3DMap);
mGameThread.start();
}
}
On getTextures method I get few small textures and the largest one as in my last question self response:
if (mTerrainBitmap==null){
InputStream is = getResources().openRawResource(R.drawable.terrain);
try {
// Set terrain bitmap options to 16-bit, 565 format.
terrainBitmapOptions.inPreferredConfig = Bitmap.Config.RGB_565;
Bitmap auxBitmap = BitmapFactory.decodeStream(is, null, terrainBitmapOptions);
mTerrainBitmap = Bitmap.createBitmap(auxBitmap);
}
catch (Exception e){
}
finally {
try {
is.close();
}
catch (IOException e) {
// Ignore.
}
}
}
So, again, first time it works great but when I go back I do:
protected void onPause() {
super.onPause();
mGLSurfaceView.onPause();
}
#Override
protected void onStop() {
// TODO Auto-generated method stub
super.onStop();
if (mVirtual3DMap != null) {
try {
mVirtual3DMap.cancel();
mGameThread=null;
mVirtual3DMap = null;
mGLSurfaceView.destroyDrawingCache();
mSimpleRenderer=null;
System.gc();
} catch (Throwable e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
And whan I resume the activity:
#Override
protected void onResume() {
super.onResume();
mGLSurfaceView.onResume();
if (mVirtual3DMap != null) {
try {
mVirtual3DMap.resume();
} catch (Throwable e) {
e.printStackTrace();
}
}
}
And it crashes.
Why?? Ok, here is the exception cause on the GLThread:
java.lang.IllegalArgumentException: bitmap is recycled...
I tried this messy stuff because launching more than two times the original activity the application crashes bacuse of this or because of the amount of memory used and now I don't know if revert all these changes or what todo with this.
Is there a good way to keep in memory and usable, by this or another application activity, this bitmap?
Please, I need your advices.
Thanks in advance.
Do not handle resources manually or your app's surface will broke up. You can't handle your resources manually.
If you worry about reloading resources and you use API level 11+, you can use setPreserveEGLContextOnPause(). It will perserve your textures and FBOs.
If you can't use API 11+, you can port GLSurfaceView() to your app. You can check my own GLSurfaceView that is ported from ICS.
PS: Sorry about my poor english.
No. Let Android handle all the resources. You must handle the appropriate events and reload the bitmap when the activity is resumed. You cannot expect, that any OpenGL handles are still valid after the activity has been resumed.
Think of it as in the example of a laptop coming out from hibernation. Although all memory has been restored, you cannot expect that any open socket has still a real active connection going.
I am an Android noobie, so please correct me if I am wrong.
We are using MdbgCore.dll to evaluate a property off a parameter on a thread callstack.
To do this, we are performing a func-eval.
Unfortunately, all our attempts to perform the func-eval are failing with CORDBG_E_ILLEGAL_IN_OPTIMIZED_CODE, which seems to be due to the thread being used for the func-eval not being in a GC-safe point.
This is documented here: http://blogs.msdn.com/b/jmstall/archive/2005/11/15/funceval-rules.aspx.
We tried scanning all threads in the process to find a thread that is in a GC-safe point, but they all appear to have UserState marked with USER_UNSAFE_POINT.
There is very scarce documentation on the subject, and we are pulling our hair out trying to figure out if there is a way to get a thread in a GC-safe point so we can do the func-eval. We would consider anything that allows us to deterministically break into the process with a thread to do the func-eval with.
Disclaimer: we are trying to evaluate a method on a class that resides in an optimized assembly, so not sure if this is maybe also causing an issue.
The sample code follows:
if (argument.TypeName.EndsWith(
"WorkerRequest", StringComparison.OrdinalIgnoreCase)
&& !argument.IsNull)
{
try
{
// Invoke the "GetUriPath()" function to obtain the URI
string functionName = "System.Web.HttpWorkerRequest.GetUriPath";
MDbgFunction func = debugger.Processes.Active.ResolveFunctionNameFromScope(
functionName,
thread.CorThread.AppDomain
);
if (null == func)
{
throw new InvalidOperationException(
String.Format("Could not resolve {0}", functionName));
}
// Setup the eval
CorEval eval = threadForFuncEvals.CorThread.CreateEval();
// Setup the function parameters
List<CorValue> values = new List<CorValue>();
// Add the worker request "this" pointer
values.Add(
argument.CorValue
);
// resume the thread being used to do the func-eval
threadForFuncEvals.CorThread.DebugState = CorDebugThreadState.THREAD_RUN;
// Queue the function for execution
// EXCEPTION THROWN BELOW
// EXCEPTION THROWN BELOW
// EXCEPTION THROWN BELOW
eval.CallFunction(func.CorFunction, values.ToArray());
// BUGBUG: Should we pause all other threads to prevent them from moving?
// Continue the process to execute the function
if (!proc.Go().WaitOne(settings.BreakTimeout))
{
throw new InvalidOperationException("Timeout while evaluating function");
}
// get the returned string
var result = eval.Result;
if (result != null)
{
MDbgValue mv = new MDbgValue(proc, result);
string returnedValue = mv.GetStringValue(false);
threadInfo.Url = returnedValue;
}
}
catch (Exception e)
{
// BUGBUG: Ignoring exception
}
finally
{
// suspend the thread again
if (threadForFuncEvals != null)
{
threadForFuncEvals.CorThread.DebugState =
CorDebugThreadState.THREAD_SUSPEND;
}
}
}
Microsoft / Mdbg team, can you help?
Best,
Mike
Is this something to do with JIT optimization?
In my program, I turn JIT optimization off (for technical reasons, I think you can only do this with CreateProcess() and not using Attach()).
proc = m_Debugger.CreateProcess(ProcessName, ProcessArgs, DebugModeFlag.Default, DebugEngineUtils.GetAssemblyRuntimeVersion(ProcessName,DefaultNetVersion));
if (proc!=null) proc.CorProcess.OnCreateProcess += new Microsoft.Samples.Debugging.CorDebug.CorProcessEventHandler(CorProcess_OnCreateProcess);
if (proc!=null) proc.CorProcess.OnModuleLoad += new Microsoft.Samples.Debugging.CorDebug.CorModuleEventHandler(CorProcess_OnModuleLoad);
void CorProcess_OnModuleLoad(object sender, Microsoft.Samples.Debugging.CorDebug.CorModuleEventArgs e)
{
e.Module.JITCompilerFlags = Microsoft.Samples.Debugging.CorDebug.CorDebugJITCompilerFlags.CORDEBUG_JIT_DISABLE_OPTIMIZATION;
}
void CorProcess_OnCreateProcess(object sender, Microsoft.Samples.Debugging.CorDebug.CorProcessEventArgs e)
{
//try to disable optimization
((Microsoft.Samples.Debugging.CorDebug.CorProcess)sender).DesiredNGENCompilerFlags = Microsoft.Samples.Debugging.CorDebug.CorDebugJITCompilerFlags.CORDEBUG_JIT_DISABLE_OPTIMIZATION;
}