WPF Performance issue with Unmanaged objects

I have developed an application in WPF with C#. The application includes a third party dll for displaying the camera in a particular window.

Normally the application takes the memory 90 MB - 135 MB without camera object (Unmanaged object). i.e I removed all the code reagrding the camera object in the design and code page (xaml and xaml.cs). The memory increasing and stops at one max value.

If I use the camera object in the application, the memory is increasing gradually. When I 开发者_如何学编程open the camera window every time, the memory will be increased gradually like 135 MB 141 MB, 143 MB....

I have used GC.Collect and the Using statement for all necessary place to clear the managed memory. I am not able to reduce or stop the memory increasing.

How to solve this issue?

Any suggestions will appreciate

Thanks in advance.

Using GC.Collect typically doesn't reduce your memory footprint. Stop calling that and you may see some improvement.

On a more general note, you shouldn't worry so much about the perceived footprint of your .NET application (especially if you're monitoring it through Task Manager!). The .NET runtime will release memory when it needs to - for example when under pressure, or when idle - and so the value you're seeing isn't necessarily indication that it's using more memory - it's just reserved memory for the time being.

One small test that can demonstrate this: what happens when you minimise your .NET app? Very often you'll see memory use in Task Manager drop dramatically, and it won't come back up immediately when you redisplay the window.

It seems you have answered your own question:

If I use the camera object in the application, the memory is increasing gradually. When I open the camera window every time, the memory will be increased gradually like 135 MB 141 MB, 143 MB....

I have used GC.Collect and the Using statement for all necessary place to clear the managed memory. I am not able to reduce or stop the memory increasing.

As stated above, GC.Collect only perform garbage collecting on managed objects, NOT unmanaged object. I assume the memory leaks comes from the camera object you used, not from the managed code. Then why bother you blame GC.Collect for high memory rises?

This is why I assumed the blame on the camera object:

Normally the application takes the memory 90 MB - 135 MB without camera object (Unmanaged object). i.e I removed all the code reagrding the camera object in the design and code page (xaml and xaml.cs). The memory increasing and stops at one max value.

If I use the camera object in the application, the memory is increasing gradually. When I open the camera window every time, the memory will be increased gradually like 135 MB 141 MB, 143 MB....

Then you should investigate the camera control you used. It's obvious, the culprit is the camera control.

Does the unmanaged camera component have a C# wrapper? If so does it implement IDisposable? Ensuring you dispose the camera object (if wrapped) will call its destructors in unmanaged code

Is the unmanaged code connected to your C# code via DLL import? If so ensure you are calling all "Close()" type methods to free memory in C#. I would advocate wrapping the camera component in your own .NET class implementing IDisposable in order to neatly package this up

Are you subscribing to any .NET events and not unsubscribing? Such as Camera.ImageReceived += new EventHandler... Leaving subscriptions to .NET events open can cause a subtle memory leak as the GC cannot collect an object while there is a reference to it (via event subscription)

Finally, a crude test to check for memory leak would be to leave your app running overnight with multiple create / delete camera window operations. See if you get an OutOfMemoryException the next day. As previous posters mentioned Task Manager is not going to report accurately the memory usage of a .NET app, however the acid test is does the GC eventually free the memory or does it keep growing indefinitely?