CODEWITHSUNDEEP
wpfmemoryprismmefdispose
Ivan
Ivan

Reputation: 173

Memory leak with IDisposable in ViewModel, why?

Using a C#, WPF, MVVM, Prism, MEF. I need the external effects (I have it from the View is called Dispose ()) to free resources in the ViewModel, used in the View. I use something like the following code:

public class MyViewModel: IDisposable, IMyViewModel, ...
{
    private bool disposed = false;

    private System.Timers.Timer timer;

    public MyViewModel()
    {
        timer = new System.Timers.Timer();
        timer.Interval = 100;
        //timer.Elapsed += new ElapsedEventHandler(timer_Elapsed);
        timer.Start();
    }

    public void Dispose()
    {
        Dispose(true);

        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        if(!this.disposed)
        {
            if(disposing)
            {
                // Dispose managed resources.
                timer.Dispose();
                timer = null;
                //GC.KeepAlive(timer);
                //GC.Collect();
            }

            disposed = true;
        }
    }

    ~MyViewModel()
    {
        Dispose(false);
    }
}

As such, the View and ViewModel instances are not destroyed and there is a memory leak. If you delete the interface and its methods IDisposable, the View and ViewModel deleted successfully.

I using ANTS Memory Profiler. On next diagram you can see three instance, from DisposableReflecationComposablePart, but must be a one instance.

enter image description here

I can not understand what was happening. Any ideas?

Edit: I understand that my statements explain the problem is the link: http://mef.codeplex.com/wikipage?title=Parts%20Lifetime&referringTitle=Guide

in the following sentence: Thus, the container will not hold references to parts it creates unless one of the following is true:

 The part is marked as Shared
 The part implements IDisposable
 One or more imports is configured to allow recomposition

Upvotes: 2

Views: 3809

Answers (1)

Adi Lester
Adi Lester

Reputation: 25211

See my question here for answers that may help you.

I was in a similar situation and ended up using a custom interface, let's say ICleanup, instead of IDisposable in order to avoid having MEF keeping a reference to my views.

I consider this to be a very big flaw in MEF's design. I thought they would at least let each part decide for itself whether a reference to it should be kept by using a certain attribute or by implementing an interface...

Upvotes: 3

Related Questions