.net 如何将 UI Dispatcher 传递给 ViewModel

我使用接口IContext抽象了调度器:

public interface IContext
{
   bool IsSynchronized { get; }
   void Invoke(Action action);
   void BeginInvoke(Action action);
}

This has the advantage that you can unit-test your ViewModels more easily.
I inject the interface into my ViewModels using the MEF (Managed Extensibility Framework). Another possibility would be a constructor argument. However, I like the injection using MEF more.

Update (example from pastebin link in comments):个

public sealed class WpfContext : IContext
{
    private readonly Dispatcher _dispatcher;

    public bool IsSynchronized
    {
        get
        {
            return this._dispatcher.Thread == Thread.CurrentThread;
        }
    }

    public WpfContext() : this(Dispatcher.CurrentDispatcher)
    {
    }

    public WpfContext(Dispatcher dispatcher)
    {
        Debug.Assert(dispatcher != null);

        this._dispatcher = dispatcher;
    }

    public void Invoke(Action action)
    {
        Debug.Assert(action != null);

        this._dispatcher.Invoke(action);
    }

    public void BeginInvoke(Action action)
    {
        Debug.Assert(action != null);

        this._dispatcher.BeginInvoke(action);
    }
}