Model-View-ViewModel(MVVM) with MEF

今天看David Wynne 写的一篇如果在MVVM中使用MEF进行扩展的文章，总的来说例子写的很好，可是有一个很命的地方，View是硬编码(hardcoded)到Main window中的，我就借花献佛，把它的例子稍稍改一下，以使它真正的好扩展。

 

基本上改动不大，直接贴代码吧

App.cs 

 public partial class App : Application
    {
private static CompositionContainer _container;

internal static CompositionContainer Container
        {
get
            {
return _container;
            }
        }

        [Import("MainWindow")]
public new Window MainWindow
        {
get { return base.MainWindow; }
set { base.MainWindow = value; }
        }

protected override void OnStartup(StartupEventArgs e)
        {
base.OnStartup(e);
            var catalog = new AggregateCatalog();
            catalog.Catalogs.Add(new AssemblyCatalog(Assembly.GetExecutingAssembly()));
//catalog.Catalogs.Add(new DirectoryCatalog("Extensions"));
            _container = new CompositionContainer(catalog);

            var batch = new CompositionBatch();
            batch.AddPart(this);

try
            {
                _container.Compose(batch);
                MainWindow.Show();
            }
catch
            {
                Shutdown();
            }

        }
    }

 

下面是对应的MainWindow.Xaml

 

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"       
        Loaded="Window_Loaded"
        Title="MainWindow">
<StackPanel x:Name="WidgetsPanel"></StackPanel>
</Window>