Resources in modularized WPF (with Caliburn.Micro and MEF)

Question

I have searched for an answer for this question all day without coming up with any solutions directly applicable to my case, or anything that works (in the one case I found that was applicable).

I have a Caliburn.Micro framework set up to use MEF, and I load my modularized elements just fine. The one thing missing is getting WPF to recognize the resources I use in one of my modules.

How modules are loaded in my app bootstrapper

[ImportMany]
private IEnumerable<IMyModule> _myModules;

protected override void Configure()
{
    // Because Configure() is also called from SelectAssemblies(), we cannot instantiate MEF again because it will create conflicts.
    if (_configured)
    {
        return;
    }

    AggregateCatalog aggregateCatalog = new AggregateCatalog(AssemblySource.Instance.Select(x => new AssemblyCatalog(x)).OfType<ComposablePartCatalog>());
    aggregateCatalog.Catalogs.Add(new DirectoryCatalog(ConfigurationManager.AppSettings["MyModuleFolderLocation"]));
    aggregateCatalog.Catalogs.Add(new AssemblyCatalog(GetType().Assembly));

    _container = new CompositionContainer(aggregateCatalog);

    CompositionBatch batch = new CompositionBatch();
    batch.AddExportedValue<IWindowManager>(new WindowManager());
    batch.AddExportedValue<IEventAggregator>(new EventAggregator());
    batch.AddExportedValue(_container);

    _container.Compose(batch);
    _container.SatisfyImportsOnce(this);

    _configured = true;
}

protected override IEnumerable<Assembly> SelectAssemblies()
{
    // SelectAssemblies() is called before Configure(), so manually force Configure() to run first so that MEF is instantiated properly
    Configure();

    if (!_configured)
    {
        throw new Exception("Unable to configure assemblies");
    }

    List<Assembly> assemblies = new List<Assembly>();

    assemblies.Add(Assembly.GetExecutingAssembly());

    // Need to add all module assemblies so that Caliburn will be able to find the View for a ViewModel
    foreach(IMyModule myModule in _myModules)
    {
        Assembly assembly = myModule.GetType().Assembly;
        assemblies.Add(assembly);
    }

    return assemblies.Distinct();
}

This works just fine to get a module to be displayed properly.

But when a module has used an image, this image is never displayed, because this kind of loading apparently doesn't take resources into account. I create a Resources.resx file in the module project and add an image to that. The image file that is presented in Visual Studio then has a Build Action that says "Resource" and "Do not copy (to output directory)". This should mean that the image is embedded in the resulting DLL file.

The image is placed in a folder called "Resources" in the module project, and the XAML use it like this:

<Image Source="/Resources/myImage.png" />

The image is displayed in the preview in Visual Studio, but is not displayed when the application runs.

What I have tried that didn't work

• Referencing the image in another way: <Image Source="pack://application:,,,/Resources/myImage.png" />
• Getting the resources in BAML form and reinserting them into the executing assembly, like in this question: Instantiate ResourceDictionary xaml from other Assembly (which causes an OutOfMemoryException on this line var reader = new Baml2006Reader(stream);)
• A lot of other answers that reference ResourceDictionary, but I have a Resource.resx file (which only generates an internal class that is not a ResourceDictionary)

The question remains

How can I get WPF/Caliburn.Micro to recognize resources from a DLL loaded by MEF?

Answer 1

Answer

Use this syntax for the Source property for images with Build Action: Resource

<Image Source="/AssemblyName;component/Resources/MyImage.png" />

Where AssemblyName is the name of the assembly (as defined in the project properties), and /Resource/MyImage.png is the path to the image (as defined in the project). component must always be present.

Side note

After a lot of help from @StepUp I initially decided to ask a new question using what was learned from this question and rephrasing everything to be more specific to my problem.

When writing this new question I ended up googling for phrases and commands that might help with the rephrasing, and I stumbled upon this page: http://www.geekchamp.com/tips/wp7-working-with-images-content-vs-resource-build-action

Apparently, the WPF Image control has a ton of ways to define the Source property. I had already tried quite a lot of various Source inputs and thought I had tried them all, but the page linked to above proved me wrong.

As far as I have been able to test, the syntax described above seems to work for images marked with Build Action: Resource. Therefore I no longer need to have a RESX file for the images, and I do not need any special handling when bootstrapping MEF.

Answer 2

At first, you should read the assembly with Style. Then, it is neccessary to read BAML files from external library using Baml2006Reader. Let me show an example:

private GetResourceDictionary()
{
    string address = @"WpfCustomControlLibrary1.dll";
    Assembly skinAssembly = Assembly.LoadFrom(address);
    string[] resourceDictionaries = skinAssembly.GetManifestResourceNames();
    Stream bamlStream = null;            
    string name = "themes/AllStylesDictionary.baml";//themes/AllStylesDictionary.baml
    foreach (string resourceName in resourceDictionaries)
    {
       ManifestResourceInfo info = skinAssembly.GetManifestResourceInfo(resourceName);
       if (info.ResourceLocation != ResourceLocation.ContainedInAnotherAssembly)
       {
          Stream resourceStream = skinAssembly.GetManifestResourceStream(resourceName);
          using (ResourceReader reader = new ResourceReader(resourceStream))
          {
              foreach (DictionaryEntry entry in reader)
              {
                 if (entry.Key.ToString().Equals(name.ToLower()))
                 {
                     bamlStream = entry.Value as Stream;
                 }
              }
          }
        }
    }   
    ResourceDictionary rd = LoadBaml<ResourceDictionary>(bamlStream);
    Application.Current.Resources.MergedDictionaries.Add(rd);
    Style style = Application.Current.Resources.MergedDictionaries[0]["myStyle"] as Style;
    button.Style = style;
}

and:

public static T LoadBaml<T>(Stream stream)
{
   var reader = new Baml2006Reader(stream);
   var writer = new XamlObjectWriter(reader.SchemaContext);
   while (reader.Read())
      writer.WriteNode(reader);
   return (T)writer.Result;
}

Update:

If you want to load an image from another libary, you should use the following code:

yourImage.Source = new Bitmap(System.Reflection.Assembly.GetEntryAssembly().
    GetManifestResourceStream("MyProject.Resources.myimage.png"));

Update1:

To load an image from the external dll.

foreach (DictionaryEntry entry in reader)
{
   if (entry.Key.ToString().Equals(name.ToLower()))
   {
        bamlStream = entry.Value as Stream;
        BitmapImage bmp = LoadImage(bamlStream);
        img.Source = bmp;
   }
}

public static BitmapImage LoadImage(Stream stream) 
{ 
   BitmapImage bmi; 
   using (MemoryStream ms1 = new MemoryStream()) 
   { 
      stream.CopyTo(ms1); 
      bmi = new BitmapImage(); 
      bmi.BeginInit(); 
      bmi.StreamSource = new MemoryStream(ms1.ToArray()); 
      bmi.EndInit(); 

   } 
   return bmi; 
}