How to bind to a collection contained in an other project/namespace?

Question

i did this:

this.combobox.ItemsSource = Common.Component.ModuleManager.Instance.Modules;

to bind the combobox to a collection, which is located in an other project/namespace. But i had to move the ComboBox into a DataTemplate.

Now i need to do something like that:

<ComboBox ItemsSource="{Binding Common.Component.ModuleManager.Instance.Modules}"/>

I don't want to list all of my tries, but none were successful.
Any better Ideas?

Answer 1

You need to map the .NET namespace to an XML namespace at the top of your XAML file:

<Window 
    x:Class="WindowsApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:q="clr-namespace:Common.Component">

So now "q" is mapped to the "Common.Component" namespace. Now you can use the x:Static markup extension to access the static "Instance" property of your ModuleManager class:

<ComboBox
    ItemsSource="{Binding Modules,Source={x:Static q:ModuleManager.Instance}}" />

See if that works for you.

Edit

One more thing: If your "Common.Component" namespace lives in a separate assembly, you need to tell the XAML that:

xmlns:q="clr-namespace:Common.Component;assembly=CommonAssemblyFilename"

Answer 2

On an unrelated note you might want to bind to an Observable collection instead for performance. More WPF optimization details here.

Binding IEnumerable to an ItemsControl forces WPF to create a wrapper IList<(Of <(T>)>) object, which means your performance is impacted by the unnecessary overhead of a second object.

Answer 3

Ok, i found a workaround. There must be a Problem if the collection is contained in an other assembly.

I added a new class to the assembly of the XAML and the Binding.

public static class ResourceHelper
{
    public static IEnumerable<Common.Component.Module> Modules = Common.Component.ModuleManager.Instance.Modules;
}

Then i changed the binding to

<ComboBox ItemsSource="{Binding Path=.,Source={x:Static e:ResourceHelper.Modules}}"/>

And this works fine.
Thx Matt for your help.