No creation of a WPF window in a DLL project?
Make sure the project type is WPF User Control Library
when you create your project.
If it isn't then no sweat, just edit the csproj file and make sure the <ProjectTypeGuids>
element under Project/PropertyGroup
contain the following GUIDs
<ProjectTypeGuids>{60dc8134-eba5-43b8-bcc9-bb4bc16c2548};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
Also, make sure you reference PresentationFramework and System.Xaml in your project, or you will not get any WPF in your code.
I do it this way:1) create "WPF Application"2) remove App.xaml3) change Project properties -> Application Output type: to Class Library (originally there is Windows Application)
Otherwise you will get errors:
"Library project file cannot specify ApplicationDefinition element"
"The project file contains a property value that is not valid"