How to implement the "Insert Document Field" dialog (WPF version)

This example demonstrates how to implement a custom "Insert Document Field" dialog to insert fields with corresponding formatting attributes into a WPF RichEditControl document.
The main idea of this approach was described in the following example:
How to implement the "Insert Document Field" dialog (WinForms version)

To build a solution demonstrated in this sample into an existing application, copy all modules and the "insertFieldIcon.png" image located in the InsertFieldModules folder and use a corresponding RegisterInsertFieldDialogCommand extension method to add the "Insert Field" command onto a current Ribbon control:

[C#]
MainRichEditControl.RegisterInsertFieldDialogCommand(grpCustomAction,newBitmapImage(newUri("pack://application:,,,/InsertFieldModules/insertFieldIcon.png")));

[VB.NET]
MainRichEditControl.RegisterInsertFieldDialogCommand(grpCustomAction, New BitmapImage(New Uri("pack://application:,,,/InsertFieldModules/insertFieldIcon.png")))