New Post: PropertyGrid: Custom Items Source and ReadOnly Attribute

In v2.5. when using EditorAttribute on a readOnly property (only set or with ReadOnlyAttribute set to true), it won't default to a TextBlock...unless the editor.IsEnabled is set to False in ITypeEditor.ResolveEditor(). In that case, the editor won't be enabled.

For ItemsSource attribute and readOnlyAttribute set to true, the ReadOnly won't be applied. If you want it to be ReadOnly, use a EditorAttribute to create a ComboBox and set its IsEnable property to False.