WPF custom derived control style

Question

I have a custom control derived from Button:

    class MyControl : Button{}

And suppose, this class is empty (has no members).

In the application's main window resources I use ResourceDictionary that contains styles for most WPF controls (so called theme):

    <ResourceDictionary Source="BureauBlue.xaml" />

So, all controls on the window look like it is defined in that theme file. But the styles are not affected on MyControl controls. How can I do MyControl to look same as a Button controls?

Update: The style for Button in BureauBlue.xaml has no key and is defined in the following way:

    <Style TargetType="{x:Type Button}" BasedOn="{x:Null}"> ...</Style>

Answer 1

Check if style for Button is there in your BureauBlue.xaml and remove x:key attribute from the style if it is there

Answer 2

The TargetType property doesn't work for classes that derive from the specified type. See this question

Answer 3

You override the DefaultStyleKey's metadata in your static constructor:

static MyControl()
{
    DefaultStyleKeyProperty.OverrideMetadata(
        typeof(MyControl),
        new FrameworkPropertyMetadata(typeof(MyControl)));
}

Then, in your resources, you can base its style on the button:

<Style TargetType="{x:Type lcl:MyControl}" BasedOn="{StaticResource {x:Type Button}}" />

I've tried in the past to override the DefaultStyleKey's metadata to point to the base class (Button in your case), but it doesn't seem to work.