Thanks for response so fast.

I notice RibbonGroup is not a UIElement. How can we put RibbonGroup in to the usercontrol?

Hello,

Thank you for your feedback. I am glad that you resolved your issue and I believe that other community members may benefit from this as well.

Thanks again.

It works fine. Thanks

Hello,

I can suggest you define your TestRibbon class like this:

public class TestRibbon : XamRibbon
{
    public TestRibbon()
    {
        this.SetResourceReference(StyleProperty, typeof(XamRibbon));
    }
}

Please let me know if this helps you or you need further assistance on this matter.

Looking forward for your reply.

you can see the issue on the lefttop of picture

I attatch a sample to reproduce the issue