撤消日记功能：将控件重置为撤消

I'm writing an undo journal for my WPF data-entry screen, which will track changes across all the controls. When the user selects Undo, I want to not only revert the latest change, but put focus back in the control whose value is being reverted. I'm struggling with the best way to put that focus back.I'm writing an undo journal for my WPF data-ent