如何避免在两个类似的WinForms上复制逻辑？

I have two forms, form A and form B. These forms must differ in appearance, but they share a lot of logic. The problem is that this logic is tied to the appearance (validation on button click, events being fired, etc.). For example, I have a name field, and when the save button is pressed, I need to fire an event which causes the parent form to validate the record name to avoid duplicates. Both forms need this logic, but their save buttons are in different places, and the tooltip that is shown when an error occurs also needs to appear in a different place. This is just one example, but does anyone know of a way that I can avoid copying and pasting code here? Perhaps I am missing something obvious...I have two forms, form A and form B. These form