I am creating a Windows application for a restaurant. I want to provide functionality for floor management, so I've created some classes such as table, chair, etc. The restaurant owner arranges the tables and chairs according to [ourself]. How can Drag'n'Drop [object like button in a panel and after drag it position arrange.. abd save.]
(Rephrased a little. The sentence parts in square brackets are unchanged.)
I am going to assume you are developing your application with Windows Forms (a.k.a. Winforms), and not Windows Presentation Foundation (a.k.a. WPF).
If that is correct, have a look at the MSDN article Performing Drag-and-Drop Operations in Windows Forms for general information about how to implement drag-and-drop with Winforms.
If you need more specific information, you will probably have to ask a more specific question.