Custom controls SharePoint webpart Property Panel

Can you please give me an idea how to render custom controls in property panel of webpart? My Requirement is to add a dropdown list,TextBox and a button to add selected items in the textbox in property pane开发者_StackOverflow社区l. I am able to create TextBox,DropDown List and checkbox in property panel but found no way to create buttons and other controls.

Regards, Sharmila

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You would have to use a tool part for the same sample code is available at the following link Tool Part