Starts the process of editing a WebPart control.
Assembly: System.Web (in System.Web.dll)
The method exists so that the process of editing controls can be done in distinct stages, giving developers more control over the process. The method performs a set of initial checks to ensure that webPart is in a state where it can be edited. If webPart passes all the checks, it is then set as the currently selected control (see the SelectedWebPart property), and the editing process can continue.