调整手柄

• Event is raised when the user finishes resizing a form , typically by dragging one of the borders or the sizing grip located on the lower - right corner of the form , and then releasing it
  用户完成调整窗体大小操作（通常通过单击或拖动其中一个边框或位于窗体右下角的大小调整手柄，然后将其释放）时会引发