Control.InvokeRequired Property
Gets a value indicating whether the caller must call an invoke method when making method calls to the control because the caller is on a different thread than the one the control was created on
获取一个值,该值指示调用方在对控件进行方法调用时是否必须调用调用方法,因为调用方所在的线程与创建控件的线程不同