Retrieves the return value of the asynchronous operation represented by the IAsyncResult passed.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
If the asynchronous operation has not been completed, this function will block until the result is available.
In addition to the InvokeRequired property, there are four methods on a control that are thread safe: Invoke, BeginInvoke, , and CreateGraphics if the handle for the control has already been created. Calling CreateGraphics before the control's handle has been created on a background thread can cause illegal cross thread calls. For all other method calls, you should use one of the invoke methods to marshal the call to the control's thread.