delphi中WebBrowser的parent改变时变成空白问题的解决（覆盖CreateWnd和DestroyWnd）

这段时间在做一个delphi界面打开网页的功能，且此网页所在窗口可完整显示，可缩小到另一个窗口的panel上显示

可是在改变网页所在窗口时，WebBrowser控件变成了空白

上网google了半天，终于在csdn上查到了解决方案：

原帖地址：http://bbs.csdn.NET/topics/200046109

uses
  SHDocVw, Windows, Controls, Forms, Classes;

type
  TMyWebBrowser = class(TWebBrowser)
  private
  protected
    ActualHandle: HWND;
    procedure CreateWnd; override;
    procedure DestroyWnd; override;
  public
  end;


{ TMyWebBrowser }
procedure TMyWebBrowser.CreateWnd;
begin
  if (ActualHandle <> 0) and IsWindow(ActualHandle) then
  begin
    WindowHandle := ActualHandle;
    ActualHandle := 0;
    Windows.SetParent(WindowHandle, TWinControl(Self).Parent.Handle);
    //Force a resize on the client window
    MoveWindow(WindowHandle, 0, 0, TWinControl(Self).Parent.Width,
      TWinControl(Self).Parent.Height, true);
  end
  else
    inherited;
end;

procedure TMyWebBrowser.DestroyWnd;
begin
  if (csDestroying in ComponentState) then
    inherited
  else
  begin
    //Parent to the Application window which is 0x0 in size
    Windows.SetParent(WindowHandle, Forms.Application.Handle);
    //save the WindowHandle
    ActualHandle := WindowHandle;
    //set it to 0 so Createwnd will be called again...
    WindowHandle := 0;
  end;
end;

http://blog.csdn.net/youthon/article/details/8450610