Delphi – 嵌入式应用程序滚动条不可见

基于 Embedding window into another process问题,我在我的主应用程序中嵌入了一个在主窗体上只有一个TWebBrowser组件的应用程序.即使我将它嵌入到TScrollBox组件中,当主应用程序调整大小时,滚动条也不会出现.我对这个问题做了一些研究,但没有成功.如何启用滚动条的滚动条？

LE：澄清问题：应用程序A是一个带有TWebBrowser组件的简单表单.应用程序B是主应用程序,它将应用程序A嵌入到放置在表单上的TScrollBox上,并将Align设置为alClient.将A嵌入B的代码

procedure ShowAppEmbedded(WindowHandle: THandle; Container: TWinControl);
var
  WindowStyle : Integer;
  FAppThreadID: Cardinal;
begin
  /// Set running app window styles.
  WindowStyle := GetWindowLong(WindowHandle,GWL_STYLE);
  WindowStyle := WindowStyle
                 - WS_CAPTION
                 - WS_BORDER
                 - WS_OVERLAPPED
                 - WS_THICKFRAME;
  SetWindowLong(WindowHandle,GWL_STYLE,WindowStyle);

  /// Attach container app input thread to the running app input thread,so that
  ///  the running app receives user input.
  FAppThreadID := GetWindowThreadProcessId(WindowHandle,nil);
  AttachThreadInput(GetCurrentThreadId,FAppThreadID,True);

  /// Changing parent of the running app to our provided container control
  Windows.SetParent(WindowHandle,Container.Handle);
  SendMessage(Container.Handle,WM_UPDATEUISTATE,UIS_INITIALIZE,0);
  UpdateWindow(WindowHandle);

  /// This prevents the parent control to redraw on the area of its child windows (the running app)
  SetWindowLong(Container.Handle,GetWindowLong(Container.Handle,GWL_STYLE) or WS_CLIPCHILDREN);
  /// Make the running app to fill all the client area of the container
  SetWindowPos(WindowHandle,Container.ClientWidth,Container.ClientHeight,SWP_NOZORDER);

  SetForegroundWindow(WindowHandle);
end;

调整主应用程序(B)的大小时,不会显示来自B的TScrollBox组件的滚动条,并且应用程序A停留在它上面是从请求设置的.

解决方案：根据Kobik的评论,应用程序A嵌入到与TScrollBox内的alClient对齐的TPanel内的应用程序B中.在OnPanelResize事件上运行以下代码：

if IsWindow(App_B_WindowHandle) then
    SetWindowPos(App_B_WindowHandle,Panel1.Width,Panel1.Height,SWP_ASYNCWINDOWPOS);