如何编程开启和关闭windows的桌面扩展功能？

Question

    windows的桌面扩展功能，可以使用第2个显示器，在delphi中，如何编程开启和关闭windows的桌面扩展功能？我有个VBS脚本，可以通过模拟点击的方法实现，那么，在delphi中，如何实现呢？可以通过修改注册表实现吗？
  VBS脚本如下：
Option Explicit 
Dim WshShell, Dummy, SplashOn Error Resume Next Set WshShell = WScript.CreateObject("WScript.Shell") 'Main
Call DoIt
WScript.QuitSub DoIt
wshshell.Run("%systemroot%\system32\control.exe desk.cpl,@0,3")' Give Display Properties time to load
WScript.Sleep 1000 
WshShell.SendKeys "2"
WScript.Sleep 10 
WshShell.SendKeys "%E"
WScript.Sleep 500 
WshShell.SendKeys "%A"
WshShell.SendKeys "{TAB}"
WshShell.SendKeys "{TAB}"
WshShell.SendKeys "{TAB}"
WshShell.SendKeys "{TAB}"
WshShell.SendKeys "{TAB}"
WshShell.SendKeys "{TAB}"
WshShell.SendKeys "{TAB}"
WshShell.SendKeys "{TAB}"
WshShell.SendKeys "{TAB}"
WshShell.SendKeys "{TAB}"WshShell.SendKeys "{ENTER}"
End Sub 'DoIt

Answer 1

用DELPHI也可以实现的
unit DisplayStruct;interface
uses
  Windows;
type
   TEZDevMode = packed record
    dmDeviceName: array[0..CCHDEVICENAME - 1] of AnsiChar;
    dmSpecVersion: Word;
    dmDriverVersion: Word;
    dmSize: Word;
    dmDriverExtra: Word;
    dmFields: DWORD;
    dmPosition:TPoint;
    dmDisplayOrientation:DWORD;
    dmDisplayFixedOutput:DWORD;
    dmColor: SHORT;
    dmDuplex: SHORT;
    dmYResolution: SHORT;
    dmTTOption: SHORT;
    dmCollate: SHORT;
    dmFormName: array[0..CCHFORMNAME - 1] of AnsiChar;
    dmLogPixels: Word;
    dmBitsPerPel: DWORD;
    dmPelsWidth: DWORD;
    dmPelsHeight: DWORD;
    dmDisplayFlags: DWORD;
    dmDisplayFrequency: DWORD;
    dmICMMethod: DWORD;
    dmICMIntent: DWORD;
    dmMediaType: DWORD;
    dmDitherType: DWORD;
    dmICCManufacturer: DWORD;
    dmICCModel: DWORD;
    dmPanningWidth: DWORD;
    dmPanningHeight: DWORD;
  end;
   procedure TFormEzConfig.cmb_ScreenNumChange(Sender: TObject);
var
  DisplayDevice: TDisplayDevice;
  Dm: TEZDevMode;
  DevM: PDevMode;
  hr: integer;
begin
  inherited;
  DisplayDevice.cb := SizeOf(TDisplayDevice);
  if EnumDisplayDevices(nil, cmb_ScreenNum.ItemIndex, DisplayDevice, 0) then    if (DisplayDevice.StateFlags and DISPLAY_DEVICE_PRIMARY_DEVICE) = 0 then
    begin
      if ((DisplayDevice.StateFlags and DISPLAY_DEVICE_ATTACHED_TO_DESKTOP) = 0) then
      begin
        FillChar(Dm, sizeof(TEZDevMode), #0);
        dm.dmSize := SizeOf(TEZDevMode);
        dm.dmPosition.X := Screen.Monitors[0].Width;
        dm.dmFields := DM_POSITION;
        hr := ChangeDisplaySettingsEx(DisplayDevice.DeviceName, DevMode(Dm), 0, CDS_NORESET or CDS_UPDATEREGISTRY, nil);
        DevM := nil;
        hr := ChangeDisplaySettings(DevM^, CDS_RESET);
        if hr <> DISP_CHANGE_SUCCESSFUL then
        begin
          MessageBox(handle, '对不起无法启用您选择的显视设备，请确保相应的显视设备与显示器的' + #13#10 + '正常连接后再启用',
            '友情提示', MB_OK or MB_ICONWARNING);
          TComboBox(Sender).ItemIndex := 0;
        end;
      end; // A second call to ChangeDisplay
    end;
end;implementationend.

Answer 2

simb 的方法不错,我试验了.

Answer 3

PASCAL代码的，在DELPHI2009中不能通过，显示DevMode(Dm),位置的类型不匹配，怎么办？

Answer 4

to 3楼：
这是由于Delphi2009对Unicode的支持而产生的变动。
只要把AnsiChar改成WideChar就行了
像这样：
type
   TEZDevMode = packed record
    dmDeviceName: array[0..CCHDEVICENAME - 1] of WideChar;
    dmSpecVersion: Word;
    dmDriverVersion: Word;
    dmSize: Word;
    dmDriverExtra: Word;
    dmFields: DWORD;
    dmPosition:TPoint;
    dmDisplayOrientation:DWORD;
    dmDisplayFixedOutput:DWORD;
    dmColor: SHORT;
    dmDuplex: SHORT;
    dmYResolution: SHORT;
    dmTTOption: SHORT;
    dmCollate: SHORT;
    dmFormName: array[0..CCHFORMNAME - 1] of WideChar;
    dmLogPixels: Word;
    dmBitsPerPel: DWORD;
    dmPelsWidth: DWORD;
    dmPelsHeight: DWORD;
    dmDisplayFlags: DWORD;
    dmDisplayFrequency: DWORD;
    dmICMMethod: DWORD;
    dmICMIntent: DWORD;
    dmMediaType: DWORD;
    dmDitherType: DWORD;
    dmICCManufacturer: DWORD;
    dmICCModel: DWORD;
    dmPanningWidth: DWORD;
    dmPanningHeight: DWORD;
  end;