用程序设置打印纸类型的问题

Question

我想用程序设置打印机的纸张类型，代码如下：
procedure TForm1.Button1Click(Sender: TObject);
var
  ADevice, ADriver, APort: array[0..255] of Char;
  DeviceHandle: THandle;
  DevMode: PDeviceMode;
begin
    //初始化打印机
    Printer.GetPrinter(ADevice, ADriver, APort, DeviceHandle);
    if DeviceHandle = 0 then
    begin
      Printer.PrinterIndex := Printer.PrinterIndex;
      Printer.GetPrinter(ADevice, ADriver, APort, DeviceHandle);
    end;
    if DeviceHandle = 0 then
      Raise Exception.Create('不能初始化打印机！')
    else
      DevMode := GlobalLock(DeviceHandle);
    if DeviceHandle <> 0 then
    begin
      with DevMode^ do
      begin
        dmFields := dmFields or DM_ORIENTATION;
        //在下面这里设置打印方向
        dmOrientation := DMORIENT_LANDSCAPE; //DMORIENT_PORTRAIT
        Printer.SetPrinter(ADevice, ADriver, APort, DeviceHandle);
        GlobalUnLock(DeviceHandle);
      end;
    end;    PrinterSetupDialog1.Execute; //验证一下设置是否成功了
end;我将打印方向设为了横向，但PrinterSetupDialog对话中显示的仍然是纵向，不知为什么，请问怎么才能使PrinterSetupDialog中的设置随程序设置的改变而改变呢？

Answer 1

Var
  PrnDevice, PrnDriver, PrnPort: Array[0..255] Of Char;
  PrnHandle: THandle;
  PrnMode: PDeviceMode;
Begin
  Printer.GetPrinter(PrnDevice, PrnDriver, PrnPort, PrnHandle);
  If PrnHandle = 0 Then
    Raise Exception.Create('无法获取系统打印机信息！')
  Else
    Begin
      PrnMode:= GlobalLock(PrnHandle);
      With PrnMode^ Do
        Begin
          //打印份数
          dmFields:= dmFields Or dmCopies;
          dmCopies:= 1;          //打印方向
          dmFields:= dmFields Or dmOrientation;
          //dmOrientation:= DMORIENT_LANDSCAPE;
          dmOrientation:= DMORIENT_PORTRAIT;          //纸张大小
          dmFields:= dmFields Or dmPaperSize;
          //dmPaperSize:= 162;
          dmPaperSize:= DMPAPER_USER;          dmFields:= dmFields Or dmPaperWidth;
          //dmPaperWidth:= 2100;
          dmPaperWidth:= 1580;          dmFields:= dmFields Or dmPaperLength;
          //dmPaperLength:= 2970;
          dmPaperLength:= 1018;          dmFields:= dmFields Or PrnMode^.dmLogPixels;
          dmLogPixels:= 300;
          ResetDC(Printer.Handle, PrnMode^);
        End;我的代码，你试试看。
我这边运行没问题。

Answer 2

ResetDC(Printer.Handle, PrnMode^);
你加上了么？