RM报表 刷新打印机列表

procedure TRMReport.ShowPreparedReport;
var
  s: string;
  lPreviewForm: TRMPreviewForm;
begin
  RMCurReport := Self;
  Flag_PrintBackGroundPicture := True;
  if (not FThreadPrepareReport) and (EndPages.Count = 0) then Exit;

  FCurrentBand := nil;
  FCurrentPage := nil;
  FMasterReport := Self;
  FDocMode := rmdmPreviewing;
  s := RMLoadStr(SPreview);
  if ReportInfo.Title <> '' then
    s := s + ' - ' + ReportInfo.Title
  else if FileName <> '' then
    s := s + ' - ' + ExtractFileName(FileName)
  else
    s := s + ' - ' + RMLoadStr(SUntitled);

  if Assigned(Preview) then
  begin
    FCurPreview := Preview;
    Preview.ShowReport(Self);
  end
  else
  begin
    if csDesigning in ComponentState then
      lPreviewForm := TRMPreviewForm.Create(nil)
    else
      lPreviewForm := TRMPreviewForm.Create(Self);//这里

  { TRMPreviewForm }
  TRMPreviewForm = class(TForm)
    ImageList1: TImageList;
    procedure FormCreate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure FormShow(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure FormKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
  private
    { Private declarations }
    FDoc: Pointer;
    FViewer: TRMPreview;//这里 包括 预览对象
    FPopupMenu: TRMPopupMenu;
    FPopupMenuPrint: TRMPopupMenu;

  { TRMPreview }
  TRMPreview = class(TRMVirtualPreview)
  private
    FShowToolbar: Boolean;
    FOnBtnExitClickEvent: TNotifyEvent;
    FOnSaveReportEvent: TRMPreviewSaveReportEvent;

    Dock971: TRMDock;
    ToolbarStand: TRMToolbar;
    BtnExit: TRMToolbarButton;
    btn100: TRMToolbarButton;
    btnOnePage: TRMToolbarButton;
    btnPageSetup: TRMToolbarButton;
    btnPageWidth: TRMToolbarButton;
    btnShowOutline: TRMToolbarButton;
    ToolbarSep972: TRMToolbarSep;
//{$IFDEF USE_TB2K}
//    btnPrint: TRMSubmenuItem;
//{$ELSE}
    btnPrint: TRMToolbarButton; //打印按钮
//{$ENDIF}

procedure TRMPreview.btnPrintClick(Sender: TObject);
begin
  if (Report = nil) or (not btnPrint.Visible) then Exit;

  Print;//打印方法
end;

procedure TRMVirtualPreview.Print;
var
  lSavePrinterIndex: Integer;
  lNeedSave: Boolean;
  lPages: string;
  lForm: TRMPrintDialogForm;
begin
  if FPrepareReportFlag then Exit;
  if (GetEndPages = nil) or (RMPrinters.Count = 2) then Exit;

  lForm := TRMPrintDialogForm.Create(nil);//打印对话框

procedure TRMPrintDialogForm.FormShow(Sender: TObject);
begin
  cmbPrinters.Items.Assign(RMPrinters.Printers);//读取打印机列表
  cmbPrinters.Items.Delete(1);//删除虚拟打印机
  FOldIndex := CurrentPrinter.PrinterIndex;
  if FOldIndex <= 1 then
    cmbPrinters.ItemIndex := 0
  else
    cmbPrinters.ItemIndex := FOldIndex - 1;
  if cmbPrinters.ItemIndex < 0 then
    cmbPrinters.ItemIndex := 0;
  chkCollateClick(nil);

  cmbPrintAll.ItemIndex := 0;
  cmbPrintAll.Left := Label5.Left + Label5.Width + 11;

  cmbScalePapers.ItemIndex := -1;

  cmbPrintersChange(nil);
  FSpinOffsetTop.Value := FPrintOffsetTop / 10000;
  FSpinOffsetLeft.Value := FPrintOffsetLeft / 10000;
end;

constructor TRMPrinterList.Create;
begin
  inherited Create;

  FLock := TCriticalSection.Create;

  FPrinters := TStringList.Create;
  BuildPrinterList;//读取打印机列表
  GetDefaultPrinter;
end;

procedure TRMPrinterList.BuildPrinterList;
var
  lLineCur, lPort: PChar;
  lBuffer, lPrinterInfo: PChar;
  lFlags, lCount, lNumInfo: DWORD;
  I: Integer;
  lLevel: Byte;
  tmp: TRMPrinterInfo;
  lStr: string;
begin
  FLock.Acquire;
  try
    FreePrinterList; FPrinters.Clear;
    if Win32Platform = VER_PLATFORM_WIN32_NT then
    begin
      lFlags := PRINTER_ENUM_CONNECTIONS or PRINTER_ENUM_LOCAL;
      lLevel := 4;
    end
    else
    begin
      lFlags := PRINTER_ENUM_LOCAL;
      lLevel := 5;
    end;
    
    lCount := 0;
    EnumPrinters(lFlags, nil, lLevel, nil, 0, lCount, lNumInfo);
    if lCount > 0 then
    begin
      GetMem(lBuffer, lCount);
      try
        if not EnumPrinters(lFlags, nil, lLevel, PByte(lBuffer), lCount, lCount, lNumInfo) then
          Exit;

        lPrinterInfo := lBuffer;
        for I := 0 to lNumInfo - 1 do
        begin
          if lLevel = 4 then
          begin
            with PPrinterInfo4(lPrinterInfo)^ do
            begin
              tmp := TRMPrinterInfo.Create(nil, pPrinterName, nil);
              FPrinters.AddObject(pPrinterName, tmp);
              Inc(lPrinterInfo, sizeof(TPrinterInfo4));
            end;
          end
          else
          begin
            with PPrinterInfo5(lPrinterInfo)^ do
            begin
              lLineCur := pPortName;
              lPort := FetchStr(lLineCur);
              while lPort^ <> #0 do
              begin
                lStr := Format(SDeviceOnPort, [pPrinterName, lPort]);
                tmp := TRMPrinterInfo.Create(nil, pPrinterName, lPort);
                FPrinters.AddObject(lStr, tmp);
                lPort := FetchStr(lLineCur);
              end;
              
              Inc(lPrinterInfo, sizeof(TPrinterInfo5));
            end;
          end;
        end;
      finally
        FreeMem(lBuffer, lCount);
      end;
    end;

    tmp := TRMPrinterInfo.Create(nil, PChar(RMLoadStr(SDefaultPrinter)), nil);
    FPrinters.InsertObject(0, RMLoadStr(SDefaultPrinter), tmp); //默认打印机
    
    tmp := TRMPrinterInfo.Create(nil, PChar(RMLoadStr(SVirtualPrinter)), nil); // 虚拟打印机
    FPrinters.InsertObject(1, RMLoadStr(SVirtualPrinter), tmp);
  finally
    Flock.Release;
  end;
end;

procedure TRMPrinterList.Refresh;
begin
  FLock.Acquire;
  try
    BuildPrinterList;
  finally
    Flock.Release;
  end;
end;