除了使用 Pascal 文件访问功能进行打印之外，另一种方法是使用 Windows API 进行后台处理程序。

function PrintWithSpooler(const Name: string; const Data: AnsiString): integer;
var
  hPrinter: THandle;
  DocInfo: TDocInfo1;
  bSuccess: boolean;
  dwBytesWritten: DWORD;
begin
  result := S_OK;
  bSuccess := false;

  DocInfo.pOutputFile := nil;
  DocInfo.pDatatype := 'RAW';
  DocInfo.pDocName := 'Label';

  if OpenPrinter(PChar(Trim(Name)), hPrinter, nil) then
  begin
    try
      if StartDocPrinter(hPrinter, 1, @DocInfo) > 0 then
      begin
        try
          if StartPagePrinter(hPrinter) then
          begin
            try
              bSuccess := WritePrinter(hPrinter, Pointer(Data), Length(Data), dwBytesWritten);
            finally
              EndPagePrinter(hPrinter);
            end;
          end;
        finally
          EndDocPrinter(hPrinter);
        end;
      end;
    finally
      ClosePrinter(hPrinter);
    end;
  end;

  if not bSuccess then
  begin
    result := GetLastError;

    // in case there was no error from GetLastError
    if result = S_OK then
      result := S_FALSE;
  end;
end;