由于工作需要，经朋友 （DS，FT）指点，先贴工作中代码，至于使用USB端口打印机，日后再说。

正在装载数据……

  TPrinterSett = record
    PrinterName: string;
    MinPaperSize: TPoint;
    MaxPaperSize: TPoint;
  end;

private
  FPrnSett: TPrinterSett;

uses
  Printers, WinSpool;

function GetMinMaxPaperSize: Boolean;
var
  R: DWORD;
  PrnName: string;
  hPrn: THandle;
  DevMode: TDeviceMode;

  pPrnInfo: PPrinterInfo2;
  dwNeeded: DWORD;
  PortName: string;
begin
  Result := False;
  if Printer.PrinterIndex < 0 then Exit;

  PrnName := Printer.Printers.Strings[Printer.PrinterIndex];
  if not OpenPrinter(PChar(PrnName), hPrn, nil) then Exit;

  try
    FPrnSett.PrinterName := PrnName;
    if not GetPrinter(hPrn, 2, nil, 0, @dwNeeded) then
    begin
      pPrnInfo := AllocMem(dwNeeded);
      try
        if GetPrinter(hPrn, 2, pPrnInfo, dwNeeded, @dwNeeded) then
        begin
          PortName := pPrnInfo.pPortName;
          if Pos('LPT', PortName) = 0 then Exit;
        end else begin
          Exit;
        end;
      finally
        FreeMem(pPrnInfo);
      end;
    end;

    R := DeviceCapabilities(
      PChar(PrnName), PChar(PortName), DC_MINEXTENT, nil, @DevMode);

    if R > 0 then
    begin
      with FPrnSett do
      begin
        MinPaperSize.x := LoWord(R);
        MinPaperSize.y := HiWord(R);
      end;
      {
      ShowMessage('Min Paper Width: ' + IntToStr(FPrnSett.MinPaperSize.x) + #13+
                  'Min Paper Length: ' + IntToStr(FPrnSett.MinPaperSize.y));
      }
    end else begin
      Exit;
    end;

    R := DeviceCapabilities(
      PChar(PrnName), PChar(PortName), DC_MAXEXTENT, nil, @DevMode);

    if R > 0 then
    begin
      with FPrnSett do
      begin
        MaxPaperSize.x := LoWord(R);
        MaxPaperSize.y := HiWord(R);
      end;
      {
      ShowMessage('Max Paper Width: ' + IntToStr(FPrnSett.MaxPaperSize.x) + #13+
                  'Max Paper Length: ' + IntToStr(FPrnSett.MaxPaperSize.y));
      }
    end else begin
      Exit;
    end;

    Result := True;
  finally
    ClosePrinter(hPrn);
  end;
end;

 

本文来源：http://blog.csdn.net/swayi21/archive/2007/08/15/1745362.aspx