急救，如何实现行打印

Question

可以，下面的这个方法不错。AssignPRN(f); 
                     Rewrite(f); 
                     Printer.Canvas.Font.Name := '宋体'; 
                     Printer.Canvas.Font.Size := 10; 
                     Printer.Canvas.Font.PixelsPerInch := GetDeviceCaps(Printer.Canvas.Handle, LOGPIXELSY); 
                     //  SetTextAlign(Printer.Canvas.Handle, TA_CENTER); 
                     Writeln(f, '             欢迎光临'); 
                     Writeln(f, '===================================='); 
                     Writeln(f, '货码/货名      数量    单价    金额 '); 
                     Writeln(f, ''); 
                   Writeln(f, ''); 
                   Writeln(f, ''); 
                   System.CloseFile(f); 下面可以饶过打印驱动
procedure PrintFile(const sFileName: string);
const
  BufSize = 16384;
type
  TDoc_Info_1 = record
    pDocName: pChar;
    pOutputFile: pChar;
    pDataType: pChar;
  end;
var
  Count, BytesWritten: integer;
  hPrinter: THandle;
  Device : array[0..255] of char;
  Driver : array[0..255] of char;
  Port   : array[0..255] of char;
  hDeviceMode: THandle;
  DocInfo: TDoc_Info_1;
  f: file;
  Buffer: Pointer;
begin
  Printer.PrinterIndex := -1;
  Printer.GetPrinter(Device, Driver, Port, hDeviceMode);
  if not WinSpool.OpenPrinter(@Device, hPrinter, nil) then exit;
  DocInfo.pDocName := 'MyDocument';
  DocInfo.pOutputFile := nil;
  DocInfo.pDatatype := 'RAW';
  if StartDocPrinter(hPrinter, 1, @DocInfo) = 0 then
  begin
    WinSpool.ClosePrinter(hPrinter);
    exit;
  end;
  if not StartPagePrinter(hPrinter) then
  begin
    EndDocPrinter(hPrinter);
    WinSpool.ClosePrinter(hPrinter);
    exit;
  end;
  System.Assign(f, sFileName);
  try
    Reset(f, 1);
    GetMem(Buffer, BufSize);
    while not eof(f) do
    begin
      Blockread(f, Buffer^, BufSize, Count);
      if Count > 0 then
      begin
        if not WritePrinter(hPrinter, Buffer, Count, BytesWritten) then
        begin
          EndPagePrinter(hPrinter);
          EndDocPrinter(hPrinter);
          WinSpool.ClosePrinter(hPrinter);
          FreeMem(Buffer, BufSize);
          exit;
        end;
      end;
    end;
    FreeMem(Buffer, BufSize);
    EndDocPrinter(hPrinter);
    WinSpool.ClosePrinter(hPrinter);
  finally
    System.Closefile( f );
  end;
end;上面的例子改一改就可以做成通用的行打
注意 uses 子句里一定要加上 WinSpool