delphi 如何发二进制字符到打印机|笨鱼技术网

Problem/Question/Abstract:

How to send a raw string to the printer

Answer:

procedure PrintRawStr(const S: ANSIString);

Uses WinSpool, Printers;

var
sDefaultPrinter: string;
Handle: THandle;
dwN: DWORD;
diDocInfo1: TDocInfo1; // Uses WinSpool
bP: BYTE;

begin
// Get the default printer or the printer choosen in the Printer Setup Dialog
// if you have one in the application
if Printer.Printers.Count > 0 then
begin
    sDefaultPrinter := Printer.Printers[Printer.PrinterIndex]; // Uses Printers
    //uses Printers, get default printer
    bP := Pos(' on ', sDefaultPrinter);
    if bP > 0 then
      sDefaultPrinter := Copy(sDefaultPrinter, 1, bP - 1);
end
else
    Exit; // No printers installed on this system...

if not OpenPrinter(PChar(sDefaultPrinter), Handle, nil) then
begin
    case GetLastError of
      87: ShowMessage('Printer name does not exists.');
    else
      ShowMessage('Error ' + IntToStr(GetLastError)); // Uses Dialogs
    end;
    Exit; // Cannot find the printer
end;

with diDocInfo1 do
begin
    pDocName := PChar('Print job raw'); // Will be seen in printer spooler
    pOutputFile := nil;
    pDataType := 'RAW';
end;

StartDocPrinter(Handle, 1, @diDocInfo1);
StartPagePrinter(Handle);
WritePrinter(Handle, PChar(S), Length(S), dwN);
EndPagePrinter(Handle);
EndDocPrinter(Handle);
ClosePrinter(Handle);
end;