Why are strings truncated when using direct printing?
Question
I'm trying to print directly to a printer using esc/p commands (EPSON TM-T70) without using printer driver. Code found here.
However, if I try to print any strings, they are truncated. For example:
MyPrinter := TRawPrint.Create(nil);
try
MyPrinter.DeviceName := 'EPSON TM-T70 Receipt';
MyPrinter.JobName := 'MyJob';
if MyPrinter.OpenDevice then
begin
MyPrinter.WriteString('This is page 1');
MyPrinter.NewPage;
MyPrinter.WriteString('This is page 2');
MyPrinter.CloseDevice;
end;
finally
MyPrinter.Free;
end;
Would print only "This isThis is"! I wouldn't ordinarily use MyPrinter.NewPage
to send a line break command, but regardless, why does it truncates the string?
Also notice in RawPrint unit WriteString
function:
Result := False;
if IsOpenDevice then begin
Result := True;
if not WritePrinter(hPrinter, PChar(Text), Length(Text), WrittenChars) then begin
RaiseError(GetLastErrMsg);
Result := False;
end;
end;
If I put a breakpoint there and step through the code, then WrittenChars
is set to 14, which is correct. Why does it act like that?
No correct solution
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