关于取得打印机名称，和端口的问题，本地打印没问题，但是网络打印机就出错(100分)

用的是这段程序：
procedure TprintSelForm.GetPrinterInfo;
var
pDevice: pChar;
pDriver: pChar;
pPort: pChar;
hDMode: THandle;
begin
GetMem(pDevice, cchDeviceName);
GetMem(pDriver, MAX_PATH);
GetMem(pPort, MAX_PATH);
try
Printer.GetPrinter(pDevice, pDriver, pPort, hDMode);
// label1.Caption := '打印机：' + StrPas(pDevice);
if lStrLen(pDriver) = 0 then
begin
GetProfileString('Devices', pDevice, '', pDriver, MAX_PATH);
pDriver[pos(',', pDriver) - 1] := #0;
end;
if lStrLen(pPort) = 0 then
label2.Caption := '端 口：' + GetPortName(StrPas(pDevice))
// GetProfileString('Devices', pDevice, '', pPort, MAX_PATH);
// lStrCpy(pPort, @pPort[lStrLen(pPort) + 2]);
else
label2.Caption := '端 口：' + StrPas(pPort);
//label2.Caption := 'Driver := ' + StrPas(pDriver);
except
label1.Caption := '打印机：没有安装打印机';
label2.Caption := '端 口：没有安装打钱机';
end;
FreeMem(pDevice, cchDeviceName);
FreeMem(pDriver, MAX_PATH);
FreeMem(pPort, MAX_PATH);
end;
是取出的pDevice有问题！

大家帮帮心啊，替我看看啊？还有什么另外的方法？

我也看看

procedure TForm1.Button2Click(Sender: TObject);
var
pDevice : pChar;
pDriver : pChar;
pPort : pChar;
hDMode : THandle;
begin
if PrintDialog1.Execute then
begin
GetMem(pDevice, cchDeviceName);
GetMem(pDriver, MAX_PATH);
GetMem(pPort, MAX_PATH);
Printer.GetPrinter(pDevice, pDriver, pPort, hDMode);
if lStrLen(pDriver) = 0 then
begin
GetProfileString('Devices', pDevice, '', pDriver, MAX_PATH);
pDriver[pos(',', pDriver) - 1] := #0;
end;
if lStrLen(pPort) = 0 then
begin
GetProfileString('Devices', pDevice, '', pPort, MAX_PATH);
lStrCpy(pPort, @pPort[lStrLen(pPort)+2]);
end;
Memo1.Lines.Add('Device := ' + StrPas(pDevice));
Memo1.Lines.Add('Driver := ' + StrPas(pDriver));
Memo1.Lines.Add('Port := ' + StrPas(pPort));
FreeMem(pDevice, cchDeviceName);
FreeMem(pDriver, MAX_PATH);
FreeMem(pPort, MAX_PATH);