COM Ports im System auslesen

[christian.noeding]

Hallo,


ich hatte die Hilfsfunktionen vergessen zu posten. Damit nicht wieder was fehlt habe ich habe mal ein Beispielprogramm programmiert und an diesen Post angehängt, damit du siehst, wie die einzelnen Funktionen funktionieren...

hier nochmal der benötigte Code:


Benötigte Dateien:

Delphi-Quellcode:

uses
  JwaWinType, SetupApi, Cfg, CfgMgr32

Hilfsfunktionen:

Delphi-Quellcode:

// Delphi wrapper for CM_Get_Device_ID

function GetDeviceID(Inst: DEVINST): string;
var
  Buffer: PTSTR;
  Size: ULONG;
begin
  CM_Get_Device_ID_Size(Size, Inst, 0);
  // Required! See DDK help for CM_Get_Device_ID
  Inc(Size);
  Buffer := AllocMem(Size * SizeOf(TCHAR));
  CM_Get_Device_ID(Inst, Buffer, Size, 0);
  Result := Buffer;
  FreeMem(Buffer);
end;

// Delphi wrapper for SetupDiGetDeviceRegistryProperty

function GetRegistryPropertyString(PnPHandle: HDEVINFO; const DevData: TSPDevInfoData; Prop: DWORD): string;
var
  BytesReturned: DWORD;
  RegDataType: DWORD;
  Buffer: array [0..1023] of TCHAR;
begin
  BytesReturned := 0;
  RegDataType := 0;
  Buffer[0] := #0;
  SetupDiGetDeviceRegistryProperty(PnPHandle, DevData, Prop,
    RegDataType, PByte(@Buffer[0]), SizeOf(Buffer), BytesReturned);
  Result := Buffer;
end;

function ExtractBus(DeviceID: string): string;
begin
  Result := Copy(DeviceID, 1, Pos('\', DeviceID) - 1);
end;

Suchen und Finden der COM-Ports im FormCreate:

Delphi-Quellcode:

procedure TForm1.FormCreate(Sender: TObject);
const
  GUID_DEVINTERFACE_COMPORT: TGUID                = '{86e0d1e0-8089-11d0-9ce4-08003e301f73}';
  GUID_DEVINTERFACE_SERENUM_BUS_ENUMERATOR: TGUID = '{4D36E978-E325-11CE-BFC1-08002BE10318}';
var
  PnPHandle: HDEVINFO;
  DevData: TSPDevInfoData;
  DeviceInterfaceData: TSPDeviceInterfaceData;
  FunctionClassDeviceData: PSPDeviceInterfaceDetailData;
  Success: LongBool;
  Devn: Integer;
  BytesReturned: DWORD;
  SerialGUID: TGUID;
  Inst: DEVINST;
  RegKey: HKEY;
  RegBuffer: array [0..1023] of Char;
  RegSize, RegType: DWORD;
  FriendlyName: string;
  PortName: string;
  DeviceDescription: string;
  Bus: string;

  TestHandle : integer;
  i:integer;
begin
  // these API conversions are loaded dynamically by default
  LoadSetupApi;
  LoadConfigManagerApi;

  // enumerate all serial devices (COM port devices)
    SerialGUID := GUID_DEVINTERFACE_COMPORT; // GUID_DEVINTERFACE_SERENUM_BUS_ENUMERATOR;
  PnPHandle := SetupDiGetClassDevs(@SerialGUID, nil, 0, DIGCF_PRESENT or DIGCF_DEVICEINTERFACE);
  if PnPHandle = Pointer(INVALID_HANDLE_VALUE) then
    Exit;
  Combobox1.Items.BeginUpdate;
  Combobox1.Items.Clear;
  Devn := 0;
  repeat
    DeviceInterfaceData.cbSize := SizeOf(TSPDeviceInterfaceData);
    Success := SetupDiEnumDeviceInterfaces(PnPHandle, nil, SerialGUID, Devn, DeviceInterfaceData);
    if Success then
    begin
      DevData.cbSize := SizeOf(DevData);
      BytesReturned := 0;
      // get size required for call
      SetupDiGetDeviceInterfaceDetail(PnPHandle, @DeviceInterfaceData, nil, 0, BytesReturned, @DevData);
      if (BytesReturned <> 0) and (GetLastError = ERROR_INSUFFICIENT_BUFFER) then
      begin
        // allocate buffer and initialize it for call
        FunctionClassDeviceData := AllocMem(BytesReturned);
        FunctionClassDeviceData.cbSize := SizeOf(TSPDeviceInterfaceDetailData);

        if SetupDiGetDeviceInterfaceDetail(PnPHandle, @DeviceInterfaceData,
          FunctionClassDeviceData, BytesReturned, BytesReturned, @DevData) then
        begin
          // gives the friendly name of the device as shown in Device Manager
          FriendlyName := GetRegistryPropertyString(PnPHandle, DevData, SPDRP_FRIENDLYNAME);
          // gives a device description
          DeviceDescription := GetRegistryPropertyString(PnPHandle, DevData, SPDRP_DEVICEDESC);
          // now try to get the assigned COM port name
          RegKey := SetupDiOpenDevRegKey(PnPHandle, DevData, DICS_FLAG_GLOBAL, 0, DIREG_DEV, KEY_READ);
          RegType := REG_SZ;
          RegSize := SizeOf(RegBuffer);
          RegQueryValueEx(RegKey, 'PortName', nil, @RegType, @RegBuffer[0], @RegSize);
          RegCloseKey(RegKey);
          PortName := RegBuffer;
          Inst := DevData.DevInst;
          CM_Get_Parent(Inst, Inst, 0);
          Bus := ExtractBus(GetDeviceID(Inst));
          Combobox1.Items.Add(PortName + ' (' + DeviceDescription + ', ' + Bus+')');
        end;
        FreeMem(FunctionClassDeviceData);
      end;
    end;
    Inc(Devn);
  until not Success;
  SetupDiDestroyDeviceInfoList(PnPHandle);
  Combobox1.Items.EndUpdate;

  // unload API conversions
  UnloadSetupApi;
  UnloadConfigManagerApi;

  Combobox2.Clear;
  for i:=1 to 16 do
  begin
    TestHandle := CreateFile(PChar('\\.\COM'+IntToStr(i)),GENERIC_READ or GENERIC_WRITE,0,nil,OPEN_EXISTING,FILE_FLAG_OVERLAPPED,LongInt(0));
    if (TestHandle > 0) then
    begin
      Combobox2.Items.Add('COM'+inttostr(i));
      CloseHandle(TestHandle);
    end;
  end;

  Combobox1.itemindex:=0;
  Combobox2.itemindex:=0;
end;

ciao,
Christian