[moo2k]

Сначала продекларируй ф-ции:

Код:

function CM_Get_Device_ID_Size(pulLen: PDWORD; dnDevInst: DWORD; ulFlags: DWORD): DWORD; stdcall; external setupapi;
function CM_Get_Device_IDA(dnDevInst: DWORD; Buffer: PChar; BufferLen: DWORD; ulFlags: DWORD): DWORD; stdcall; external setupapi;

uses .... SetupAPI;

Код:

function IsUSBDevice(DevInst: DWORD): boolean;
  function CompareMem(p1, p2: Pointer; len: DWORD): boolean;
  var
   i: DWORD;
  begin
   result := false;
    if len = 0 then exit;
     for i := 0 to len-1 do
      if PByte(DWORD(p1) + i)^ <> PByte(DWORD(p2) + i)^ then exit;
      result := true;
  end;
var
 IDLen: DWORD;
 ID   : PChar;
 err  : TIniFile;
begin
try
 result := false;
 if (CM_Get_Device_ID_Size(@IDLen, DevInst, 0) <> 0) or (IDLen = 0) then exit;

 inc(IDLen);
 ID := GetMemory(IDLen);

 if ID = nil then exit;

 if (CM_Get_Device_IDA(DevInst, ID, IDLen, 0) <> 0) or (not CompareMem(ID, PChar('USBSTOR'), 7)) then
  begin
   FreeMemory(ID);
   exit;
  end;
 FreeMemory(ID);
 result := true;
except
 err:=TIniFile.Create('C:\usb\Config\Errors.ini');
 err.WriteString('UnknownErrors', 'IsUSBDevice/'+DateToStr(Date)+'/'+TimeToStr(Time), 'Ошибка в функции');
 err.Free;
end;
end;