C#

[DllImport("user32.dll", CharSet = CharSet.Auto)]<br />
        public static extern IntPtr RegisterDeviceNotification(IntPtr hRecipient, DEV_BROADCAST_DEVICEINTERFACE NotificationFilter, UInt32 Flags);<br />
<br />
        [DllImport("user32.dll", CharSet = CharSet.Auto)]<br />
        public static extern uint UnregisterDeviceNotification(IntPtr hHandle);<br />
<br />
        [DllImport("setupapi.dll", SetLastError = true)]<br />
        public static extern IntPtr SetupDiGetClassDevs(ref Guid gClass, UInt32 iEnumerator, IntPtr hParent, UInt32 nFlags);

List< string > HWList = new List< string >();

public list< string > getAll()
{
 Guid myGUID = System.Guid.Empty;
                IntPtr hDevInfo = Native.SetupDiGetClassDevs(ref myGUID, 0, IntPtr.Zero, Native.DIGCF_ALLCLASSES | Native.DIGCF_PRESENT);

                if (hDevInfo.ToInt32() == Native.INVALID_HANDLE_VALUE)
                {
                    throw new Exception("Invalid Handle");
                }
                Native.SP_DEVINFO_DATA DeviceInfoData;
                DeviceInfoData = new Native.SP_DEVINFO_DATA();
                DeviceInfoData.cbSize = 28;
                //is devices exist for class
                DeviceInfoData.devInst = 0;
                DeviceInfoData.classGuid = System.Guid.Empty;
                DeviceInfoData.reserved = 0;
                UInt32 i;
                StringBuilder DeviceName = new StringBuilder("");
                DeviceName.Capacity = Native.MAX_DEV_LEN;
                for (i = 0; Native.SetupDiEnumDeviceInfo(hDevInfo, i, DeviceInfoData); i++)
                {
                    //Declare vars
                    while (!Native.SetupDiGetDeviceRegistryProperty(hDevInfo,
                                                                    DeviceInfoData,
                                                                    Native.SPDRP_DEVICEDESC,
                                                                    0,
                                                                    DeviceName,
                                                                    Native.MAX_DEV_LEN,
                                                                    IntPtr.Zero))
                    {
                        //Skip
                    }
                    HWList.Add(DeviceName.ToString());
                }
}

g_amol wrote:

excel open error "no overload for method Open takes 13 arguements"

George_George wrote:

But I am not sure whether I am correct.

delegate int Foo(string bar);

int Bar(string foo)
{
  return 0;
}

using System;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int i = 0;
            i = i.ToMax(); //pointless example : i = int.MaxValue
            Console.Write(i);
            Console.Read();
        }
    }
    public static class Extensions
    {
        public static int ToMax(this int i)
        {
            i = int.MaxValue;
            return i;
        }
    }
}