C # obtain the MAC address of the IP address in the LAN

Using system;
Using system. Collections. Generic;
Using system. componentmodel;
Using system. Data;
Using system. drawing;
Using system. text;
Using system. Windows. forms;

Using system. runtime. interopservices;
Using system. net;

Namespace macapp
{
Public partial class form1: Form
{
[Dllimport ("ws2_32.dll")]
Private Static extern int inet_addr (string CP );
[Dllimport ("iphlpapi. dll")]
Private Static extern int sendarp (int32 destip, int32 srcip, ref int64 pmacaddr, ref int32 phyaddrlen );
Public form1 ()
{
Initializecomponent ();
}

Private void button#click (Object sender, eventargs E)
{
Richtextbox1.text = getmacaddress (textbox1.text); // obtain the MAC address of the remote IP address (cross-network segment not supported)
}
Private string getmacaddress (string hostip) // obtain the MAC address of the remote IP address (cross-network segment not supported)
{
String MAC = "";
Try
{
Int32 ldest = inet_addr (hostip); // convert an IP address from the point format to an unsigned long integer
Int64 macinfo = new int64 ();
Int32 Len = 6;
Sendarp (ldest, 0, ref macinfo, ref Len );
String tmpmac = convert. tostring (macinfo, 16). padleft (12, '0'); // convert it to hexadecimal notation. Note that some do not have 12 digits.
MAC = tmpmac. substring (0, 2). toupper ();//
For (INT I = 2; I <tmpmac. length; I = I + 2)
{
MAC = tmpmac. substring (I, 2). toupper () + "-" + MAC;
}
}
Catch (exception Mye)
{
MAC = "Mac error obtaining remote host:" + Mye. message;
}
Return MAC;
}

Private void form1_load (Object sender, eventargs E)
{
If (DNS. gethostentry (DNS. gethostname (). Addresslist. length> 0)
{
Textbox1.text = DNS. gethostentry (DNS. gethostname (). Addresslist [0]. tostring (); // obtain the local IP Address
}
}
}
}