C# Signature:

    [DllImport("Iphlpapi.dll", CharSet = CharSet.Auto)]
    public static extern int IpReleaseAddress(ref IP_ADAPTER_INDEX_MAP AdapterInfo);

User-Defined Types:

None.

Alternative Managed API:

Do you know one? Please contribute it!

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

The following C# sourcecode implements classes and structures with the purpose of making the use of GetInterfaceInfo and IpReleaseAddress easier. Thanks to Lieutenant (http://www.red-gate.com/MessageBoard/viewtopic.php?t=5754) for submitting this code.

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public struct IP_ADAPTER_INDEX_MAP
    {
    public int Index;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = PInvokes.MAX_ADAPTER_NAME)]
    public String Name;
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public struct IP_INTERFACE_INFO
    {
    public int NumAdapters;
    public IP_ADAPTER_INDEX_MAP[] Adapter;

    public static IP_INTERFACE_INFO FromByteArray(Byte[] buffer)
    {
    unsafe
    {
        IP_INTERFACE_INFO rv = new IP_INTERFACE_INFO();
        int iNumAdapters = 0;
        Marshal.Copy(buffer, 0, new IntPtr(&iNumAdapters), 4);
        IP_ADAPTER_INDEX_MAP[] adapters = new IP_ADAPTER_INDEX_MAP[iNumAdapters];
        rv.NumAdapters = iNumAdapters;
        rv.Adapter = new IP_ADAPTER_INDEX_MAP[iNumAdapters];
        int offset = sizeof(int);
        for (int i = 0; i < iNumAdapters; i++)
        {
        IP_ADAPTER_INDEX_MAP map = new IP_ADAPTER_INDEX_MAP();
        IntPtr ptr = Marshal.AllocHGlobal(Marshal.SizeOf(map));
        Marshal.StructureToPtr(map, ptr, false);
        Marshal.Copy(buffer, offset, ptr, Marshal.SizeOf(map));
        map = (IP_ADAPTER_INDEX_MAP)Marshal.PtrToStructure(ptr, typeof(IP_ADAPTER_INDEX_MAP));
        Marshal.FreeHGlobal(ptr);
        rv.Adapter[i] = map;
        offset += Marshal.SizeOf(map);
        }
        return rv;
     }
    }
    }

    internal class PInvokes
    {
    public const int MAX_ADAPTER_NAME = 128;

    public const int ERROR_INSUFFICIENT_BUFFER = 122;
    public const int ERROR_SUCCESS = 0;

    [DllImport("Iphlpapi.dll", CharSet = CharSet.Auto)]
    public static extern int GetInterfaceInfo(Byte[] PIfTableBuffer, ref int size);

    [DllImport("Iphlpapi.dll", CharSet = CharSet.Auto)]
    public static extern int IpReleaseAddress(ref IP_ADAPTER_INDEX_MAP AdapterInfo);
    }

    public class Iphlpapi
    {
    public static IP_INTERFACE_INFO GetInterfaceInfo()
    {
    int size = 0;
    int r = PInvokes.GetInterfaceInfo(null, ref size);
    Byte[] buffer = new Byte[size];
    r = PInvokes.GetInterfaceInfo(buffer, ref size);
    if (r != PInvokes.ERROR_SUCCESS)
        throw new Exception("GetInterfaceInfo returned an error.");
    IP_INTERFACE_INFO info = IP_INTERFACE_INFO.FromByteArray(buffer);
    return info;
    }

    public static bool IpReleaseAddress(IP_ADAPTER_INDEX_MAP adapter)
    {
    if (PInvokes.IpReleaseAddress(ref adapter) == PInvokes.ERROR_SUCCESS)
        return true;
    else
        return false;
    }

    public static void IpReleaseAllAddresses()
    {
    IP_INTERFACE_INFO info = GetInterfaceInfo();
    for (int i = 0; i < info.NumAdapters; i++)
        IpReleaseAddress(info.Adapter[i]);
    }
    }

Please edit this page!

Do you have...

• helpful tips or sample code to share for using this API in managed code?
• corrections to the existing content?
• variations of the signature you want to share?
• additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).