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public string GetNetworks()
{
    IntPtr x, pInfoList, clientHandle;
    UInt32 a, b, c;

    a = WlanOpenHandle(1, IntPtr.Zero, out x, out clientHandle); // Wlan handle öffnen
    b = WlanEnumInterfaces(clientHandle, IntPtr.Zero, out pInfoList); // Interfaces holen
    c = WlanCloseHandle(clientHandle, IntPtr.Zero); // Handle schliessen


    Console.WriteLine("WlanOpenHandle return code: " + a); // 0 = Okay, kein Fehler
    Console.WriteLine("Client handle: " + clientHandle.ToString());
    Console.WriteLine("WlanEnumInterfaces return code: " + b); // 0 = Okay, kein Fehler
    Console.WriteLine("WlanCloseHandle return code: " + c); // 0 = Okay, kein Fehler

    // offset reading of the structure
    int c_dwNumberOfItems = Marshal.ReadInt32(pInfoList, 0);
    Console.WriteLine("WLAN_INTERFACE_INFO_LIST.dwNumberOfItems: {0}", c_dwNumberOfItems);
    int c_dwIndex = Marshal.ReadInt32(pInfoList, 4);
    Console.WriteLine("WLAN_INTERFACE_INFO_LIST.dwIndex: {0}", c_dwIndex);

    int ifListStartOffset = 8;
    int ifListItemSize = IntPtr.Size + 512 + 4; // IntPtr + WCHAR[256] + Int32

    // GUID
    IntPtr c_InterfaceGuid = Marshal.ReadIntPtr(pInfoList, ifListStartOffset);

    Int32 c_isState = Marshal.ReadInt32(pInfoList, ifListStartOffset + IntPtr.Size + 512);
    Console.WriteLine("Interface state: {0}", c_isState);

    return "Success?";
}

// WlanAPI pInvokes
[StructLayout(LayoutKind.Sequential)]
public struct WLAN_INTERFACE_INFO_LIST
{
    [MarshalAs(UnmanagedType.I4)]
    public int dwNumberOfItems;
    [MarshalAs(UnmanagedType.I4)]
    public int dwIndex;
    [MarshalAs(UnmanagedType.ByValArray)]
    public WLAN_INTERFACE_INFO[] InterfaceInfo;
}

[StructLayout(LayoutKind.Sequential)]
public struct WLAN_INTERFACE_INFO
{
    public IntPtr InterfaceGuid;
    [MarshalAs(UnmanagedType.LPWStr, SizeConst = 256)]
    public String strInterfaceDescription;
    public int isState;
}

[DllImport("wlanapi.dll", SetLastError = true)]
public static extern uint WlanOpenHandle(int dwClientVersion, IntPtr pReserved, out IntPtr pdwNegotiatedVersion, out IntPtr phClientHandle);

[DllImport("wlanapi.dll", SetLastError = true)]
public static extern uint WlanCloseHandle(IntPtr hClientHandle, IntPtr pReserved);

[DllImport("wlanapi.dll", SetLastError = true)]
public static extern uint WlanEnumInterfaces(IntPtr hClientHandle, IntPtr pReserverd, out IntPtr ppInterfaceList);

[DllImport("wlanapi.dll", SetLastError = true)]
private static extern int WlanScan(IntPtr hClientHandle,IntPtr pInterfaceGuid,IntPtr pDot11Ssid, IntPtr pIeData, IntPtr pReserved);