C# Definition:

       /// <summary>
       /// Contains an array of NIC information
       /// </summary>
       [StructLayout(LayoutKind.Sequential)]
       public struct WLAN_INTERFACE_INFO_LIST
       {
        /// <summary>
        /// Length of <see cref="InterfaceInfo"/> array
        /// Contains an array of NIC information
        /// </summary>
        public Int32 dwNumberOfItems;
        /// <summary>
        /// This member is not used by the wireless service. Applications can use this member when processing individual interfaces.
        /// </summary>
        public Int32 dwIndex;
        /// <summary>
        /// Array of WLAN interfaces.
        /// </summary>
        public WLAN_INTERFACE_INFO[] InterfaceInfo;
        [StructLayout(LayoutKind.Sequential)]
        public struct WLAN_INTERFACE_INFO_LIST
        {
        /// <summary>
        /// Length of <see cref="InterfaceInfo"/> array
        /// </summary>
        public Int32 dwNumberOfItems;
        /// <summary>
        /// This member is not used by the wireless service. Applications can use this member when processing individual interfaces.
        /// </summary>
        public Int32 dwIndex;
        /// <summary>
        /// Array of WLAN interfaces.
        /// </summary>
        public WLAN_INTERFACE_INFO[] InterfaceInfo;

        /// <summary>
        /// Constructor for WLAN_INTERFACE_INFO_LIST.
        /// Constructor is needed because the InterfaceInfo member varies based on how many adapters are in the system.
        /// </summary>
        /// <param name="pList">the unmanaged pointer containing the list.</param>
        public WLAN_INTERFACE_INFO_LIST(IntPtr pList)
        {
        // The first 4 bytes are the number of WLAN_INTERFACE_INFO structures.
        dwNumberOfItems = Marshal.ReadInt32(pList, 0);
        /// <summary>
        /// Constructor for WLAN_INTERFACE_INFO_LIST.
        /// Constructor is needed because the InterfaceInfo member varies based on how many adapters are in the system.
        /// </summary>
        /// <param name="pList">the unmanaged pointer containing the list.</param>
        public WLAN_INTERFACE_INFO_LIST(IntPtr pList)
        {
            // The first 4 bytes are the number of WLAN_INTERFACE_INFO structures.
            dwNumberOfItems = Marshal.ReadInt32(pList, 0);

        // The next 4 bytes are the index of the current item in the unmanaged API.
        dwIndex = Marshal.ReadInt32(pList, 4);
            // The next 4 bytes are the index of the current item in the unmanaged API.
            dwIndex = Marshal.ReadInt32(pList, 4);

        // Construct the array of WLAN_INTERFACE_INFO structures.
        InterfaceInfo = new WLAN_INTERFACE_INFO[dwNumberOfItems];
            // Construct the array of WLAN_INTERFACE_INFO structures.
            InterfaceInfo = new WLAN_INTERFACE_INFO[dwNumberOfItems];

        for (int i = 0; i <= dwNumberOfItems- 1; i++) {
            // The offset of the array of structures is 8 bytes past the beginning.
            // Then, take the index and multiply it by the number of bytes in the
            // structure.
            // The length of the WLAN_INTERFACE_INFO structure is 532 bytes - this
            // was determined by doing a Marshall.SizeOf(WLAN_INTERFACE_INFO)
            IntPtr pItemList = new IntPtr(pList.ToInt64() + (i * 532) + 8);
            for (int i = 0; i < dwNumberOfItems; i++)
            {
            // The offset of the array of structures is 8 bytes past the beginning. Then, take the index and multiply it by the number of bytes in the structure.
            // the length of the WLAN_INTERFACE_INFO structure is 532 bytes - this was determined by doing a sizeof(WLAN_INTERFACE_INFO) in an unmanaged C++ app.
            IntPtr pItemList = new IntPtr(pList.ToInt32() + (i * 532) + 8);

            // Construct the WLAN_INTERFACE_INFO structure, marshal the unmanaged
            // structure into it, then copy it to the array of structures.
            InterfaceInfo[i] = (WLAN_INTERFACE_INFO)Marshal.PtrToStructure(pItemList, typeof(WLAN_INTERFACE_INFO));
        }
       }
      }

            // Construct the WLAN_INTERFACE_INFO structure, marshal the unmanaged structure into it, then copy it to the array of structures.
            WLAN_INTERFACE_INFO wii = new WLAN_INTERFACE_INFO();
            wii = (WLAN_INTERFACE_INFO)Marshal.PtrToStructure(pItemList, typeof(WLAN_INTERFACE_INFO));
            InterfaceInfo[i] = wii;
            }
        }
        }

VB Definition:

     <StructLayout(LayoutKind.Sequential)> _
    Private Structure WLAN_INTERFACE_INFO_LIST
    Public dwNumberofItems As Int32
    Public dwIndex As Int32
    Public InterfaceInfo As WLAN_INTERFACE_INFO()
     Public Structure WLAN_INTERFACE_INFO_LIST
     Public dwNumberOfItems As Int32
     Public dwIndex As Int32
     Public InterfaceInfo As WLAN_INTERFACE_INFO()

     ''' <summary>
     ''' Constructor for WLAN_INTERFACE_INFO_LIST.
     ''' Constructor is needed because the InterfaceInfo member varies based on how many adapters are in the system.
     ''' </summary>
     ''' <param name="pList">the unmanaged pointer containing the list.</param>
     Public Sub New(ByVal pList As IntPtr)
         ' The first 4 bytes are the number of WLAN_INTERFACE_INFO structures.
         dwNumberOfItems = Marshal.ReadInt32(pList, 0)

         ' The next 4 bytes are the index of the current item in the unmanaged API.
         dwIndex = Marshal.ReadInt32(pList, 4)

         ' Construct the array of WLAN_INTERFACE_INFO structures.
         InterfaceInfo = New WLAN_INTERFACE_INFO(dwNumberOfItems - 1) {}

         For i As Integer = 0 To dwNumberOfItems - 1
         ' The offset of the array of structures is 8 bytes past the beginning. Then, take the index and multiply it by the number of bytes in the structure.
         ' the length of the WLAN_INTERFACE_INFO structure is 532 bytes - this was determined by doing a sizeof(WLAN_INTERFACE_INFO) in an unmanaged C++ app.
         Dim pItemList As New IntPtr(pList.ToInt32() + (i * 532) + 8)

         ' Construct the WLAN_INTERFACE_INFO structure, marshal the unmanaged structure into it, then copy it to the array of structures.
         Dim wii As New WLAN_INTERFACE_INFO()
         wii = DirectCast(Marshal.PtrToStructure(pItemList, GetType(WLAN_INTERFACE_INFO)), WLAN_INTERFACE_INFO)
         InterfaceInfo(i) = wii
         Next
     End Sub
     End Structure

User-Defined Field Types:

WLAN_INTERFACE_INFO

    Public Sub New(pList As IntPtr)
        ' The first 4 bytes are the number of WLAN_INTERFACE_INFO structures.
        dwNumberofItems = Marshal.ReadInt32(pList, 0)

Notes:

The constructor of this structure "unmarshal" WLAN_INTERFACE_INFO_LIST data obtained by calling WlanEnumInterfaces(). This is a good example on how to marshal pointer-to-pointer case in C++ world ( kind of confusing because in C# or Managed Environment more broadly, it is just reference, so as you can see from the implementation for C#, it is to be treated like just a single pointer case. Also, this example shows how to handle an array for the InterfaceInfo inside of this structure. It needs two level of marshaling and this example shows that.

        ' The next 4 bytes are the index of the current item in the unmanaged API.
        dwIndex = Marshal.ReadInt32(pList, 4)

        ' Construct the array of WLAN_INTERFACE_INFO structures.
        InterfaceInfo = New WLAN_INTERFACE_INFO(dwNumberofItems - 1) {}

        For i As Integer = 0 To dwNumberofItems - 1
        ' The offset of the array of structures is 8 bytes past the beginning.
        ' Then, take the index and multiply it by the number of bytes in the
        ' structure.
        ' The length of the WLAN_INTERFACE_INFO structure is 532 bytes - this
        ' was determined by doing a Marshall.SizeOf(WLAN_INTERFACE_INFO)
        Dim pItemList As New IntPtr(pList.ToInt64() + (i * 532) + 8)

        ' Construct the WLAN_INTERFACE_INFO structure, marshal the unmanaged
        ' structure into it, then copy it to the array of structures.
        InterfaceInfo(i) = DirectCast(Marshal.PtrToStructure(pItemList, GetType(WLAN_INTERFACE_INFO)), WLAN_INTERFACE_INFO)
        Next
    End Sub

    End Structure

User-Defined Field Types:

WLAN_INTERFACE_INFO

Notes:

The constructor of this structure "unmarshal" WLAN_INTERFACE_INFO_LIST data obtained by calling WlanEnumInterfaces(). This is a good example on how to marshal pointer-to-pointer case in C++ world ( kind of confusing because in C# or Managed Environment more broadly, it is just reference, so as you can see from the implementation for C#, it is to be treated like just a single pointer case. Also, this example shows how to handle an array for the InterfaceInfo inside of this structure. It needs two level of marshaling and this example shows that.

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