Cluster Management APIs in C Sharp

Question

Hello All, Im Coding cluster Management functions in C# using the APIs. When I am trying to DLLImport for the API GetClusterGroupState as I get an System.AccessViolationException that protected memory is accesses. Let me know the How shoud I use this API in c#. Here is my code. [DllImport("clusapi.dll", EntryPoint = "GetClusterGroupState", SetLastError = true, CharSet = CharSet.Unicode, ExactSpelling = false, CallingConvention = CallingConvention.StdCall), SuppressUnmanagedCodeSecurityAttribute()] internal static extern int GetClusterGroupState( IntPtr hClusGroup, out string strOwnerNode, [MarshalAs(UnmanagedType.I4)] int nNodeNamebuf); Thanks