c# LParam 转结构体获取GUID问题, 苦寻方法望指点

 通过windows 消息机制获取 硬件ID  获取的值是错误的，找了好久也没有c#这块的处理方法   [StructLayout(LayoutKind.Sequential)]
        internal struct DEV_BROADCAST_HDR
        {
            public UInt32 dbch_size;
            public UInt32 dbch_devicetype;
            public UInt32 dbch_reserved;
            public Guid dbch_eventguid;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 128)]
            public char[] dbcp_name;
        }Win32USB_API.DEV_BROADCAST_HDR pHdr = (Win32USB_API.DEV_BROADCAST_HDR)Marshal.PtrToStructure(m.LParam, typeof(Win32USB_API.DEV_BROADCAST_HDR));