错误指针参数未指向可访问的内存

Question

我使用CEN XFS标准构建应用程序，然后我在CEN XFS文档中出现此错误WFS_ERR_INVALID_POINTER它的含义如此A pointer parameter does not point to accessible memory.但我不知道这个错误是什么，

我的WFSExecute像这样：

WFSExecute(lphService, 1401, cardDispense, 0, lppResult);

和我的lppResult一样：

    [StructLayout(LayoutKind.Explicit), Serializable]
    public struct WFSResult
    {
        [FieldOffset(0), MarshalAs(UnmanagedType.U4)]
        public uint RequestID;

        [FieldOffset(4), MarshalAs(UnmanagedType.U2)]
        public ushort hService;

        [FieldOffset(6), MarshalAs(UnmanagedType.Struct, SizeConst = 16)]
        public Timestamp tsTimestamp;

        [FieldOffset(22), MarshalAs(UnmanagedType.U4)]
        public int hResult;

        [FieldOffset(26), MarshalAs(UnmanagedType.U4)]
        public UInt32 dwCommandCode;

        [FieldOffset(26), MarshalAs(UnmanagedType.U4)]
        public UInt32 dwEventID;

        [FieldOffset(30), MarshalAs(UnmanagedType.U4)]
        public Int32 lpBuffer;
    }