C# 调用C++dll的参数为数据结构指针的指针

[EasonLouis]

C++的dll

HRESULT extern WINAPI WFSGetInfo ( HSERVICE hService, DWORD dwCategory, LPVOID lpQueryDetails, DWORD dwTimeOut, LPWFSRESULT * lppResult);

结构体

typedef struct _wfs_result
	{
		REQUESTID RequestID;
		HSERVICE hService;
		SYSTEMTIME tsTimestamp;
		HRESULT hResult;
		union {
			DWORD dwCommandCode;
			DWORD dwEventID;
		} u;
		LPVOID lpBuffer;
	} WFSRESULT, * LPWFSRESULT;
typedef struct _wfs_idc_status
{
WORD	fwDevice;
WORD	fwMedia;
WORD	fwRetainBin; 
WORD	fwSecurity; 
USHORT usCards;
WORD	fwChipPower; 
LPSTR	lpszExtra;
} WFSIDCSTATUS, *LPWFSIDCSTATUS;

c#的定义

      [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
      public struct WFSRESULT1
        {
            public UInt32 RequestID;
            public ushort hService;
            public _SYSTEMTIME tsTimestamp;//对应下面的 _SYSTEMTIME
            public int hResult;
            public AnonymousStruct U;//对应下面的 AnonymousStruct 结构
            public IntPtr lpBuffer;//返回的指针，指向_wfs_idc_status 这个结构
        }
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        public struct LPStruct
        {
            public IntPtr ptrWFSRESULT;//返回的指针，指向WFSRESULT1 这个结构
        }
      [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        public struct _wfs_idc_status
        {
            public UInt16 fwDevice;
            public UInt16 fwMedia;
            public UInt16 fwRetainBin;
            public UInt16 fwSecurity;
            public ushort usCards;
            public UInt16 fwChipPower;
            [MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 999)]
            public string lpszExtra;
        }
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        public struct _SYSTEMTIME
        {
            public UInt16 wYear;
            public UInt16 wMonth;
            public UInt16 wDayOfWeek;
            public UInt16 wDay;
            public UInt16 wHour;
            public UInt16 wMinute;
            public UInt16 wSecond;
            public UInt16 wMilliseconds;
        }
        [DllImport("msxfs.dll", CharSet = CharSet.Ansi)]
        public static extern int WFSGetInfo(int iService, int iCategory, string sQueryDetail, int iTimeOut, ref IntPtr ptr);

C#执行

            LPStruct lpStruct = new LPStruct();
            IntPtr ptr = Marshal.AllocHGlobal(Marshal.SizeOf(lpStruct));
            Marshal.StructureToPtr(lpStruct, ptr, false);
            int iRet = WFSGetInfo(m_service, WFS_INF_IDC_STATUS, null, 2000, ref ptr);
            lpStruct = (LPStruct)Marshal.PtrToStructure(ptr, typeof(LPStruct));
            WFSRESULT1 wfsR1;
            wfsR1 = (WFSRESULT1)Marshal.PtrToStructure(lpStruct.ptrWFSRESULT, typeof(WFSRESULT1));//运行会在Application.Run()里面报错"未处理AccessViolationException。尝试读取或写入受保护的内存。这通常指示其他内存已损坏。"
            _wfs_idc_status stat1 = (_wfs_idc_status)Marshal.PtrToStructure(wfsR1.lpBuffer, typeof(_wfs_idc_status));

请求各位高手指教，是我定义和操作结构体错误导致的吗？

[EnForGrass]

搞不清楚REQUESTID RequestID; HSERVICE hService; SYSTEMTIME tsTimestamp;这几个是什么

[EnForGrass]

REQUESTID RequestID; HSERVICE hService这两个真不知道是什么类型的，你自己搞定吧

public struct SYSTEMTIME {
    
    /// WORD->unsigned short
    public ushort wYear;
    
    /// WORD->unsigned short
    public ushort wMonth;
    
    /// WORD->unsigned short
    public ushort wDayOfWeek;
    
    /// WORD->unsigned short
    public ushort wDay;
    
    /// WORD->unsigned short
    public ushort wHour;
    
    /// WORD->unsigned short
    public ushort wMinute;
    
    /// WORD->unsigned short
    public ushort wSecond;
    
    /// WORD->unsigned short
    public ushort wMilliseconds;
}
public struct WFSRESULT {
    
    /// short
    public short RequestID;//假如为short
    
    /// short
    public short hService;////假如为short
    
    /// SYSTEMTIME->_SYSTEMTIME
    public SYSTEMTIME tsTimestamp;
    
    /// HRESULT->LONG->int
    public int hResult;

    public System.IntPtr lpBuffer;
}

public struct WFSIDCSTATUS {
    
    /// WORD->unsigned short
    public ushort fwDevice;
    
    /// WORD->unsigned short
    public ushort fwMedia;
    
    /// WORD->unsigned short
    public ushort fwRetainBin;
    
    /// WORD->unsigned short
    public ushort fwSecurity;
    
    /// USHORT->unsigned short
    public ushort usCards;
    
    /// WORD->unsigned short
    public ushort fwChipPower;
    
    /// LPSTR->CHAR*
    [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.LPStr)]
    public string lpszExtra;
}

    [System.Runtime.InteropServices.DllImportAttribute("XXX.dll", EntryPoint="WFSGetInfo")]
public static extern  int WFSGetInfo(short hService, uint dwCategory, System.IntPtr lpQueryDetails, uint dwTimeOut, ref System.IntPtr lppResult) ;

[EasonLouis]

弄好了一半，我上面用LPSTRUCT结构体里的IntPtr ptrWFSRESULT返回的指针，指向WFSRESULT1 这个结构是错的，直接使用WFSRESULT1 结构体就行。修改如下

            WFSRESULT1 wfsR1 = new WFSRESULT1();
            IntPtr ptr = IntPtr.Zero;
            int iRet = WFSGetInfo(m_service, WFS_INF_IDC_STATUS, null, 2000, ref ptr);
            wfsR1 = (WFSRESULT1)Marshal.PtrToStructure(ptr, typeof(WFSRESULT1));

但是之后

             _wfs_idc_status stat1 = new _wfs_idc_status();
            stat1 = (_wfs_idc_status)Marshal.PtrToStructure(wfsR1.lpBuffer, typeof(_wfs_idc_status));

第二行报错"引发类型为“System.ExecutionEngineException”的异常。"。