C++dll的方法为 LPECWATCHDATA WINAPI ecwGetExternsionData(WORD widx);
LPECWATCHDATA是这样定义的
typedef struct {
WORD nState; //状态
WORD nIdx; //索引
WORD wDataCnt; //数据(lpData)项数
char szTime[20]; //时间
unsigned char* lpIDString; //设备号码
unsigned char* lpNameString; //设备/用户名称
LPCTSTR lpData[8];
}ECWATCHDATA,*LPECWATCHDATA; 我在C#里是这样转的 ECWATCHDATAeds = (ECWATCHDATA)(Marshal.PtrToStructure(ecwGetExternsionData(i), typeof(ExteECWATCHDATA))); ExternsionDataStruct是我自己定义的一个结构体,结构体为
[System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, CharSet = System.Runtime.InteropServices.CharSet.Ansi)]
public struct ECWATCHDATA
{ /// WORD->unsigned short
public ushort nState; /// WORD->unsigned short
public ushort nIdx; /// WORD->unsigned short
public ushort wDataCnt; /// char[20]
[System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValTStr, SizeConst = 20)]
public string szTime; /// char*
public IntPtr lpIDString; /// char*
public IntPtr lpNameString; /// char*[8]
[System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValArray, SizeConst = 8, ArraySubType = System.Runtime.InteropServices.UnmanagedType.SysUInt)]
public System.IntPtr[] lpData;
}
ECWATCHDATAeds = (ECWATCHDATA)(Marshal.PtrToStructure(ecwGetExternsionData(i), typeof(ECWATCHDATA))); 转化C#的结构体后里面有的值不对。像lpIDString,lpNameString和实际值对不上,这是什么原因?
LPECWATCHDATA是这样定义的
typedef struct {
WORD nState; //状态
WORD nIdx; //索引
WORD wDataCnt; //数据(lpData)项数
char szTime[20]; //时间
unsigned char* lpIDString; //设备号码
unsigned char* lpNameString; //设备/用户名称
LPCTSTR lpData[8];
}ECWATCHDATA,*LPECWATCHDATA; 我在C#里是这样转的 ECWATCHDATAeds = (ECWATCHDATA)(Marshal.PtrToStructure(ecwGetExternsionData(i), typeof(ExteECWATCHDATA))); ExternsionDataStruct是我自己定义的一个结构体,结构体为
[System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, CharSet = System.Runtime.InteropServices.CharSet.Ansi)]
public struct ECWATCHDATA
{ /// WORD->unsigned short
public ushort nState; /// WORD->unsigned short
public ushort nIdx; /// WORD->unsigned short
public ushort wDataCnt; /// char[20]
[System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValTStr, SizeConst = 20)]
public string szTime; /// char*
public IntPtr lpIDString; /// char*
public IntPtr lpNameString; /// char*[8]
[System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValArray, SizeConst = 8, ArraySubType = System.Runtime.InteropServices.UnmanagedType.SysUInt)]
public System.IntPtr[] lpData;
}
ECWATCHDATAeds = (ECWATCHDATA)(Marshal.PtrToStructure(ecwGetExternsionData(i), typeof(ECWATCHDATA))); 转化C#的结构体后里面有的值不对。像lpIDString,lpNameString和实际值对不上,这是什么原因?
你需要再次使用类似的方法把 IntPtr 转换成你需要的字符串。
https://msdn.microsoft.com/zh-cn/library/7b620dhe(v=vs.110).aspx
使用 C 语言测试一下这个结果。
返回一个结构的指针总归不是一个好的想法。
换成StringBuilder试试看
设定 Pack = 1