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c# 调用C++ 结构体指针的问题: 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

问题:c++ 结构体: typedef struct _vehicles_info { int idx; /* * 车牌号码 */ char vehicle_name[32]; /* * rtsp信息 */ char vehicle_rtsp[256]; //0 offline, 1 online Byte status; }VehicleInfo; 方法:int GetVehiclesInfo(VehicleInfo *pVehicle, int size); 转为C#方法后的代码如下: [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)] public unsafe struct VehicleInfo { public int idx; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] public string vehicle_name;//车牌号码 [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 256)] public string vehicle_rtsp;//rtsp信息 public byte bstatus;//0 offline, 1 online }; 方法: [DllImport("UserClient.dll", CallingConvention = CallingConvention.Cdecl)] public unsafe static extern int GetVehiclesInfo(IntPtr[] p, int size); 调用代码如下: IntPtr[] record = new IntPtr[isize]; //申请内存空间 record[0] = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(BwsPtzManager.VehicleInfo)) * isize); int realcount = BwsPtzManager.GetVehiclesInfo(record, isize); for (int i = 0; i < realcount; i++) { BwsPtzManager.VehicleInfo vehinfo = new BwsPtzManager.VehicleInfo(); vehinfo = (BwsPtzManager.VehicleInfo)Marshal.PtrToStructure((IntPtr)((UInt32)record[i]), typeof(BwsPtzManager.VehicleInfo)); Marshal.FreeHGlobal(record[i]); } 问题来了:代码运行到 vehinfo = (BwsPtzManager.VehicleInfo)Marshal.PtrToStructure((IntPtr)((UInt32)record[i]), typeof(BwsPtzManager.VehicleInfo)); 这里的时候,总是报 “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”的错误,求大神指点。已经折腾的快挂了。总找不到原因。 另附c++代码如下: VehicleInfo *pVehicle = (VehicleInfo*)malloc(sizeof(VehicleInfo)*count) ; memset(pVehicle, 0x00, sizeof(VehicleInfo)*count); int realcount = GetVehiclesInfo(pVehicle, count); printf("%d\n", realcount); for(int i = 0; i < realcount; i++) { printf("%s,%s,%d\n", pVehicle[i].vehicle_name,pVehicle[i].vehicle_rtsp,pVehicle[i].status ); } 运行一切正常,没任何问题。神救救我吧
追问:首先很感谢您的回答,很详细.我还有个疑问
int GetVehiclesInfo(VehicleInfo *pVehicle, int size); 
这个接口既然有问题的话,C++代码调用为何没有问题呢?因为这个接口不是我写的,所以要让别人改接口,必须证明他这个写法确实是错的.
其他:你只申请了record[0]的空间,1~isize的空间没有申请,使用使为默认值(null)肯定出问题了 

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