c# 调用C/C++ DLL，传入返回结构体以及指针数组(指针指向自定的结构体)

1 定义结构体

1-1 C++代码：

定义结构体

struct DetectInfo {int x; //!< x coordinate of the top-left cornerint y; //!< y coordinate of the top-left cornerint width; //!< width of the rectangleint height; //!< height of the rectangle;float conf;int class_id;
};

1-2 C# 代码：

 [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]public struct DetectInfo{// [MarshalAs(UnmanagedType.LPStr)]public int x; //!< x coordinate of the top-left cornerpublic int y;  //!< y coordinate of the top-left cornerpublic int width; //!< width of the rectanglepublic int height; //!< height of the rectangle;public float conf; // confidence score public int class_id; // class id}

2 返回结构体

2-1 C++代码：

头文件声明

extern "C" APPEARANCEDETECTALG_EXPORTS struct DetectInfo simpleStruct();

函数实现

ALG_EXPORTS struct DetectInfo simpleStruct() {DetectInfo dInfo;dInfo.x = 1;dInfo.y = 2;dInfo.width = 3;dInfo.height = 4;dInfo.conf = 0.56;dInfo.class_id = 7;return dInfo;
}

2-2 C# 代码：

[DllImport("APPEARANCEDETECTALGDLL.dll", CallingConvention = CallingConvention.Cdecl)]
extern static DetectInfo simpleStruct();// 返回 结构体
DetectInfo ddInfo = simpleStruct();
Console.WriteLine("{0}, {1}, {2}, {3}, {4}, {5}", ddInfo.x, ddInfo.y, ddInfo.width, ddInfo.height, ddInfo.conf, ddInfo.class_id);Console.ReadLine();

3 传入返回指针数组

3-1 C++代码：

头文件声明

extern "C" ALG_EXPORTS int simpleStructList(int num, DetectInfo* dInfoList);

函数实现

ALG_EXPORTS int simpleStructList(int num, DetectInfo* dInfoList) {DetectInfo dInfo;for (int i = 0; i < 10; ++i){dInfo.x = i;dInfo.y = i;dInfo.width = i;dInfo.height = i;dInfo.conf = 0.56 / i;dInfo.class_id = i;*(dInfoList + i) = dInfo;}return 0;
}

3-2 C# 代码：

[DllImport("ALGDLL.dll", CallingConvention = CallingConvention.Cdecl)]
extern static int simpleStructList(int num, [In, Out] DetectInfo[] dInfoList);// 传入和返回 结构体
const int nCount = 100;
DetectInfo[] dInfoList = new DetectInfo[nCount];int rst = simpleStructList(nCount, dInfoList);for (int i = 0; i < rst; i++)
{Console.WriteLine("{0}, {1}, {2}, {3}, {4}, {5}", dInfoList[i].x, dInfoList[i].y, dInfoList[i].width, dInfoList[i].height, dInfoList[i].conf, dInfoList[i].class_id);
}
Console.ReadLine();