c#接受c++动态数组指针

简述

c#定义数组或向量传递指针参数，c++算法向数组指针输出参数数据

内容

[System.Runtime.InteropServices.DllImport(@"NativeLib.dll",

           EntryPoint = "MthCopy",

            CharSet = System.Runtime.InteropServices.CharSet.Ansi,

            CallingConvention = System.Runtime.InteropServices.CallingConvention.StdCall)]

private static extern int MthCopy(byte[] Source, ref IntPtr Trans, int Len);

[System.Runtime.InteropServices.DllImport(@"NativeLib.dll",


            EntryPoint = "MthPtrArrayFree",


            CharSet = System.Runtime.InteropServices.CharSet.Ansi,


            CallingConvention = System.Runtime.InteropServices.CallingConvention.StdCall)]


private static extern int MthPtrArrayFree(IntPtr PtrArray);

调用代码：

int Len = 4;

byte[] Source = new byte[] { 1, 2, 3, 4 };

IntPtr Trans = IntPtr.Zero;
         
MthCopy(Source, ref Trans, 4);

byte[] TransArr = new byte[Len];

//复制或者用unsafe直接访问指针

System.Runtime.InteropServices.Marshal.Copy(Trans, TransArr, 0, TransArr.Length);

MthPtrArrayFree(Trans);

c++ dll

 

extern "C" __declspec(dllexport)  int__stdcall MthCopy(BYTE *Source, BYTE *&Trans, int Len);

extern "C" __declspec(dllexport)  int__stdcall MthPtrArrayFree(void *PtrArray);

int MthCopy(BYTE *Source, BYTE *&Trans, int Len)

{

	Trans = new BYTE[Len];

	memcpy_s(Source, Len, Trans, Len);

}

int MthPtrArrayFree(void *PtrArray)

{

	if (PtrArray)

	{

  delete[] PtrArray;

  PtrArray = nullptr;

	}

	return 0;

}

c++ dll例2

extern "C" __declspec(dllexport)  int__stdcall MthCopy(BYTE *Source, BYTE *&Trans, int Len);
extern "C" __declspec(dllexport)  int__stdcall MthPtrArrayFree(void *PtrArray);
int MthCopy(BYTE *Source, BYTE *&Trans, int Len)
{
	Trans = new BYTE[Len];
	memcpy_s(Source, Len, Trans, Len);
}

int MthPtrArrayFree(void *PtrArray)
{
	if (PtrArray)
	{
  delete[] PtrArray;
  PtrArray = nullptr;
	}
	return 0;
}