Marshal C++ int array to C#

Question

I would like to marshal an array of ints from C++ to C#. I have an unmanaged C++ dll which contains:

DLL_EXPORT int* fnwrapper_intarr()
{
    int* test = new         


        

Answer 1

[DllImport("wrapper_demo_d.dll")]
public static extern IntPtr fnwrapper_intarr();

IntPtr ptr = fnwrapper_intarr();
int[] result = new int[3];
Marshal.Copy(ptr, result, 0, 3);

You need also to write Release function in unmanaged Dll, which deletes pointer created by fnwrapper_intarr. This function must accept IntPtr as parameter.

DLL_EXPORT void fnwrapper_release(int* pArray)
{
    delete[] pArray;
}

[DllImport("wrapper_demo_d.dll")]
public static extern void fnwrapper_release(IntPtr ptr);

IntPtr ptr = fnwrapper_intarr();
...
fnwrapper_release(ptr);

Answer 2

Just to add a tip to Alex F Answer : If you don't know the size of Array it's easy to get,define another dll_export to get the array size.