code

class Program
{

    [StructLayout(LayoutKind.Sequential)]
    struct ST
    {
        public int a;
        public int b;
        public int c;
    };
    [DllImport("../../Debug/cpp_dll1.dll", EntryPoint = "?Test@@YAXPAUST@@I@Z")]
    unsafe extern static void Test(ST* datas, int count);


    static void Main(string[] args)
    {
        Console.WriteLine(System.Environment.CurrentDirectory);
        unsafe
        {
            int count = 128;

            // 申请内存
            var sz = Marshal.SizeOf(typeof(ST));
            IntPtr ptr = IntPtr.Zero;
            ptr = Marshal.AllocHGlobal(count * sz);

            // 指针转类型
            Test((ST*)ptr, count);
            for (int i = 0; i < count; ++i)
            {
                var data = *((ST*)ptr + i);
                Console.WriteLine("{0}, {1}, {2}", data.a, data.b, data.c);
            }

            // 释放内存(必须要释放!)
            Marshal.FreeHGlobal(ptr);
        }

    }
}