C#调用非托管代码：没法封送处理“return value”: 无效的托管/非托管类型组合

extern "C" __declspec(dllexport) int* TestSetArray(IN int arr[1024])
{
    for(int i=0;i < 99; i++)
    {
        arr[i] = i;
    }

    return arr;
}code]

C#调用：
[code=C#][DllImport("TestDLL.dll", EntryPoint = "Add", ExactSpelling = false, CallingConvention = CallingConvention.Cdecl)]
        public static extern int Add(int a, int b);

[DllImport("TestDLL.dll",
            EntryPoint = "TestSetArray",
            ExactSpelling = true,
            CallingConvention = CallingConvention.Cdecl,
            CharSet = CharSet.Ansi)]
        public static extern int[] TestSetArray([MarshalAs(UnmanagedType.LPArray)] int[] arr);

static unsafe void Main(string[] args)
        {
            Console.WriteLine(Add(1,2));
            Console.WriteLine();

            int[] arr = new int[1024];           
            int[] arr1 = TestSetArray(arr);

            Console.WriteLine();
            Console.Read();
            
        }