managed pinvoke signature does not match

I write a simple c++ dll & when i am call it in 3.5 frame work it works fine.
The call is like that.....

[DllImport("MyDll.dll")]
        public static extern int add(int a, int b);

        private void button1_Click(object sender, EventArgs e)
        {
            int x = 5, y = 9;
            int z = add(x, y);
            MessageBox.Show(Convert.ToString(z));
        }
it works fine no doubt. (return 14)

But when I put this code in framework 4 it gets an error.
the error is ->

"..... the managed pinvoke signature does not match the unmanaged target signature ....."

Please help me, what i do to overcome this problem in Framework 4.

Thank you in advance!

I got the solution,

[DllImport("MyDll.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern int add(int a,int b);

this is work in framework 4.
And now there is no exception. It well work now.

Thank you!

Hi Tanmay Sarkar,

Thank you very much for your own answer to your problem :D. I have the same problem as yours, and it has driven me crazy for a whole day.

I register an account at this forum just to say thank you :)

Best regards,

Kakashi

Thanks Kakashi,

that problem can really make any body to crazy, while it well work in framework 3.5 but not work in 4.

Welcome to this forum, enjoy it.

Thank You! :)