[DllImport("dll名字.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.Cdecl)]
unsafe public static extern byte* ShowImages(byte[] src, int w, int h);
可以参考:
http://www.cnblogs.com/mqxs/p/3293203.html
和类一样,实例化 new ,A a = new A(); a.xxx();这样