Is .NET PInvoke available on Linux and Mac OS X platforms?

Platform Invokation in .NET Framework available on Windows.

[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern MessageBoxResult MessageBox(IntPtr hWnd, String text, String caption, int options);

Is PInvoke avail开发者_运维技巧able on Linux and Mac OS X platforms? for example for Mono project?

If Linux and Mac OS X supported PInvoke, Can you give me some example or references in your answer.

Thanks.

Interop with Native Libraries
http://www.mono-project.com/Interop_with_Native_Libraries