An Blank screen Xna App

BasicExample.fs

namespace BasicExample
open Microsoft.Xna.Framework  
    type Basic() as x = 
        inherit Game()
        let graphics = new GraphicsDeviceManager(x)
        override x.Draw (gameTime) = x.GraphicsDevice.Clear(Color.CornflowerBlue)

Osx.Entry.fs

namespace Basic
open MonoMac.AppKit
open MonoMac.Foundation

type AppDelegate() = 
    inherit NSApplicationDelegate()
    override x.FinishedLaunching(notification) = let game = new Basic() in game.Run()
    override x.ApplicationShouldTerminateAfterLastWindowClosed(sender) = true
 
module main =         
    [<EntryPoint>]
    let main args =
        NSApplication.Init ()
        using (new NSAutoreleasePool()) (fun n -> NSApplication.SharedApplication.Delegate <- new AppDelegate()
                                                  NSApplication.Main(args))
        0