iOS Adding Tab Bar Item on button click

Hi, I was wondering if its possible to add a tab bar item when a button is clicked. I have a tab bar item created already and i want to create new instances of it and display them in the tab bar.

I tried following this example.. http://docs.xamarin.com/recipes/ios/content_controls/tab_bar/create_a_tab_bar

And so far what I did was create a new tab bar controller in the ios designer. And linked it to the CourseEvalViewController (the uiview controller that I want to crate new instances of).

I then created a new class for the UITabBarController..

public partial class TabBarTroll : UITabBarController
{
    private UIViewController[] tabs = new UIViewController[50];
    public TabBarTroll (IntPtr handle) : base (handle)
    {
    }
    public TabBarTroll()
    {
    }

int inc = 0;
    public void AddTab()
    {
        for(int i=0;i<tabs.Length; i++)
        {
            tabs [i] = 
                new CourseEvalViewController {
                Title = "Course " + ++inc,
                TabBarItem = new UITabBarItem (UITabBarSystemItem.History,0)
                    {
                        Image = UIImage.FromFile ("Assets/idcard.png")
                    }
                };
        }
        ViewControllers = tabs;
    }
}

I then call it from the CourseEvalViewController.cs..

TabBarTroll tbt = new TabBarTroll();
partial void AddBtn_TouchUpInside (UIButton sender)
{
    tbt.AddTab();
}

But When I press the Add Button, it doesnt do anything.