Problem with Toolbar added in each tabbed page

Hi,

I am using TabbedPage. I am having two tabs, each will navigate to different pages. In each page i added different toolbar items. But, second tab instead of showing its Toolbar item, its showing first tabpage's Toolbar.

How can i fix this? I want different ToolBar in each tabbed page.

TabbedPageDemoPage .cs:

public class TabbedPageDemoPage : TabbedPage
{
    public TabbedPageDemoPage ()
            {

                this.Children.Add ( new ContactsListViewPage() { Title = "Contacts" } );
                this.Children.Add ( new GroupListViewPage() { Title = "Groups" } );
            }
}

ContactsListViewPage.cs:

public ContactsListViewPage ()
        {
            InitializeComponent ();

            this.ToolbarItems.Add(new ToolbarItem("Add Contact", "icon_plus_30x30.png", async () =>
            {
                Navigation.PushModalAsync(new EditContactPage(null));
            }));


        }

GroupListViewPage.cs:

public GroupListViewPage()
        {
            InitializeComponent ();

            this.ToolbarItems.Add(new ToolbarItem("Add Group", null, async () =>
            {
                    Navigation.PushModalAsync(new EditGroupPage());
            }));

        }