ToogleMenuFlyout and MenuFlyoutPresenterStyle Set

I need the items in a ToogleMenuFlyout occupy the full width of the screen. But I'm not solve the problem.

I'm trying to put the width of my Grid (Grid Main page) but I do not get to do in code-behind.

I am applying a style to MenuFlyoutPresenterStyle but also not to give.

my code is:

AppBarButton x:Name="FiltersPhone" Icon="Filter" Label="Names">
                <AppBarButton.Flyout>
                     <MenuFlyout>
                    <MenuFlyout.MenuFlyoutPresenterStyle>
                        <Style TargetType="MenuFlyoutPresenter">
                            <Setter Property="Background" Value="Transparent"/>
                            <Setter Property="BorderThickness" Value="0"/>
                            <Setter Property="Margin" Value="0,4,0,0"/>
                        </Style>
                    </MenuFlyout.MenuFlyoutPresenterStyle>
                    <ToggleMenuFlyoutItem x:Name="FlyoutItemDate" Text="Today" Tag="Date"
                                           IsChecked="True/>

                </MenuFlyout>
                </AppBarButton.Flyout>
            </AppBarButton>

Apply the following should help [Updated to support landscape]:

Note that: this is still not a perfect solution to meet all your requirement. I am just trying to let you understand the MenuFlyoutPresenter's Maxwidth and the ToggleMenuFlyoutItem's width properties are the key to impelement what you want.

Set x:Name = "rootGrid" to page's root grid

In code-behind, implement the following:

public Page2()
{
    this.InitializeComponent();
    this.Loaded += Page2_Loaded;
}

private void Page2_Loaded(object sender, RoutedEventArgs e)
{
    FlyoutItemDate.Width = rootGrid.ActualWidth;
    DisplayInformation di = DisplayInformation.GetForCurrentView();
    di.OrientationChanged += Di_OrientationChanged;
}

private void Di_OrientationChanged(DisplayInformation sender, object args)
{
    if (sender.CurrentOrientation == DisplayOrientations.Portrait)
    {
        FlyoutItemDate.Width = rootGrid.ActualWidth;
    }
    else if(sender.CurrentOrientation == DisplayOrientations.Landscape)
    {
        FlyoutItemDate.Width = rootGrid.ActualHeight;
    }
}

Increase maxwidth of MenuFlyoutPresenter to larger one(like 1000)

 <Style TargetType="MenuFlyoutPresenter">
      <Setter Property="Background" Value="Red"/>
      <Setter Property="BorderThickness" Value="0"/>
      <Setter Property="Margin" Value="0,4,0,0"/>
      <Setter Property="MaxWidth" Value="1000"/>
 </Style>

Here is the result and I make the background to red to make it clear: