When you want your app to expand to the full screen (including status bar and appbar), you have to do :
var applicationView = Windows.UI.ViewManagement.ApplicationView.GetForCurrentView();
applicationView.SetDesiredBoundsMode(Windows.UI.ViewManagement.ApplicationViewBoundsMode.UseCoreWindow);
Then if you want to have a flyout in your appbar or anywhere in your app, they will be displayed behind the appbar :
<Page.BottomAppBar>
<CommandBar>
<AppBarButton Icon="Preview" Label="Preview">
<AppBarButton.Flyout>
<MenuFlyout>
<MenuFlyoutItem Text="Fit width" />
<MenuFlyoutItem Text="Fit height" />
<MenuFlyoutItem Text="Fit page" />
</MenuFlyout>
</AppBarButton.Flyout>
</AppBarButton>
</CommandBar>
</Page.BottomAppBar>
The result :
Same thing with flyouts on an item in a listview. They will be displayed behind the appbar :
How can i display the flyouts on top of the appbar ?
I can't seem to solve my issue (or someone who can help). So i did it that way, if it can help someone :
Now my flyout appears fully, since there is no more appbar. For mvvm list view items, i did it in a behavior action :