Its 5:20 AM and I woke up at 4:45 with an approach that would make my life easier. Had to code it. It worked beautifully, so I had to blog it to get opinions and help others.
The app I am working on have 2 states, and on each state the user will see a different set of buttons and menu items on the app bar.
I didnt want to write the app bar completely in C#, for I always choose XAML over C# when possible. Otherwise we would just write it all in C#!
I started by creating the buttons as app resources in APP.XAML. Note that some buttons overlap both app bars, so this approach avoids having 2 buttons that do the same thing.
<shell:ApplicationBarIconButton x:Key="ChooseButton" IconUri="/Images/ChooseButton.png" Text="choose">
I then added both app bars to APP.XAML resource as well, referencing the buttons as StaticResources
<shell:ApplicationBar x:Key="AppBarState1" IsVisible="True" Opacity="0.5">
<StaticResource ResourceKey="ChooseButton" />
Now on the page code behind comes the inevitable C#. I feel this is perfectly OK as it has to do with procedure and intelligence rather then declaration.
var chooseButton = (ApplicationBarIconButton)App.Current.Resources["ChooseButton"];
chooseButton.Click += ChooseButtonClick;
After setting up the button handlers we will decide which app bar to show and assign it to the page's ApplicationBar property:
ApplicationBar = (IApplicationBar)App.Current.Resources["AppBarState1"]; // choose based on app state
I hope this helps some folks. If you think of a more elegant or appropriate way of achieving the same , please let us know.