RealMainPage.xaml

<Page
    x:Class="Invaders.RealMainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Invaders"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
    KeyDown="Page_KeyDown">
    <Page.TopAppBar>
        <CommandBar/>
    </Page.TopAppBar>

    <Grid KeyDown="Page_KeyDown">
        <Canvas KeyDown="Page_KeyDown" Name="PlayArea" Margin="180,0,0,0"/>
        <Button Click="Button_Click"  Content="hiButton" Margin="10,450,0,0" VerticalAlignment="Top" Height="390"/>

    </Grid>
    <Page.BottomAppBar>
        <AppBar>

            <StackPanel Orientation="Horizontal">
                <AppBarButton Icon="Add" Content="find symbol"/>
                <TextBlock>Life</TextBlock>
                <ProgressBar Name="life"/>
            </StackPanel>
        </AppBar>

    </Page.BottomAppBar>
</Page>