ComboBox前台xaml绑定数据

<Window.Resources>
        <x:ArrayExtension x:Key="test" Type="sys:String">
            <sys:String>a1</sys:String>
            <sys:String>a2</sys:String>
            <sys:String>a3</sys:String>
        </x:ArrayExtension>
    </Window.Resources>
    <Grid>
        <ComboBox Height="23" HorizontalAlignment="Left" Margin="10,10,0,0" Name="comboBox1" VerticalAlignment="Top" Width="120" 
                  ItemsSource="{StaticResource test}"/>
    </Grid>