MainPage.xaml

<UserControl x:Class="ViewBoxSnippet.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <!--<snippetViewBoxXAML>-->
    <Grid Height="600" Width="600">
        <Grid.ColumnDefinitions>
            <ColumnDefinition />
            <ColumnDefinition />
        </Grid.ColumnDefinitions>
        
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="auto" />
            <RowDefinition />
        </Grid.RowDefinitions>
        
        <StackPanel Grid.Row="0" Grid.Column="0" Margin="5,5,5,5" Orientation="Vertical">
            <TextBlock Text="Stretch" FontWeight="Bold" FontSize="12" />
            <Button Name="btn1" Click="stretchNone" Content="None" />
            <Button Name="btn2" Click="stretchFill" Content="Fill" />
            <Button Name="btn3" Click="stretchUni" Content="Uniform" />
            <Button Name="btn4" Click="stretchUniFill" Content="UniformToFill" />
        </StackPanel>

        <StackPanel Grid.Row="0" Grid.Column="1" Margin="5,5,5,5" Orientation="Vertical">
            <TextBlock Text="StretchDirection" FontWeight="Bold" FontSize="12" />
            <Button Name="btn5" Click="sdUpOnly" Content="UpOnly" />
            <Button Name="btn6" Click="sdDownOnly" Content="DownOnly" />
            <Button Name="btn7" Click="sdBoth" Content="Both" />
        </StackPanel>

        <StackPanel Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2" Margin="5" 
                    Orientation="Vertical">
            <TextBlock Name="txt1" FontSize="12" FontWeight="Bold" />
            <TextBlock Name="txt2" FontSize="12" FontWeight="Bold" />
        </StackPanel>   

        <StackPanel Grid.Row="2" Grid.Column="0" Grid.ColumnSpan="2" Margin="5" 
                    Orientation="Horizontal">
            <Viewbox MaxWidth="100" MaxHeight="100" Name="vb1">
                <Image Source="flower.jpg"/>
            </Viewbox>
            <Viewbox MaxWidth="200" MaxHeight="200" Name="vb2">
                <Image Source="flower.jpg"/>
            </Viewbox>
            
            <Viewbox MaxWidth="300" MaxHeight="300" Name="vb3">
                <Image Source="flower.jpg"/>
            </Viewbox>
        </StackPanel>

    </Grid>
    <!--</snippetViewBoxXAML>-->
</UserControl>