前台代码XAML

<Window x:Class="WpfApplication4.Window1"

    xmlns="

    xmlns:x="

    Title="Window1" Height="300" Width="300" WindowState="Normal" WindowStartupLocation="CenterScreen">

    <StackPanel Margin="5">

        <Slider Name="sliderFontSize" Margin="3" Minimum="1" Maximum="40" Value="10" TickFrequency="1"

                IsSnapToTickEnabled="True" TickPlacement="TopLeft">

        </Slider>

        <TextBlock Margin="10" Name="lbSimpleText" Text="Simple text"

                   FontSize="{Binding ElementName=sliderFontSize,Path=Value,Mode=TwoWay}"></TextBlock>

        <StackPanel Orientation="Horizontal">

            <Button Margin="5" Padding="3" Click="cmd_SetSmall">Set to small</Button>

            <Button Margin="5" Padding="3" Click="cmd_SetNormal">Set to Noarmal</Button>

            <Button Margin="5" Padding="3" Click="cmd_SetBig">Set to Big</Button>

        </StackPanel>

        <StackPanel  Orientation="Horizontal" Margin="5" >

            <TextBlock VerticalAlignment="Center" xml:space="preserve">Exact size: </TextBlock>

            <TextBox Text="{Binding ElementName=lbSimpleText,Path=FontSize,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}" Width="100"></TextBox>

        </StackPanel>

            </StackPanel>

</Window>

后台代码 C#

private void cmd_SetSmall(object sender, RoutedEventArgs e)

{

    sliderFontSize.Value = 2;

}

private void cmd_SetNormal(object sender, RoutedEventArgs e)

{

    sliderFontSize.Value = this.FontSize;

}

private void cmd_SetBig(object sender, RoutedEventArgs e)

{

    sliderFontSize.Value = 30;

}