How can I change the font size of a label in my ControlTemplate

In my WPF ListBox, I have a style with a ControlTemplate for a ListBoxItem. Inside that ControlTemplate I have a label defined. Based on some details, I need to change the font size of the label. So from my code-behind, I need to determine what the font should be and then set it.

Here is my style with the ControlTemplate (I've stripped out some irrelevant controls)

<Style x:Key="RecordTabList" TargetType="{x:Type ListBoxItem}">
            <Setter Property="Background" Value="{DynamicResource RecordIndexTabBackcolor}" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate>        
                            <Label x:Name="myLabel" Grid.Column="0" Grid.ColumnSpan="1" Grid.Row="0" Grid.RowSpan="1" Margin="3,-2,0,-2" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" FontSize="10" Height="Auto" BorderThickness="3,0,0,0" Content="{Binding Path=Name}" Foreground="{DynamicResource RecordIndexTabForeground}" />
                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>

How can I do this?

From stackoverflow

• You might be able to use a ValueConverter on the FontSize property.. but I'm not 100% sure if they work inside a ControlTemplate.. I seem to remember Silverlight having issues with it, but I can't remember if it worked in WPF.

• If I understand you correctly, you can probably do something similar to the following, and simply change the FontSize property on the ListBoxItem itself; it will be reflected automatically on your Label. Copy this into VS and see it in action!

  <Window.Resources>
      <Style TargetType="ListBoxItem">
          <Setter Property="Template">
              <Setter.Value>
                  <ControlTemplate TargetType="ListBoxItem">
                      <Label Content="{TemplateBinding Content}" FontSize="{TemplateBinding FontSize}"/>
                  </ControlTemplate>
              </Setter.Value>
          </Setter>
      </Style>
  </Window.Resources>
  <Grid>
      <ListBox Margin="12">
          <ListBoxItem Content="Test 1" FontSize="14"/>
          <ListBoxItem Content="Test 2" FontSize="18"/>
          <ListBoxItem Content="Test 3" FontSize="22"/>
      </ListBox>
  </Grid>
  

• If you want to set the FontSize in the code behind, you should remove FontSize from the ControlTemplate, then set it for the ListBoxItem in the code-behind. If you want to set the same size for all the ListBoxItems just set the FontSize of the ListBox in the code-behind.