Question

in the following example, I don’t understand how I could make my “Live Updates” groupbox appear/disappear when the upper checkbox is checked/unchecked. I am looking for a fast fade in/fade out effect in XAML but I am a little lost..

<UserControl
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    x:Class="WpfControlLibrary1.MainControl"
    x:Name="MultiVol" MinHeight="520.12" MinWidth="213">

    <Grid HorizontalAlignment="Stretch">
        <Grid.Background>
                <LinearGradientBrush EndPoint="0.5,1" MappingMode="RelativeToBoundingBox" StartPoint="0.5,0">
                    <GradientStop Color="White" Offset="0.966"/>
                    <GradientStop Color="#FFD7D4FF"/>
                </LinearGradientBrush>
        </Grid.Background>

        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition />
        </Grid.ColumnDefinitions>

        <StackPanel x:Name="LayoutRoot" HorizontalAlignment="Stretch"  Grid.Row="0">

            <GroupBox Margin="8,0" BorderBrush="#FF88B1D8" HorizontalAlignment="Stretch" Height="99">
                <GroupBox.Header>
                    <WrapPanel>
                    <Label Content="General" Background="#00000000" Foreground="#FF0033FF" FontWeight="Bold" FontFamily="/WpfControlLibrary1;component/Fonts/#Tahoma" />    
                    </WrapPanel>
                </GroupBox.Header>

                <UniformGrid Columns="2">
                    <Label Content="RICs" />
                    <TextBox AcceptsReturn="False" AcceptsTab="True" AllowDrop="True" IsTabStop="True" />
                    <Label Content="Preference" />
                    <UniformGrid VerticalAlignment="Center" Columns="2" Rows="1">
                        <RadioButton GroupName="preference" Content="Exotic" IsChecked="False" />
                        <RadioButton GroupName="preference" Content="Flow" IsChecked="True" />
                    </UniformGrid>
                    <Label Content="Live updates" />
                    <CheckBox IsChecked="True" VerticalAlignment="Center"/>
                </UniformGrid>  
            </GroupBox>
        </StackPanel>

        <DockPanel Grid.Row="1" HorizontalAlignment="Stretch">
            <GroupBox Margin="8,0" BorderBrush="#FF88B1D8" HorizontalAlignment="Stretch">
                <GroupBox.Header>
                    <WrapPanel>
                    <Label Content="Live updates" Background="#00000000" Foreground="#FF0033FF" FontWeight="Bold" FontFamily="/WpfControlLibrary1;component/Fonts/#Tahoma" />   
                    </WrapPanel>
                </GroupBox.Header>
                    <ListView MinHeight="100" Background="{x:Null}">
                        <ListView.View>
                            <GridView AllowsColumnReorder="False">
                                <GridViewColumn Header="RIC" />
                                <GridViewColumn Header="Last tick" />
                           </GridView>
                        </ListView.View>
                    </ListView>
            </GroupBox>         
        </DockPanel>

        </Grid>
</UserControl>

UPDATE : I get the fade in now, and I tried to add the fade out by adding a Trigger tag :

           <DockPanel.Style>
                <Style TargetType="{x:Type DockPanel}">
                    <Style.Triggers>
                        <Trigger Property="Visibility" Value="Visible">
                            <Trigger.EnterActions>
                                <BeginStoryboard>
                                    <Storyboard>
                                        <DoubleAnimation Storyboard.TargetProperty="Opacity" Duration="00:00:0.5" From="0.0" To="1.0" />
                                    </Storyboard>
                                </BeginStoryboard>
                            </Trigger.EnterActions>
                        </Trigger>
                        <Trigger Property="Visibility" Value="Hidden">
                            <Trigger.EnterActions>
                                <BeginStoryboard>
                                    <Storyboard>
                                        <DoubleAnimation Storyboard.TargetProperty="Opacity" Duration="00:00:0.5" From="1.0" To="0.0" />
                                    </Storyboard>
                                </BeginStoryboard>
                            </Trigger.EnterActions>
                        </Trigger>
                    </Style.Triggers>
                </Style>
            </DockPanel.Style>

Answer 1

Two steps.
First Visibility:

• Create a BooleanToVisibilityConverter in Resources

  <UserControl.Resources>
      <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter" />
  </UserControl.Resources>
  

• Give your CheckBox a name

  <CheckBox x:Name="LiveUpdateCheckBox" IsChecked="True" VerticalAlignment="Center" />
  

• Bind the DockPanel.Visibility property per ElementName with BooleanToVisibilityConverter

  <DockPanel Grid.Row="1" HorizontalAlignment="Stretch"
             Visibility="{Binding ElementName=LiveUpdateCheckBox, Path=IsChecked, Converter={StaticResource BooleanToVisibilityConverter}}">
  

Second Animation:

• Create a DockPanel.Style for your LiveUpdates DockPanel

  <DockPanel.Style>
      <Style TargetType="{x:Type DockPanel}">
          <Style.Triggers>
              <Trigger Property="Visibility" Value="Visible">
                  <Trigger.EnterActions>
                      <BeginStoryboard>
                          <Storyboard>
                              <DoubleAnimation Storyboard.TargetProperty="Opacity" Duration="00:00:01" From="0.0" To="1.0" />
                          </Storyboard>
                      </BeginStoryboard>
                  </Trigger.EnterActions>
              </Trigger>
          </Style.Triggers>
      </Style>
  </DockPanel.Style>