Stop a storyboard from executing - xaml

Question

I have a style trigger that causes my stackpanel to fade in and out with mouseover. I would like to add a checkbox to my stackpanel that will cause it to stay open when checked. How can I stop a storyboard in XAML when my checkbox is checked?
<StackPanel Width="25" Opacity="0" Margin="0,0,0,5" HorizontalAlignment="Stretch"
DockPanel.Dock="Right" Background="#FFEEEEEE">
<StackPanel.Style>
<Style>
<Style.Triggers>
<Trigger Property="Control.IsMouseOver" Value="True">
<Trigger.EnterActions>
<StopStoryboard BeginStoryboardName="CloseStoryBoard" />
<BeginStoryboard Name="OpenStoryBoard">
<Storyboard DecelerationRatio="0.8">
<DoubleAnimation
Storyboard.TargetProperty="(FrameworkElement.Width)" To="600" />
<DoubleAnimation Storyboard.TargetProperty="Opacity"
To=".95" />
</Storyboard>
</BeginStoryboard>
</Trigger.EnterActions>
<Trigger.ExitActions>
<StopStoryboard BeginStoryboardName="OpenStoryBoard" />
<BeginStoryboard Name="CloseStoryBoard">
<Storyboard DecelerationRatio="0.8">
<DoubleAnimation
Storyboard.TargetProperty="(FrameworkElement.Width)" To="25.0" />
<DoubleAnimation Storyboard.TargetProperty="Opacity"
To="0.0" />
</Storyboard>
</BeginStoryboard>
</Trigger.ExitActions>
</Trigger>
</Style.Triggers>
</Style>
</StackPanel.Style>
<CheckBox Content"Keep Open" />
</StackPanel>

Answer 1

You can use ControlTemplate instead of StackPanel.Style. But ControlTemplate must declared in Window.Resources. I make this code for you. I hope it works that way which is the you wish.
<Window.Resources>
<ControlTemplate x:Key="myResource" TargetType="ContentControl">
<StackPanel Name="myStackPanel" Width="25" Background="Black" Opacity="0">
<CheckBox Name="myCheckBox" HorizontalAlignment="Center" Content="Keep Open" Foreground="Aqua"/>
</StackPanel>
<ControlTemplate.Triggers>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition SourceName="myStackPanel" Property="IsMouseOver" Value="True"/>
<Condition SourceName="myCheckBox" Property="IsChecked" Value="False"/>
</MultiTrigger.Conditions>
<MultiTrigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="myStackPanel" Storyboard.TargetProperty="(StackPanel.Width)" To="600" Duration="0:0:1" />
<DoubleAnimation Storyboard.TargetName="myStackPanel" Storyboard.TargetProperty="(StackPanel.Opacity)" To="1" />
</Storyboard>
</BeginStoryboard>
</MultiTrigger.EnterActions>
<MultiTrigger.ExitActions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="myStackPanel" Storyboard.TargetProperty="(StackPanel.Width)" To="25" Duration="0:0:1" />
<DoubleAnimation Storyboard.TargetName="myStackPanel" Storyboard.TargetProperty="(StackPanel.Opacity)" To="0.0" />
</Storyboard>
</BeginStoryboard>
</MultiTrigger.ExitActions>
</MultiTrigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition SourceName="myCheckBox" Property="IsChecked" Value="True"/>
</MultiTrigger.Conditions>
<MultiTrigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="myStackPanel" Storyboard.TargetProperty="(StackPanel.Width)" To="600" Duration="0:0:1" />
<DoubleAnimation Storyboard.TargetName="myStackPanel" Storyboard.TargetProperty="(StackPanel.Opacity)" To="1" />
</Storyboard>
</BeginStoryboard>
</MultiTrigger.EnterActions>
<MultiTrigger.ExitActions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="myStackPanel" Storyboard.TargetProperty="(StackPanel.Width)" To="25" Duration="0:0:1" />
<DoubleAnimation Storyboard.TargetName="myStackPanel" Storyboard.TargetProperty="(StackPanel.Opacity)" To="0.01" />
</Storyboard>
</BeginStoryboard>
</MultiTrigger.ExitActions>
</MultiTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Window.Resources>
<ContentControl Template="{StaticResource myResource}"/>

Answer 2

Although I am answering this, credit goes to Zafar above in getting me started. There was one more condition that needed to be added to his suggestion to get exactly the solution I was looking for. I wanted to post the complete solution in case anyone needs this functionality. Below is a StackPanel that fades in and out with the mouseover/out action. It stays open if the checkbox is checked, regardless of mouse position. And goes back to using the mouse over/out once the checkbox is unchecked. I put opacity at 1 for testing, but be sure to set your opacity as needed.
<UserControl.Resources>
<ControlTemplate x:Key="SlideoutResource" TargetType="ContentControl">
<DockPanel HorizontalAlignment="Stretch">
<StackPanel Name="SlideoutStackPanel" Width="25" Opacity="1" Margin="0,0,0,5" HorizontalAlignment="Stretch" DockPanel.Dock="Right" Background="#FFEEEEEE">
<CheckBox Name="KeepOpenCheckBox" Content="Keep Open" />
</StackPanel>
<Rectangle Name="DummyPlaceHolder" /> <!-- This placeholder is needed to make the fade work. -->
</DockPanel>
<ControlTemplate.Triggers>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition x:Name="MouseOverCondition" SourceName="SlideoutStackPanel" Property="IsMouseOver" Value="True"/>
<Condition SourceName="KeepOpenCheckBox" Property="IsChecked" Value="False"/>
</MultiTrigger.Conditions>
<MultiTrigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="SlideoutStackPanel" Storyboard.TargetProperty="(StackPanel.Width)" To="600" Duration="0:0:1" />
<DoubleAnimation Storyboard.TargetName="SlideoutStackPanel" Storyboard.TargetProperty="(StackPanel.Opacity)" To="1" />
</Storyboard>
</BeginStoryboard>
</MultiTrigger.EnterActions>
</MultiTrigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition SourceName="KeepOpenCheckBox" Property="IsChecked" Value="True"/>
</MultiTrigger.Conditions>
<MultiTrigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="SlideoutStackPanel" Storyboard.TargetProperty="(StackPanel.Width)" To="600" Duration="0:0:1" />
<DoubleAnimation Storyboard.TargetName="SlideoutStackPanel" Storyboard.TargetProperty="(StackPanel.Opacity)" To="1" />
</Storyboard>
</BeginStoryboard>
</MultiTrigger.EnterActions>
</MultiTrigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition x:Name="MouseOutCondition" SourceName="SlideoutStackPanel" Property="IsMouseOver" Value="False"/>
<Condition SourceName="KeepOpenCheckBox" Property="IsChecked" Value="False"/>
</MultiTrigger.Conditions>
<MultiTrigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="SlideoutStackPanel" Storyboard.TargetProperty="(StackPanel.Width)" To="25" Duration="0:0:1" />
<DoubleAnimation Storyboard.TargetName="SlideoutStackPanel" Storyboard.TargetProperty="(StackPanel.Opacity)" To="1" />
</Storyboard>
</BeginStoryboard>
</MultiTrigger.EnterActions>
<MultiTrigger.ExitActions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="SlideoutStackPanel" Storyboard.TargetProperty="(StackPanel.Width)" To="600" Duration="0:0:1" />
<DoubleAnimation Storyboard.TargetName="SlideoutStackPanel" Storyboard.TargetProperty="(StackPanel.Opacity)" To="1" />
</Storyboard>
</BeginStoryboard>
</MultiTrigger.ExitActions>
</MultiTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</UserControl.Resources>
<ContentControl Template="{StaticResource SlideoutResource}"/>