How to apply double animation on a control from another xaml? - wpf

Question

I have a button that should cause fade-in animation on some other controls(Studio, Animation, Record...) which are located in ANOTHER xaml:
<Button x:Name ="MainButton" Grid.Row="87" Grid.Column="150" Grid.ColumnSpan="2" Grid.RowSpan="2" Command="{Binding AutoClickFadeinButtonCommand}">
<Button.Triggers>
<EventTrigger RoutedEvent="PreviewMouseDown">
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="Studio" Storyboard.TargetProperty="Opacity" From="0" To="1" Duration="0:0:2"/>
<DoubleAnimation Storyboard.TargetName="Animation" Storyboard.TargetProperty="Opacity" From="0" To="0.3" Duration="0:0:2"/>
<DoubleAnimation Storyboard.TargetName="Record" Storyboard.TargetProperty="Opacity" From="0" To="0.3" Duration="0:0:2"/>
<DoubleAnimation Storyboard.TargetName="Info" Storyboard.TargetProperty="Opacity" From="0" To="1" Duration="0:0:2"/>
<DoubleAnimation Storyboard.TargetName="info_content" Storyboard.TargetProperty="Opacity" From="0" To="1" Duration="0:0:2"/>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Button.Triggers>
</Button>
How to reference these controls in my current xaml? Just to mention that I use mvvm, and I would like not to reference button control inside ViewModel class.

Answer 1

Create an event inside your ViewModel and attach an event trigger to your XAML (e.g. ControlStoryboardAction) that starts the animation as soon as the event has been triggered.
Edit:
You could put something like that inside your VM:
public event EventHandler AnimationCalled;
protected virtual void OnAnimationCalled()
{
AnimationCalled?.Invoke(this, EventArgs.Empty);
}
As soon as anything will call OnAnimationCalled (any method that is triggered by your button or a command) the event will be raised.
You can subscribe to this event inside XAML by using a trigger (the SourceObject has to be the VM containing your event) in combination with the ControlStoryboardAction:
<i:Interaction.Triggers>
<i:EventTrigger SourceObject="{Binding Mode=OneWay}" EventName="AnimationCalled">
<ei:ControlStoryboardAction Storyboard="{StaticResource Storyboard1}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
Edit 2: Complete Example
The MainViewModel:
using System;
namespace StoryboardTriggerExample
{
public class MainViewModel
{
//Only needed to have a target for our CallMethodAction
//In real world it´d be easier to make the call to OnAnimationCalled(); via command
public void CallAnimation()
{
OnAnimationCalled();
}
public event EventHandler AnimationCalled;
protected virtual void OnAnimationCalled()
{
AnimationCalled?.Invoke(this, EventArgs.Empty);
}
}
}
An UserControl that will contain our Storyboard:
<UserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:StoryboardTriggerExample"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity" xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions" x:Class="StoryboardTriggerExample.UserControlContainingStoryboard"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<UserControl.Resources>
<Storyboard x:Key="Storyboard1">
<ColorAnimationUsingKeyFrames Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" Storyboard.TargetName="rectangle">
<EasingColorKeyFrame KeyTime="0:0:1" Value="#FF101085"/>
</ColorAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(FrameworkElement.Height)" Storyboard.TargetName="rectangle">
<EasingDoubleKeyFrame KeyTime="0:0:1" Value="30"/>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(FrameworkElement.Width)" Storyboard.TargetName="rectangle">
<EasingDoubleKeyFrame KeyTime="0:0:1" Value="30"/>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(FrameworkElement.Width)" Storyboard.TargetName="rectangle1">
<EasingDoubleKeyFrame KeyTime="0:0:1" Value="100"/>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(FrameworkElement.Height)" Storyboard.TargetName="rectangle1">
<EasingDoubleKeyFrame KeyTime="0:0:1" Value="100"/>
</DoubleAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" Storyboard.TargetName="rectangle1">
<EasingColorKeyFrame KeyTime="0:0:1" Value="#FF6BFF63"/>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</UserControl.Resources>
<StackPanel>
<i:Interaction.Triggers>
<i:EventTrigger EventName="AnimationCalled" SourceObject="{Binding Mode=OneWay}">
<ei:ControlStoryboardAction Storyboard="{StaticResource Storyboard1}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
<Rectangle x:Name="rectangle1" Fill="#FFF4F4F5" Height="30" Stroke="Black" Width="30" HorizontalAlignment="Left" d:LayoutOverrides="LeftPosition, RightPosition, TopPosition, BottomPosition"/>
<Rectangle x:Name="rectangle" Fill="#FFF4F4F5" Height="100" Stroke="Black" Width="100" HorizontalAlignment="Left" VerticalAlignment="Top"/>
</StackPanel>
And our MainWindow:
<Window
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"
xmlns:local="clr-namespace:StoryboardTriggerExample"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity" xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions" x:Class="StoryboardTriggerExample.MainWindow"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<local:MainViewModel/>
</Window.DataContext>
<StackPanel>
<Button x:Name="button" Content="Button">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<ei:CallMethodAction TargetObject="{Binding Mode=OneWay}" MethodName="CallAnimation"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</Button>
<local:UserControlContainingStoryboard/>
</StackPanel>
Should look like this:
Should move animated via storyboard to this, by clicking the button:
You can download the solution on GitHub