wpf - 如何在另一个 xaml 的控件上应用双动画？

Question

我有一个按钮，应该会导致位于另一个 xaml 中的其他一些控件(Studio、Animation、Record...)上出现淡入动画:

<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>

如何在我当前的 xaml 中引用这些控件？只是提一下，我使用 mvvm，并且我不想引用 ViewModel 类中的按钮控件。

Answer 1

在 ViewModel 中创建一个事件，并将事件触发器附加到 XAML(例如 ControlStoryboardAction)，该触发器在事件触发后立即启动动画。

编辑:

你可以在你的虚拟机中放置类似的东西:

public event EventHandler AnimationCalled;

protected virtual void OnAnimationCalled()
{
    AnimationCalled?.Invoke(this, EventArgs.Empty);
}

只要有任何东西调用 OnAnimationCalled(由按钮或命令触发的任何方法)，就会引发事件。

您可以使用触发器(SourceObject 必须是包含您的事件的 VM)结合 ControlStoryboardAction 在 XAML 中订阅此事件:

<i:Interaction.Triggers>
    <i:EventTrigger SourceObject="{Binding Mode=OneWay}" EventName="AnimationCalled">
        <ei:ControlStoryboardAction Storyboard="{StaticResource Storyboard1}"/>
    </i:EventTrigger>
</i:Interaction.Triggers>

---

编辑 2:完整示例 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);
        }
    }
}

将包含我们的 Storyboard 的UserControl:

<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>

还有我们的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>

应该看起来像这样:

应该通过 Storyboard将动画移动到此，通过单击按钮:

您可以在 GitHub 下载解决方案