Question

如何在代码后面的ListBox上禁用VisualState动画？我已经为ListBoxItem创建了Selected和Unselected VisualState故事板动画，但是当我的ListBox ItemsSource更改ListBox时，将执行Selected和Unselected动画（我认为所有项目都会自动被选中和取消选择一秒钟）。

编辑：找到变通方法解决方案 - 如果您在项目源更改时获得选定和未选定动画，则可以使用它。看起来这样的自动选择更改甚至不会引发SelectionChanged事件。

public class ListBoxSelectedFoldersAnimationBehaviour : Behavior<ListBox>
{
    protected override void OnAttached()
    {
        base.OnAttached();
        AssociatedObject.SelectionChanged += ListBoxOnSelectionChanged;
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();
        AssociatedObject.SelectionChanged -= ListBoxOnSelectionChanged;
    }

    private void ListBoxOnSelectionChanged(object sender, SelectionChangedEventArgs selectionChangedEventArgs)
    {
        foreach (var item in selectionChangedEventArgs.AddedItems)
        {
            var listBoxItem = AssociatedObject.ItemContainerGenerator.ContainerFromItem(item) as ListBoxItem;
            if (listBoxItem != null)
                SetItemSelectedAnimation(listBoxItem);
        }

        foreach (var item in selectionChangedEventArgs.RemovedItems)
        {
            var listBoxItem = AssociatedObject.ItemContainerGenerator.ContainerFromItem(item) as ListBoxItem;
            if (listBoxItem != null) // listboxitem can be null after removing item from ListBox.ItemsSource
                SetItemUnselectedAnimation(listBoxItem);
        }
    }

    private void SetItemSelectedAnimation(ListBoxItem item)
    { // sample opacity animation
        var storyboard = new Storyboard();
        var fadeOutAnimation = new DoubleAnimation()
        {
            EasingFunction = new CubicEase() { EasingMode = EasingMode.EaseOut },
            Duration = new Duration(TimeSpan.FromMilliseconds(200)),
            From = 1.0,
            To = 0.6
        };
        storyboard.Children.Add(fadeOutAnimation);
        Storyboard.SetTarget(storyboard, item);
        Storyboard.SetTargetProperty(storyboard, new PropertyPath(ListBoxItem.OpacityProperty));
        storyboard.Begin();
    }

    private void SetItemUnselectedAnimation(ListBoxItem item)
    { // sample opacity animation
        var storyboard = new Storyboard();
        var fadeInAnimation = new DoubleAnimation()
        {
            EasingFunction = new CubicEase() { EasingMode = EasingMode.EaseIn },
            Duration = new Duration(TimeSpan.FromMilliseconds(200)),
            From = 0.6,
            To = 1.0
        };
        storyboard.Children.Add(fadeInAnimation);
        Storyboard.SetTarget(storyboard, item);
        Storyboard.SetTargetProperty(storyboard, new PropertyPath(ListBoxItem.OpacityProperty));
        storyboard.Begin();
    }
}


xaml:
<Page xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
      xmlns:classNamespace="clr-namespace:YourProjectName.NamespaceOfBehaviourClass">
...

<ListBox>
    <i:Interaction.Behaviors>
        <classNamespace:ListBoxSelectedFoldersAnimationBehaviour/>
    </i:Interaction.Behaviors>
</ListBox>

我还没检查它是否泄漏内存（因为我没有停止故事板）所以记住这一点。

在后面的代码中禁用VisualStates - WP8

0 个答案: