Question

我为Button创建了一个Blend行为。如何将其设置为应用程序中的所有按钮。

<Button ...>
  <i:Interaction.Behaviors>
    <local:MyBehavior />
  </i:Interaction.Behaviors>
</Button>

然而，当我尝试：

<Style>
  <Setter Property="i:Interaction.Behaviors">
    <Setter.Value>
      <local:MyBehavior />
    </Setter.Value>
  </Setter>
</Style>

我收到错误

属性“行为”没有可访问的setter。

Answer 1

我遇到了同样的问题，我想出了一个解决方案。在我解决之后我发现了这个问题，我发现我的解决方案与马克有很多共同之处。但是，这种方法略有不同。

主要问题是行为和触发器与特定对象相关联，因此您不能对多个不同的关联对象使用相同的行为实例。当您定义行为内联时，XAML会强制执行此一对一关系。但是，当您尝试在样式中设置行为时，可以将样式重用于它应用的所有对象，这将在基本行为类中引发异常。事实上，作者付出了相当大的努力来阻止我们甚至试图这样做，因为它知道它不会起作用。

第一个问题是我们甚至无法构造行为设置器值，因为构造函数是内部的。所以我们需要自己的行为并触发集合类。

下一个问题是行为和触发器附加属性没有setter，因此它们只能添加到内联XAML中。我们使用自己的附加属性来解决这个问题，这些属性操纵主要行为和触发属性。

第三个问题是我们的行为集合仅适用于单个样式目标。我们通过使用一个很少使用的XAML功能x:Shared="False"来解决这个问题，每次引用它时都会创建一个新的资源副本。

最后一个问题是行为和触发器不像其他样式设置器;我们不希望用新行为替换旧行为，因为它们可能会做出截然不同的事情。因此，如果我们接受一旦你添加了一个你不能把它带走的行为（这就是行为目前的工作方式），我们可以得出结论，行为和触发器应该是附加的，这可以通过我们附加的属性来处理。

以下是使用此方法的示例：

<Grid>
    <Grid.Resources>
        <sys:String x:Key="stringResource1">stringResource1</sys:String>
        <local:Triggers x:Key="debugTriggers" x:Shared="False">
            <i:EventTrigger EventName="MouseLeftButtonDown">
                <local:DebugAction Message="DataContext: {0}" MessageParameter="{Binding}"/>
                <local:DebugAction Message="ElementName: {0}" MessageParameter="{Binding Text, ElementName=textBlock2}"/>
                <local:DebugAction Message="Mentor: {0}" MessageParameter="{Binding Text, RelativeSource={RelativeSource AncestorType={x:Type FrameworkElement}}}"/>
            </i:EventTrigger>
        </local:Triggers>
        <Style x:Key="debugBehavior" TargetType="FrameworkElement">
            <Setter Property="local:SupplementaryInteraction.Triggers" Value="{StaticResource debugTriggers}"/>
        </Style>
    </Grid.Resources>
    <StackPanel DataContext="{StaticResource stringResource1}">
        <TextBlock Name="textBlock1" Text="textBlock1" Style="{StaticResource debugBehavior}"/>
        <TextBlock Name="textBlock2" Text="textBlock2" Style="{StaticResource debugBehavior}"/>
        <TextBlock Name="textBlock3" Text="textBlock3" Style="{StaticResource debugBehavior}"/>
    </StackPanel>
</Grid>

该示例使用触发器，但行为的工作方式相同。在示例中，我们显示：

该样式可以应用于多个文本块
几种类型的数据绑定都能正常工作
在输出窗口中生成文本的调试操作

这是一个示例行为，我们的DebugAction。更恰当的是，这是一种行为，但通过滥用语言，我们将行为，触发器和行为称为“行为”。

public class DebugAction : TriggerAction<DependencyObject>
{
    public string Message
    {
        get { return (string)GetValue(MessageProperty); }
        set { SetValue(MessageProperty, value); }
    }

    public static readonly DependencyProperty MessageProperty =
        DependencyProperty.Register("Message", typeof(string), typeof(DebugAction), new UIPropertyMetadata(""));

    public object MessageParameter
    {
        get { return (object)GetValue(MessageParameterProperty); }
        set { SetValue(MessageParameterProperty, value); }
    }

    public static readonly DependencyProperty MessageParameterProperty =
        DependencyProperty.Register("MessageParameter", typeof(object), typeof(DebugAction), new UIPropertyMetadata(null));

    protected override void Invoke(object parameter)
    {
        Debug.WriteLine(Message, MessageParameter, AssociatedObject, parameter);
    }
}

最后，我们的集合和附加属性使这一切都有效。与Interaction.Behaviors类比，您定位的属性称为SupplementaryInteraction.Behaviors，因为通过设置此属性，您将向Interaction.Behaviors添加行为，同样为触发器添加行为。

public class Behaviors : List<Behavior>
{
}

public class Triggers : List<TriggerBase>
{
}

public static class SupplementaryInteraction
{
    public static Behaviors GetBehaviors(DependencyObject obj)
    {
        return (Behaviors)obj.GetValue(BehaviorsProperty);
    }

    public static void SetBehaviors(DependencyObject obj, Behaviors value)
    {
        obj.SetValue(BehaviorsProperty, value);
    }

    public static readonly DependencyProperty BehaviorsProperty =
        DependencyProperty.RegisterAttached("Behaviors", typeof(Behaviors), typeof(SupplementaryInteraction), new UIPropertyMetadata(null, OnPropertyBehaviorsChanged));

    private static void OnPropertyBehaviorsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var behaviors = Interaction.GetBehaviors(d);
        foreach (var behavior in e.NewValue as Behaviors) behaviors.Add(behavior);
    }

    public static Triggers GetTriggers(DependencyObject obj)
    {
        return (Triggers)obj.GetValue(TriggersProperty);
    }

    public static void SetTriggers(DependencyObject obj, Triggers value)
    {
        obj.SetValue(TriggersProperty, value);
    }

    public static readonly DependencyProperty TriggersProperty =
        DependencyProperty.RegisterAttached("Triggers", typeof(Triggers), typeof(SupplementaryInteraction), new UIPropertyMetadata(null, OnPropertyTriggersChanged));

    private static void OnPropertyTriggersChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var triggers = Interaction.GetTriggers(d);
        foreach (var trigger in e.NewValue as Triggers) triggers.Add(trigger);
    }
}

并且你有它，通过样式应用的全功能行为和触发器。

Answer 2

总结答案和这篇伟大的文章Blend Behaviors in Styles，我找到了这个通用的简短而方便的解决方案：

我制作了泛型类，可以通过任何行为继承。

public class AttachableForStyleBehavior<TComponent, TBehavior> : Behavior<TComponent>
        where TComponent : System.Windows.DependencyObject
        where TBehavior : AttachableForStyleBehavior<TComponent, TBehavior> , new ()
    {
        public static DependencyProperty IsEnabledForStyleProperty =
            DependencyProperty.RegisterAttached("IsEnabledForStyle", typeof(bool),
            typeof(AttachableForStyleBehavior<TComponent, TBehavior>), new FrameworkPropertyMetadata(false, OnIsEnabledForStyleChanged)); 

        public bool IsEnabledForStyle
        {
            get { return (bool)GetValue(IsEnabledForStyleProperty); }
            set { SetValue(IsEnabledForStyleProperty, value); }
        }

        private static void OnIsEnabledForStyleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            UIElement uie = d as UIElement;

            if (uie != null)
            {
                var behColl = Interaction.GetBehaviors(uie);
                var existingBehavior = behColl.FirstOrDefault(b => b.GetType() ==
                      typeof(TBehavior)) as TBehavior;

                if ((bool)e.NewValue == false && existingBehavior != null)
                {
                    behColl.Remove(existingBehavior);
                }

                else if ((bool)e.NewValue == true && existingBehavior == null)
                {
                    behColl.Add(new TBehavior());
                }    
            }
        }
    }

所以你可以简单地重复使用它，如下所示：

public class ComboBoxBehaviour : AttachableForStyleBehavior<ComboBox, ComboBoxBehaviour>
    { ... }

在XAML中足以声明：

 <Style TargetType="ComboBox">
            <Setter Property="behaviours:ComboBoxBehaviour.IsEnabledForStyle" Value="True"/>

基本上，AttachableForStyleBehavior类创建了xaml，为样式中的每个组件注册行为实例。有关详细信息，请参阅链接。

Answer 3

1.创建附属财产

public static class DataGridCellAttachedProperties
{
    //Register new attached property
    public static readonly DependencyProperty IsSingleClickEditModeProperty =
        DependencyProperty.RegisterAttached("IsSingleClickEditMode", typeof(bool), typeof(DataGridCellAttachedProperties), new UIPropertyMetadata(false, OnPropertyIsSingleClickEditModeChanged));

    private static void OnPropertyIsSingleClickEditModeChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var dataGridCell = d as DataGridCell;
        if (dataGridCell == null)
            return;

        var isSingleEditMode = GetIsSingleClickEditMode(d);
        var behaviors =  Interaction.GetBehaviors(d);
        var singleClickEditBehavior = behaviors.SingleOrDefault(x => x is SingleClickEditDataGridCellBehavior);

        if (singleClickEditBehavior != null && !isSingleEditMode)
            behaviors.Remove(singleClickEditBehavior);
        else if (singleClickEditBehavior == null && isSingleEditMode)
        {
            singleClickEditBehavior = new SingleClickEditDataGridCellBehavior();
            behaviors.Add(singleClickEditBehavior);
        }
    }

    public static bool GetIsSingleClickEditMode(DependencyObject obj)
    {
        return (bool) obj.GetValue(IsSingleClickEditModeProperty);
    }

    public static void SetIsSingleClickEditMode(DependencyObject obj, bool value)
    {
        obj.SetValue(IsSingleClickEditModeProperty, value);
    }
}

2.创建行为

public class SingleClickEditDataGridCellBehavior:Behavior<DataGridCell>
        {
            protected override void OnAttached()
            {
                base.OnAttached();
                AssociatedObject.PreviewMouseLeftButtonDown += DataGridCellPreviewMouseLeftButtonDown;
            }

            protected override void OnDetaching()
            {
                base.OnDetaching();
                AssociatedObject.PreviewMouseLeftButtonDown += DataGridCellPreviewMouseLeftButtonDown;
            }

            void DataGridCellPreviewMouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
            {
                 DataGridCell cell = sender as DataGridCell;
                if (cell != null && !cell.IsEditing && !cell.IsReadOnly)
                {
                    if (!cell.IsFocused)
                    {
                        cell.Focus();
                    }
                    DataGrid dataGrid = LogicalTreeWalker.FindParentOfType<DataGrid>(cell); //FindVisualParent<DataGrid>(cell);
                    if (dataGrid != null)
                    {
                        if (dataGrid.SelectionUnit != DataGridSelectionUnit.FullRow)
                        {
                            if (!cell.IsSelected)
                                cell.IsSelected = true;
                        }
                        else
                        {
                            DataGridRow row =  LogicalTreeWalker.FindParentOfType<DataGridRow>(cell); //FindVisualParent<DataGridRow>(cell);
                            if (row != null && !row.IsSelected)
                            {
                                row.IsSelected = true;
                            }
                        }
                    }
                }
            }    
        }

3.创建一个样式并设置附加属性

        <Style TargetType="{x:Type DataGridCell}">
            <Setter Property="Behaviors:DataGridCellAttachedProperties.IsSingleClickEditMode" Value="True"/>
        </Style>

Answer 4

我有另一个想法，以避免为每个行为创建附加属性：

行为创建者界面：

public interface IBehaviorCreator
{
    Behavior Create();
}

小帮手收集：

public class BehaviorCreatorCollection : Collection<IBehaviorCreator> { }

附加行为的助手类：

public static class BehaviorInStyleAttacher
{
    #region Attached Properties

    public static readonly DependencyProperty BehaviorsProperty =
        DependencyProperty.RegisterAttached(
            "Behaviors",
            typeof(BehaviorCreatorCollection),
            typeof(BehaviorInStyleAttacher),
            new UIPropertyMetadata(null, OnBehaviorsChanged));

    #endregion

    #region Getter and Setter of Attached Properties

    public static BehaviorCreatorCollection GetBehaviors(TreeView treeView)
    {
        return (BehaviorCreatorCollection)treeView.GetValue(BehaviorsProperty);
    }

    public static void SetBehaviors(
        TreeView treeView, BehaviorCreatorCollection value)
    {
        treeView.SetValue(BehaviorsProperty, value);
    }

    #endregion

    #region on property changed methods

    private static void OnBehaviorsChanged(DependencyObject depObj, DependencyPropertyChangedEventArgs e)
    {
        if (e.NewValue is BehaviorCreatorCollection == false)
            return;

        BehaviorCreatorCollection newBehaviorCollection = e.NewValue as BehaviorCreatorCollection;

        BehaviorCollection behaviorCollection = Interaction.GetBehaviors(depObj);
        behaviorCollection.Clear();
        foreach (IBehaviorCreator behavior in newBehaviorCollection)
        {
            behaviorCollection.Add(behavior.Create());
        }
    }

    #endregion
}

现在你的行为，它实现了IBehaviorCreator：

public class SingleClickEditDataGridCellBehavior:Behavior<DataGridCell>, IBehaviorCreator
{
    //some code ...

    public Behavior Create()
    {
        // here of course you can also set properties if required
        return new SingleClickEditDataGridCellBehavior();
    }
}

现在在xaml中使用它：

<Style TargetType="{x:Type DataGridCell}">
  <Setter Property="helper:BehaviorInStyleAttacher.Behaviors" >
    <Setter.Value>
      <helper:BehaviorCreatorCollection>
        <behaviors:SingleClickEditDataGridCellBehavior/>
      </helper:BehaviorCreatorCollection>
    </Setter.Value>
  </Setter>
</Style>

Answer 5

我找不到原始文章，但我能够重新创建效果。

#region Attached Properties Boilerplate

    public static readonly DependencyProperty IsActiveProperty = DependencyProperty.RegisterAttached("IsActive", typeof(bool), typeof(ScrollIntoViewBehavior), new PropertyMetadata(false, OnIsActiveChanged));

    public static bool GetIsActive(FrameworkElement control)
    {
        return (bool)control.GetValue(IsActiveProperty);
    }

    public static void SetIsActive(
      FrameworkElement control, bool value)
    {
        control.SetValue(IsActiveProperty, value);
    }

    private static void OnIsActiveChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var behaviors = Interaction.GetBehaviors(d);
        var newValue = (bool)e.NewValue;

        if (newValue)
        {
            //add the behavior if we don't already have one
            if (!behaviors.OfType<ScrollIntoViewBehavior>().Any())
            {
                behaviors.Add(new ScrollIntoViewBehavior());
            }
        }
        else
        {
            //remove any instance of the behavior. (There should only be one, but just in case.)
            foreach (var item in behaviors.ToArray())
            {
                if (item is ScrollIntoViewBehavior)
                    behaviors.Remove(item);
            }
        }
    }


    #endregion

<Style TargetType="Button">
    <Setter Property="Blah:ScrollIntoViewBehavior.IsActive" Value="True" />
</Style>

Answer 6

将个人行为/触发器声明为资源：

<Window.Resources>

    <i:EventTrigger x:Key="ET1" EventName="Click">
        <ei:ChangePropertyAction PropertyName="Background">
            <ei:ChangePropertyAction.Value>
                <SolidColorBrush Color="#FFDAD32D"/>
            </ei:ChangePropertyAction.Value>
        </ei:ChangePropertyAction>
    </i:EventTrigger>

</Window.Resources>

将它们插入集合中：

<Button x:Name="Btn1" Content="Button">

        <i:Interaction.Triggers>
             <StaticResourceExtension ResourceKey="ET1"/>
        </i:Interaction.Triggers>

</Button>

Answer 7

行为代码需要Visual，因此我们只能在视觉上添加它。所以我能看到的唯一选择是添加到ControlTemplate中的一个元素，以便将行为添加到Style并影响特定控件的所有实例。

Answer 8

文章Introduction to Attached Behaviors in WPF仅使用Style实现附加行为，也可能相关或有帮助。

“附加行为简介”一文中的技术完全避免了使用Style的Interactivity标签。我不知道这是否仅仅是因为它是一种更为过时的技术，或者，如果在某些情况下仍然可以提供一些优先选择。

Answer 9

我喜欢Roman Dvoskin和Jonathan Allen在这个帖子中的答案。当我第一次学习这种技术时，我从this blog post中受益，它提供了有关该技术的更多解释。并且在上下文中查看所有内容，here is the entire source code用于作者在其博客文章中讨论的类。

Answer 10

基于this的答案，我提出了一个更简单的解决方案，只需要一个类，而无需在您的行为中实现其他功能。

public static class BehaviorInStyleAttacher
{
    #region Attached Properties

    public static readonly DependencyProperty BehaviorsProperty =
        DependencyProperty.RegisterAttached(
            "Behaviors",
            typeof(IEnumerable),
            typeof(BehaviorInStyleAttacher),
            new UIPropertyMetadata(null, OnBehaviorsChanged));

    #endregion

    #region Getter and Setter of Attached Properties

    public static IEnumerable GetBehaviors(DependencyObject dependencyObject)
    {
        return (IEnumerable)dependencyObject.GetValue(BehaviorsProperty);
    }

    public static void SetBehaviors(
        DependencyObject dependencyObject, IEnumerable value)
    {
        dependencyObject.SetValue(BehaviorsProperty, value);
    }

    #endregion

    #region on property changed methods

    private static void OnBehaviorsChanged(DependencyObject depObj, DependencyPropertyChangedEventArgs e)
    {
        if (e.NewValue is IEnumerable == false)
            return;

        var newBehaviorCollection = e.NewValue as IEnumerable;

        BehaviorCollection behaviorCollection = Interaction.GetBehaviors(depObj);
        behaviorCollection.Clear();
        foreach (Behavior behavior in newBehaviorCollection)
        {
            // you need to make a copy of behavior in order to attach it to several controls
            var copy = behavior.Clone() as Behavior;
            behaviorCollection.Add(copy);
        }
    }

    #endregion
}

示例用法是

<Style TargetType="telerik:RadComboBox" x:Key="MultiPeriodSelectableRadComboBox">
    <Setter Property="AllowMultipleSelection" Value="True" />
    <Setter Property="behaviors:BehaviorInStyleAttacher.Behaviors">
        <Setter.Value>
            <collections:ArrayList>
                <behaviors:MultiSelectRadComboBoxBehavior
                        SelectedItems="{Binding SelectedPeriods}"
                        DelayUpdateUntilDropDownClosed="True"
                        SortSelection="True" 
                        ReverseSort="True" />
            </collections:ArrayList>
        </Setter.Value>
    </Setter>
</Style>

别忘了添加此xmlns以使用ArrayList：

xmlns:collections="clr-namespace:System.Collections;assembly=mscorlib"

如何在样式设置器中添加混合行为

10 个答案: