我已为按钮创建了一个混合行为。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>
但是，当我尝试：
<Style>
<Setter Property="i:Interaction.Behaviors">
<Setter.Value>
<local:MyBehavior />
</Setter.Value>
</Setter>
</Style>
我遇到了错误
属性"Behaviors"没有可访问的setter。
我曾经遇到同样的问题并找到了解决办法。在我解决问题之后，我发现了这个问题，并且我看到我的解决方案与Mark的解决方案有很多相似之处。不过，这种方法有些不同。
主要问题是行为和触发器与特定对象相关联，因此您不能将相同实例的行为用于多个不同的相关对象。当您在inline XAML中定义行为时，XAML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，该样式可以重复使用于其应用的所有对象，这将在基本行为类中引发异常。事实上，作者花了很多力气防止我们甚至尝试这样做，因为他们知道这样做是行不通的。
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。因此，我们需要自己的行为和触发器集合类。
下一个问题是行为和触发器附加属性没有setter，因此它们只能在内联XAML中添加。我们通过自己的附加属性来解决此问题，以操纵主要的行为和触发器属性。
第三个问题是我们的行为集合仅适用于单个样式目标。我们通过利用一个不常用的XAML特性来解决这个问题，它在每次引用时都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；我们不想用新行为替换旧行为，因为它们可能做完全不同的事情。因此，如果我们接受一旦添加了行为就不能将其删除（这就是行为当前的工作方式），我们可以得出行为和触发器应该是可添加的结论，而这可以通过我们的附加属性来处理。
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>
这个示例使用触发器，但是行为的工作方式相同。在示例中，我们展示了：
下面是一个行为示例，我们的DebugAction。更准确地说，它是一个动作，但是通过滥用语言，我们将行为、触发器和动作称为"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);
}
}
Interaction.Behaviors，您要定位的属性称为 SupplementaryInteraction.Behaviors，因为通过设置此属性，您将向 Interaction.Behaviors 添加行为，并对触发器进行同样的操作。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);
}
}
这就是全部，通过样式应用的完全功能行为和触发器。
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());
}
}
}
}
public class ComboBoxBehaviour : AttachableForStyleBehavior<ComboBox, ComboBoxBehaviour>
{ ... }
<Style TargetType="ComboBox">
<Setter Property="behaviours:ComboBoxBehaviour.IsEnabledForStyle" Value="True"/>
1.创建附加属性
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. 创建一个行为
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>
我有一个新想法，可以避免为每个行为创建附加属性：
行为创建者接口：
public interface IBehaviorCreator
{
Behavior Create();
}
小助手合集：
public class BehaviorCreatorCollection : Collection<IBehaviorCreator> { }
帮助类，用于附加行为：
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接口：
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>
我找不到原始文章，但我能够重新创建这个效果。
#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>
根据这个答案，我做了一个更简单的解决方案，只需要一个类就可以了，不需要在你的行为中实现其他东西。
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
}
样例用法如下：
<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>
xmlns:collections="clr-namespace:System.Collections;assembly=mscorlib"
OnAttached之后，AssociatedObject可能会变成null，我猜测这是由于克隆造成的。我通过在行为中存储一个私有属性来解决这个问题，并引用它。 - Ernie S将个别行为/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>
<Button x:Name="Btn1" Content="Button">
<i:Interaction.Triggers>
<StaticResourceExtension ResourceKey="ET1"/>
</i:Interaction.Triggers>
</Button>
WPF中的附加行为简介一文仅使用样式实现了附加行为，可能也与本文相关或有帮助。
“附加行为简介”文章中的技术完全避免了交互标记，仅使用样式。我不知道这是否只是一种更古老的技术，或者在某些情况下仍然具有一些优点，应该在某些情景下优先选择它。
我喜欢Roman Dvoskin和Jonathan Allen在这个帖子中展示的方法。然而，当我第一次学习这种技术时，我从这篇博客文章中受益，该文章提供了更多关于这种技术的解释。为了全面了解，这里是作者在博客文章中提到的整个源代码。
行为代码期望一个可视化对象，因此我们只能将其添加到可视化对象上。所以我唯一能想到的选择是将其添加到ControlTemplate内的一个元素上，以便将行为添加到样式中并影响特定控件的所有实例。
x:Shared="False"，但我仍然遇到了异常An instance of a Behavior cannot be attached to more than one object at a time。原来在“嵌套”的字典中不支持共享属性，而且ResourceDictionary.MergedDictionaries也算在内。然而，当资源定义在一个单独的 XAML 文件中，该文件只包含一个ResourceDictionary时，我还是让它正常工作了。希望这能帮助到某些人... - Tim Sylvester