WPF自定义行为Behavior，实现双击控件复制文本

WPF引用xmlns:i=”clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity”后可以设置很多自定义的行为：

       <i:Interaction.Triggers\>
            <i:EventTrigger EventName\="ValueChanged"\>
                <i:InvokeCommandAction Command\="{Binding ValueChangedCommand}" />
            </i:EventTrigger\>
        </i:Interaction.Triggers\>

<UserControl.Resources>
<ControlTemplate x:Key=“trackThumb” TargetType=“{x:Type Slider}”>
<Border Background=“{TemplateBinding Background}” BorderBrush=“{TemplateBinding BorderBrush}” BorderThickness=“{TemplateBinding BorderThickness}”>
<Grid>
<Track x:Name=“PART_Track”>
<Track.Thumb>
<Thumb Width=“10”>
<i:Interaction.Triggers>
<i:EventTrigger EventName=“DragCompleted”>
<i:InvokeCommandAction Command=“{Binding ValueChangedCommand}” />
</i:EventTrigger>
</i:Interaction.Triggers>
</Thumb>
</Track.Thumb>
</Track>
</Grid>
</Border>
</ControlTemplate>
</UserControl.Resources>

当时当我们有一些自定义的需求时，需要自定义行为，例如给每个控件添加一个双击复制文本的行为。

1. 定义行为

public class MouseDoubleClickCopyTextBehavior : Behavior {
///

/// 需要复制的内容
///

public string CopyText
{ get { return (string)GetValue(CopyTextProperty); } set { SetValue(CopyTextProperty, value); }
} public static readonly DependencyProperty CopyTextProperty = DependencyProperty.Register(“CopyText”, typeof(string), typeof(MouseDoubleClickCopyTextBehavior), new PropertyMetadata(null)); protected override void OnAttached()
{ base.OnAttached();
AssociatedObject.PreviewMouseLeftButtonDown += AssociatedObject_PreviewMouseLeftButtonDown;
} protected override void OnDetaching()
{ base.OnDetaching();
AssociatedObject.PreviewMouseLeftButtonDown -= AssociatedObject_PreviewMouseLeftButtonDown;
} void AssociatedObject_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{ if (e.ClickCount >= 2)
Clipboard.SetDataObject(CopyText);
}

2. 控件绑定行为