How can I attach two attached behaviors to one XAML element?

问题

I've implemented the attached command behavior pattern found here and it works well to allow e.g. a Border to have a left- or right-click event that fires in the ViewModel:

XAML:

<Border Background="Yellow" Width="350" Margin="0,0,10,0" Height="35" CornerRadius="2"
        c:CommandBehavior.Event="MouseLeftButtonDown" 
        c:CommandBehavior.Command="{Binding PressedLeftButton}"
        c:CommandBehavior.CommandParameter="MainBorder123">
    <TextBlock Text="this is the click area"/>
</Border>

Code Behind:

public ICommand PressedLeftButton { get; private set; }

public MainViewModel()
{

    Output = "original value";

    PressedLeftButton = new SimpleCommand
    {
        ExecuteDelegate = parameterValue => {
            Output = String.Format("left mouse button was pressed at {0} and sent the parameter value \"{1}\"", DateTime.Now.ToString(), parameterValue.ToString());
        }
    };
}

However, how do I attach two attached behaviors to one element, e.g. I want to do something like the following but it of course gives me an error:

<Border Background="Yellow" Width="350" Margin="0,0,10,0" Height="35" CornerRadius="2"
        c:CommandBehavior.Event="MouseLeftButtonDown" 
        c:CommandBehavior.Command="{Binding PressedLeftButton}"
        c:CommandBehavior.CommandParameter="MainBorder123"
        c:CommandBehavior.Event="MouseRightButtonDown" 
        c:CommandBehavior.Command="{Binding PressedRighttButton}"
        c:CommandBehavior.CommandParameter="MainBorder123"
        >

回答1:

The link you sent contains that very answer. You can use the CommandBehaviorCollection.Behaviors capabilities in ACB v2.

   <Border Background="Yellow" Width="350" Margin="0,0,10,0" Height="35" CornerRadius="2" x:Name="test">
       <local:CommandBehaviorCollection.Behaviors>
               <local:BehaviorBinding Event="MouseLeftButtonDown" Action="{Binding DoSomething}" CommandParameter="An Action on MouseLeftButtonDown"/>
               <local:BehaviorBinding Event="MouseRightButtonDown" Command="{Binding SomeCommand}" CommandParameter="A Command on MouseRightButtonDown"/>
       </local:CommandBehaviorCollection.Behaviors>
       <TextBlock Text="MouseDown on this border to execute the command"/>
   </Border>

回答2:

"that was it, thanks, funny though that my XAML editor gives me the error "The attachable property 'Behaviors' was not found in type 'CommandBehaviorCollection'." although I can run and compile it fine, why is that?"

The reason is that the code that allows the command behavior collection (which is an attached property collection) is actualy sort of a XAML loophole. You can read more about that here: http://wekempf.spaces.live.com/blog/cns!D18C3EC06EA971CF!468.entry?sa=276442122

来源：https://stackoverflow.com/questions/926451/how-can-i-attach-two-attached-behaviors-to-one-xaml-element

标签

wpf

mvvm

attachedbehaviors