来自C＃而不是XAML的ConstrainToParentBounds

Question

To constrain a draggable object in XAML to its parent container I can do the following.

<Image Name="myImage" Source="Images/MyImage.png">
    <i:Interaction.Behaviors>
        <el:MouseDragElementBehavior ConstrainToParentBounds="True"/>
    </i:Interaction.Behaviors>
</Image>

How would I do this in C#? My best guess which appears to be incorrect was:

myImage.SetValue(MouseDragElementBehavior.ConstrainToParentBoundsProperty, true);

Answer 1

This is how you get the behaviors from code. You can change to property on the returned object.

System.Windows.Interactivity.Interaction.GetBehaviors(myImage)

Answer 2

As Andras stated, I needed to get the behavior collection. However, I also needed to add a new event since the MouseDrageElementBehavior was not already in the behavior collection.

BehaviorCollection behaviors = Interaction.GetBehaviors(myImage);
var mouseDragBehavior = new MouseDragElementBehavior();
mouseDragBehavior.ConstrainToParentBounds = true;
behaviors.Add(mouseDragBehavior);