WPF: Add a dropshadow effect to an element from code-behind

I thought this would be so开发者_如何学编程mething simple but so far i found nothing. How do you do it?

The accepted answer is now obsolete. Now you may use:

UIElement uie = ...
uie.Effect = 
    new DropShadowEffect
    {
        Color = new Color {A = 255, R = 255, G = 255, B = 0},
        Direction = 320,
        ShadowDepth = 0,
        Opacity = 1
    };

To achieve the exact same effect as the accepted answer.

just try this

// Get a reference to the Button.
Button myButton = new Button();

// Initialize a new DropShadowBitmapEffect that will be applied
// to the Button.
DropShadowBitmapEffect myDropShadowEffect  = new DropShadowBitmapEffect();
// Set the color of the shadow to Black.
Color myShadowColor = new Color();
myShadowColor.ScA = 1;
myShadowColor.ScB  = 0;
myShadowColor.ScG  = 0;
myShadowColor.ScR  = 0;
myDropShadowEffect.Color = myShadowColor;

// Set the direction of where the shadow is cast to 320 degrees.
myDropShadowEffect.Direction = 320; 

// Set the depth of the shadow being cast.
myDropShadowEffect.ShadowDepth = 25; 

// Set the shadow softness to the maximum (range of 0-1).
myDropShadowEffect.Softness = 1;
// Set the shadow opacity to half opaque or in other words - half transparent.
// The range is 0-1.
myDropShadowEffect.Opacity = 0.5; 

// Apply the bitmap effect to the Button.
myButton.BitmapEffect = myDropShadowEffect; 

@Gleno's answer helped me the most. In my case I was using it for visual feedback on a missed form item. To then remove the dropshadow I used:

myComboBox.ClearValue(EffectProperty);

in a selectionChanged event.

Hope this helps someone. I had to search for a bit.