Telerik UI for Windows Phone by Progress

RadPickerBox allows you to customize the way the Popup Window gets animated while opening or closing. This is done by setting the PopupOpenAnimationa and the PopupCloseAnimation properties to the desired RadAnimation object. Here is an example.

CopyXAML
<telerikPrimitives:RadPickerBox x:Name="radPickerBox">
<telerikPrimitives:RadPickerBox.PopupOpenAnimation>
<telerikCore:RadFadeAnimation StartOpacity="0.0" EndOpacity="1.0" Duration="0:0:0.3" />
</telerikPrimitives:RadPickerBox.PopupOpenAnimation>
<telerikPrimitives:RadPickerBox.PopupCloseAnimation>
<telerikCore:RadFadeAnimation StartOpacity="1.0" EndOpacity="0.0" Duration="0:0:0.3" />
</telerikPrimitives:RadPickerBox.PopupCloseAnimation>
</telerikPrimitives:RadPickerBox>

Additionally you can disable the animating of the Popup Window by setting the IsPopupAnimationEnabled property of the RadPickerBox control to False.

CopyXAML
<telerikPrimitives:RadPickerBox x:Name="radPickerBox" IsPopupAnimationEnabled="True"></telerikPrimitives:RadPickerBox>