Animating Margin Bottom Silverlight

I'm currently working with animations, I have a grid hiding a search panel, clicking on the search button moves the grid down revealing the search options.

I have this part working the problem is that the grid view takes up all available space so when the search bar is hidden it looks fine but if开发者_如何学Go the search bar is visible then the bottom of the grid goes off the page.

I've been trying to fix this using a margin, when the search bar is revealed the bottom margin is increased, reducing its total size and stopping it going off the bottom of the screen.

I've read a few topics that state that animations on margins are not possible. I've managed to get it partially working with the following code.

<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin" Storyboard.TargetName="Grid">
            <DiscreteObjectKeyFrame KeyTime="0" Value="0"/>
            <DiscreteObjectKeyFrame KeyTime="0:0:0.5" Value="170"/>
        </ObjectAnimationUsingKeyFrames>

The problem is that this applies a margin to all sides of the object, I would only like to apply a margin to the bottom. Unfortunatly the code below doesnt work

Is there a work around for this, or would I have to find another way to move the bottom of the grid up.

Thanks

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The Margin property is of type Thickness, so you should be able to set its component parts as follows:

    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Margin"
                                   Storyboard.TargetName="Grid">
        <DiscreteObjectKeyFrame KeyTime="0" Value="0"/>
        <DiscreteObjectKeyFrame KeyTime="0:0:0.5">
           <DiscreteObjectKeyFrame.Value>
              <Thickness>3,7,5,9</Thickness>
           </DiscreteObjectKeyFrame.Value>
        </DiscreteObjectKeyFrame>
    </ObjectAnimationUsingKeyFrames>

A better alternative might be to position your control using a TranslateTransform, this way you can simple change the X or Y component. I personally think positioning a control via its margin is a bit of a hack!