DropShadowEffect Class

<StackPanel>
    <Button Content="Drop Shadow Under Me" Width="200" Margin="10">
        <Button.Effect>

            <!-- The DropShadowEffect has several important properties that
           determine characteristics of the drop shadow: 
         - Color: Specifies the color of the drop shadow. Default is black.
         - ShadowDepth: Specifies how far displaced the shadow is from the object
           casting the shadow. Default is 5.
         - Direction: Specifies in what direction the shadow is cast from the object. 
           It is an angle between 0 and 360 with 0 starting on the right hand side 
           and moving counter-clockwise around the object. The value of 320 in this 
           example casts the shadow on the lower right hand side of the button. The default
           is 315.
         - BlurRadius: Specifies how blurry the shadow is. The range is between 0 and 1 with 1
           being the softest. Default is 5. 
         - Opacity: Specifies how transparent the shadow is. The range is between 0 
           and 1 with 1 being fully opaque and 0 fully transparent (not visible). The
           default is 1. -->
            <DropShadowEffect Color="Black" Direction="320" ShadowDepth="25" 
             BlurRadius="5" Opacity="0.5" />
        </Button.Effect>
    </Button>
</StackPanel>

<StackPanel x:Name="LayoutRoot" Background="White">
    <StackPanel.Resources>
        <Style x:Name="buttonStyle" TargetType="Button" >
            <Style.Setters>
                <Setter Property = "Effect" >
                    <Setter.Value>
                        <DropShadowEffect Color="Black" Direction="320"  
                         ShadowDepth="25" BlurRadius="5" Opacity="0.5" />

                    </Setter.Value>
                </Setter>
            </Style.Setters>
        </Style>
    </StackPanel.Resources>
    <Button Width="200" Height="30" Style="{StaticResource buttonStyle}" 
            Margin="20" Content="Drop Shadow Under Me" />
</StackPanel>

<StackPanel>
    <Button Click="ApplyDropShadow" Width="200" Margin="20" 
            Content="Click!" />
</StackPanel>

Private Sub ApplyDropShadow(ByVal sender As Object, ByVal e As RoutedEventArgs)

    Dim myButton As Button = CType(sender, Button)

    ' Initialize a new DropShadowEffect that will be applied
    ' to the Button.
    Dim myDropShadowEffect As DropShadowEffect = New DropShadowEffect

    ' Set the color of the shadow to Black.
    Dim myShadowColor As Color = New Color
    myShadowColor.A = 255

    ' Note that the alpha value is ignored by Color property. 
    ' The Opacity property is used to control the alpha.
    myShadowColor.B = 50
    myShadowColor.G = 50
    myShadowColor.R = 50
    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.BlurRadius = 6

    ' Set the shadow opacity to half opaque or in other words - half transparent.
    ' The range is 0-1.
    myDropShadowEffect.Opacity = 0.5

    ' Apply the effect to the Button.
    myButton.Effect = myDropShadowEffect
End Sub

private void ApplyDropShadow(object sender, RoutedEventArgs e)
{
    Button myButton = (Button)sender;


    // Initialize a new DropShadowEffect that will be applied
    // to the Button.
    DropShadowEffect myDropShadowEffect = new DropShadowEffect();

    // Set the color of the shadow to Black.
    Color myShadowColor = new Color();
    myShadowColor.A = 255; // Note that the alpha value is ignored by Color property. 
    // The Opacity property is used to control the alpha.
    myShadowColor.B = 50;
    myShadowColor.G = 50;
    myShadowColor.R = 50;

    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.BlurRadius = 6;

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

    // Apply the effect to the Button.
    myButton.Effect = myDropShadowEffect;
}

<StackPanel>
    <StackPanel.Resources>
        <Storyboard x:Name="myStoryboard">

            <!-- Animate shadow depth of the effect. -->
            <DoubleAnimation
           Storyboard.TargetName="myDropShadowEffect"
           Storyboard.TargetProperty="ShadowDepth"
           To="30" Duration="0:0:0.5"
           AutoReverse="True" />

            <!-- Animate shadow BlurRadius of the effect. As 
               the Button appears to get farther from the shadow,  
               the shadow blurs. -->
            <DoubleAnimation
           Storyboard.TargetName="myDropShadowEffect"
           Storyboard.TargetProperty="BlurRadius"
           To="10" Duration="0:0:0.5"
           AutoReverse="True" />

            <!-- Animate ScaleX of button. -->
            <DoubleAnimation
           Storyboard.TargetName="myScaleTransform"
           Storyboard.TargetProperty="ScaleX"
           To="1.5" Duration="0:0:0.5"
           AutoReverse="True" />

            <!-- Animate ScaleY of button. -->
            <DoubleAnimation
           Storyboard.TargetName="myScaleTransform"
           Storyboard.TargetProperty="ScaleY"
           To="1.5" Duration="0:0:0.5"
           AutoReverse="True" />

            <!-- Move button in the X direction. -->
            <DoubleAnimation
           Storyboard.TargetName="myTranslateTransform"
           Storyboard.TargetProperty="X"
           To="-30" Duration="0:0:0.5"
           AutoReverse="True" />

            <!-- Move button in the Y direction. -->
            <DoubleAnimation
           Storyboard.TargetName="myTranslateTransform"
           Storyboard.TargetProperty="Y"
           To="-30" Duration="0:0:0.5"
           AutoReverse="True" />

        </Storyboard>

    </StackPanel.Resources>
    <Button Content="Click!" Click="StartAnimation" Width="200"
            Margin="60">
        <Button.Effect>
            <DropShadowEffect x:Name="myDropShadowEffect" />
        </Button.Effect>
        <Button.RenderTransform>
            <TransformGroup>
              <TranslateTransform x:Name="myTranslateTransform" />
              <ScaleTransform x:Name="myScaleTransform" />
            </TransformGroup>
        </Button.RenderTransform>
    </Button>
</StackPanel>

Private Sub StartAnimation(ByVal sender As Object, ByVal args As RoutedEventArgs)
    myStoryboard.Begin()
End Sub

private void StartAnimation(object sender, RoutedEventArgs args)
{
    myStoryboard.Begin();
}