How can I move an object left and right with silverlight?

Question

I currently have two buttons that say left and right, and I want them to move a square object left and right respectively.

What its currently doing when i press left is moving the square to the left, and if I press left again, it resets from the center and goes left.

I want it so that when I press left, from where ever it is currently to go left and right.

I know the principle is something like get current objects position and add the canvas coordinates respectively but how do I do this?

<UserControl x:Class="phase_2.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="400">
<UserControl.Resources>
    <Storyboard x:Name="scroll_me">
        <DoubleAnimation x:Name="left_ani" To="0" Duration="0:0:01" Storyboard.TargetName="Rect_Animate" Storyboard.TargetProperty="(Canvas.Left)">
            <DoubleAnimation.EasingFunction>
                <PowerEase EasingMode="EaseOut"></PowerEase>
            </DoubleAnimation.EasingFunction>
        </DoubleAnimation>
    </Storyboard>
    <Storyboard x:Name="scroll_me2">
        <DoubleAnimation x:Name="right_ani" To="200" Duration="0:0:01" Storyboard.TargetName="Rect_Animate" Storyboard.TargetProperty="(Canvas.Left)">
            <DoubleAnimation.EasingFunction>
                <PowerEase EasingMode="EaseOut"></PowerEase>
            </DoubleAnimation.EasingFunction>
        </DoubleAnimation>
    </Storyboard>
</UserControl.Resources>

<Grid x:Name="LayoutRoot" Background="White">
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="1*"/>
        <ColumnDefinition Width="2*"/>
        <ColumnDefinition Width="1*"/>
    </Grid.ColumnDefinitions>
    <Grid.RowDefinitions>
        <RowDefinition Height="1*"/>
        <RowDefinition Height="35"/>
        <RowDefinition Height="1*"/>
    </Grid.RowDefinitions>
    <Canvas Grid.Column="1" Grid.Row="1" x:Name="canvas1">
        <Rectangle x:Name="Rect_Animate" Width="35" Height="35" Fill="Red" Canvas.Left="80" />
    </Canvas>
    <Button x:Name="left_btn" Width="35" Height="35" Content="L" Grid.Column="0" Grid.Row="1" Click="left_btn_Click"/>
    <Button x:Name="right_btn" Width="35" Height="35" Content="R" Grid.Column="2" Grid.Row="1" Click="right_btn_Click"/>
</Grid>

Answer 1

Only if your object is contained in a Canvas, which in general is not a great layout practice - it isn't flexible.

If you're placing items in a Grid instead, you can do exactly what the designer tools like Blend do: adjust the Margin of any item you want to move. You can have negative margins.