<Rectangle Width="20" Height="20" x:Name="cursor">
<Rectangle.Triggers>
<EventTrigger RoutedEvent="Canvas.Loaded">
<BeginStoryboard>
<Storyboard>
<DoubleAnimation
Storyboard.TargetName="rotate" Storyboard.TargetProperty="Angle"
By="360" Duration="00:00:03" RepeatBehavior="Forever"/>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Rectangle.Triggers>
<Rectangle.RenderTransform>
<RotateTransform x:Name="rotate" CenterX="10" CenterY="10"/>
</Rectangle.RenderTransform>
<Rectangle.Fill>
<LinearGradientBrush>
<GradientStop Color="White" Offset="0"/>
<GradientStop Color="Red" Offset=".5"/>
<GradientStop Color="Black" Offset="1"/>
</LinearGradientBrush>
</Rectangle.Fill>
</Rectangle>

public void Page_Loaded(object o, EventArgs e) {
// Required to initialize variables
            InitializeComponent();
this.Cursor = Cursors.None;
}

public void OnMouseMove(object sender, MouseEventArgs e) {
double x = e.GetPosition(this).X;
double y = e.GetPosition(this).Y;
if (x <= 20 || x >= this.Width - 20 || y <= 20 || y >= this.Height - 20)
this.cursor.Visibility = Visibility.Collapsed;
else
this.cursor.Visibility = Visibility.Visible;
this.cursor.SetValue<double>(Canvas.LeftProperty, x);
this.cursor.SetValue<double>(Canvas.TopProperty, y);
}