How to: Make an Object Follow the Mouse Pointer
This example shows how to change the dimensions of an object when the mouse pointer moves on the screen.
The example includes an Extensible Application Markup Language (XAML) file that creates the user interface (UI) and a code-behind file that creates the event handler. For the complete sample, see Moving an Object with the Mouse Pointer Sample.
Example
The following XAML creates the UI, which consists of an Ellipse inside of a StackPanel, and attaches the event handler for the MouseMove event.
<Window x:Class="WCSamples.Window1"
xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
Title="mouseMoveWithPointer"
Height="400"
Width="500"
>
<Canvas MouseMove="MouseMoveHandler"
Background="LemonChiffon">
<Ellipse Name="ellipse" Fill="LightBlue"
Width="100" Height="100"/>
</Canvas>
</Window>
The following code behind creates the MouseMove event handler. When the mouse pointer moves, the height and the width of the Ellipse are increased and decreased.
// raised when the mouse pointer moves.
// Expands the dimensions of an Ellipse when the mouse moves.
private void MouseMoveHandler(object sender, MouseEventArgs e)
{
// Get the x and y coordinates of the mouse pointer.
Point position = e.GetPosition(this);
double pX = position.X;
double pY = position.Y;
// Sets the Height/Width of the circle to the mouse coordinates.
ellipse.Width = pX;
ellipse.Height = pY;
}
' raised when the mouse pointer moves.
' Expands the dimensions of an Ellipse when the mouse moves.
Sub OnMouseMoveHandler(ByVal sender As Object, ByVal e As MouseEventArgs)
'Get the x and y coordinates of the mouse pointer.
Dim position As System.Windows.Point
position = e.GetPosition(Me)
Dim pX As Double
pX = position.X
Dim pY As Double
pY = position.Y
'Set the Height and Width of the Ellipse to the mouse coordinates.
ellipse1.Height = pY
ellipse1.Width = pX
End Sub