Silverlight 4.0 feature - Mouse wheel event

Objective

In this article, I am going to give a basic introduction of Mouse wheel event in Silverlight 4.0.

Introduction

Silverlight 4.0 has been introduced Mouse wheel event. Now on mouse wheel event can be captured. And the event can be raised for any silver light control.

In below image you can see, MouseWheel event has been included.



If you see the description above it is saying

"This event occurs, when user rotates the mouse wheel while pointer is over a UI Elements "

Sample

I have an image on my silver light page.

<UserControl x:Class="MouseWheelevent.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">
    <Grid x:Name="LayoutRoot" Background="Azure" Height="auto" Width="auto">
        <Image x:Name="MyImage" Width="300" Height="400" Source="a.jpg" />
    </Grid>
</UserControl>

Output of above



Now we are going to resize the image on mouse wheel event.

Adding Mouse Wheel event with image

MyImage.MouseWheel += new MouseWheelEventHandler(mymousewheelevent);

Handling the event

  void mymousewheelevent(object sender, MouseWheelEventArgs e)
        {
            double  height = MyImage.Height;
            double  width = MyImage.Width;
            int delta = e.Delta;
            height += delta;
            width += delta / 2;
            MyImage.Height = height > 650 ? 400 : height;
            MyImage.Width = width > 600 ? 300 : width;
        }

Explanation

• Just saving current height and width in variables.
• Using Delta method on event args , change could be captured.
• Then just setting the dimension of image with some logic.

Output

Click on image and scroll the mouse ball. Image size will be change.



So, we can attach the Mouse wheel event with any control.

Conclusion

In this article, I gave basic introduction of MouseWheel event in Silverlight 4.0. Thanks for reading.