Tutorial: Creating a Slide Viewer with RadRotator

Updated on May 7, 2026

The following tutorial demonstrates how to programmatically load images from the Pictures directory for display in RadRotator. The tutorial also integrates a RadStatusStrip control that contains a RadLabelElement.

1. In the default form of a new Windows application:

2. Drop a RadStatusStrip onto the form and set the Dock property to Bottom.

3. Click the RadStatusStrip downward pointing arrow and add a RadLabelElement.

4. Drop a RadRotator on the form and set its Dock property to Fill.

5. Navigate to the code view of the default form.

6. Change the declaration of the form so that it derives from RadForm.

C#

public partial class TutorialCreatingASlideViewerWithRadRotator : RadForm

VB.NET

Partial Class TutorialCreatingASlideViewerWithRadRotator
    Inherits Telerik.WinControls.UI.RadForm

7. Return to the design view of the form. Visual Studio will repaint the form.

8. Click the Events tab of the Properties window and navigate to the Load event of the form. Double-click it to create a Load event handler and replace the code with the following snippet. The code uses the Directory.GetFiles() method to retrieve all .jpg file paths. Each file path is passed to a GetThumbNail() method that returns a RadImageItem, which is added to the RadRotator Items collection. After the image items are loaded, the Start() method is called to begin the animation.

C#

public TutorialCreatingASlideViewerWithRadRotator()
{
    InitializeComponent();
    radRotator1.BeginRotate += new BeginRotateEventHandler(radRotator1_BeginRotate);
}
private void TutorialCreatingASlideViewerWithRadRotator_Load(object sender, EventArgs e)
{
    string myPicturesPath = Environment.GetFolderPath(Environment.SpecialFolder.MyPictures);
    foreach (string fileName in Directory.GetFiles(myPicturesPath, "*.jpg"))
    {
        radRotator1.Items.Add(GetThumbNail(fileName));
    }
    radRotator1.Start(true);
    radRotator1.ShouldStopOnMouseOver = false;
}
private RadImageItem GetThumbNail(string path)
{
    RadImageItem imageItem = new RadImageItem();
    Image image = Image.FromFile(path);
    // workaround to prevent using internal image thumbnail
    image.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);
    image.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);
    // calculate aspect ratio so image is not distorted
    double ratio = 0;
    if (image.Width > image.Height)
    {
        ratio = ClientRectangle.Width / image.Width;
    }
    else
    {
        ratio = ClientRectangle.Height / image.Height;
    }
    int newWidth = (int)(image.Width * ratio);
    int newHeight = (int)(image.Height * ratio);
    imageItem.Image = image.GetThumbnailImage(newWidth, newHeight, null, IntPtr.Zero);
    return imageItem;
}
void radRotator1_BeginRotate(object sender, BeginRotateEventArgs e)
{
    radLabelElement1.Text = String.Format("Rotating from item {0} to {1}", e.From, e.To);
}

VB.NET

Private Sub TutorialCreatingASlideViewerWithRadRotator_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Me.Load
    Dim myPicturesPath As String = Environment.GetFolderPath(Environment.SpecialFolder.MyPictures)
    For Each fileName As String In Directory.GetFiles(myPicturesPath, "*.jpg")
        RadRotator1.Items.Add(GetThumbNail(fileName))
    Next
    RadRotator1.Start(True)
    RadRotator1.ShouldStopOnMouseOver = False
End Sub
Private Function GetThumbNail(ByVal path As String) As RadImageItem
    Dim imageItem As New RadImageItem()
    Dim image As Image = image.FromFile(path)
    ' workaround to prevent using internal image thumbnail
    image.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone)
    image.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone)
    ' calculate aspect ratio so image is not distorted
    Dim ratio As Double = 0
    If image.Width > image.Height Then
        ratio = ClientRectangle.Width / image.Width
    Else
        ratio = ClientRectangle.Height / image.Height
    End If
    Dim newWidth As Integer = Convert.ToInt32(image.Width * ratio)
    Dim newHeight As Integer = Convert.ToInt32(image.Height * ratio)
    imageItem.Image = image.GetThumbnailImage(newWidth, newHeight, Nothing, IntPtr.Zero)
    Return imageItem
End Function
Private Sub RadRotator1_BeginRotate(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.BeginRotateEventArgs) Handles RadRotator1.BeginRotate
    RadLabelElement1.Text = [String].Format("Rotating from item {0} to {1}", e.From, e.[To])
End Sub

9. Press F5 to run the application.