Customization

Updated on May 7, 2026

RadTrackBar introduces the TickFormatting and LableFormatting events in order to facilitate the standard customization through the element tree of the control. Below you will find a scenario that will increase your knowledge about RadTrackBar's API. Basically, we will customize RadTrackBar to use it as a selection tool for dates in a month:

Dates selection example

C#

public TrackBarCustomization()
{
    InitializeComponent();

    this.radTrackBar1.Maximum = DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month);
    this.radTrackBar1.Minimum = 1;
    this.radTrackBar1.LargeTickFrequency = 1;
    this.radTrackBar1.LabelStyle = Telerik.WinControls.UI.TrackBarLabelStyle.Both;
    this.radTrackBar1.TrackBarMode = Telerik.WinControls.UI.TrackBarRangeMode.Range;
    this.radTrackBar1.Ranges[0].End = 7;
    this.radTrackBar1.Ranges.Add(new Telerik.WinControls.UI.TrackBarRange(18, 23));

    this.radTrackBar1.TickFormatting += new Telerik.WinControls.UI.TickFormattingEventHandler(radTrackBar1_TickFormatting);
    this.radTrackBar1.LabelFormatting += new Telerik.WinControls.UI.LabelFormattingEventHandler(radTrackBar1_LabelFormatting);
}


void radTrackBar1_TickFormatting(object sender, TickFormattingEventArgs e)
{
    //since the ticks are zero-bazed, just add 1 to simulate days
    int day = e.TickNumber + 1;

    DateTime dt = new DateTime(DateTime.Now.Year, DateTime.Now.Month, day);

    //color sat & sun
    if (dt.DayOfWeek == DayOfWeek.Sunday || dt.DayOfWeek == DayOfWeek.Saturday)
    {
        e.TickElement.Line1.BackColor = Color.Orange;
        e.TickElement.Line2.BackColor = Color.Yellow;
    }

    //offset the bottom ticket
    if (e.TickElement.IsTopLeft)
    {
        e.TickElement.PositionOffset = new SizeF(0, 5);
    }

    //set the minimum size of the ticks
    e.TickElement.MinSize = new Size(2, 5);
}

void radTrackBar1_LabelFormatting(object sender, LabelFormattingEventArgs e)
{
    DateTime dt = new DateTime(DateTime.Now.Year, DateTime.Now.Month, int.Parse(e.LabelElement.Text));

    //colorize the sat & sun
    if (dt.DayOfWeek == DayOfWeek.Sunday || dt.DayOfWeek == DayOfWeek.Saturday)
    {
        e.LabelElement.ForeColor = Color.Red;
    }

    //make the top labels display the days
    if (e.LabelElement.IsTopLeft)
    {
        e.LabelElement.Text = dt.ToString("ddd", new CultureInfo("en-US"));
    }
}

VB.NET

    Public Sub New()
        InitializeComponent()

        Me.RadTrackBar1.Maximum = DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month)
        Me.RadTrackBar1.Minimum = 1
        Me.RadTrackBar1.LargeTickFrequency = 1
        Me.RadTrackBar1.LabelStyle = Telerik.WinControls.UI.TrackBarLabelStyle.Both
        Me.RadTrackBar1.TrackBarMode = Telerik.WinControls.UI.TrackBarRangeMode.Range
        Me.RadTrackBar1.Ranges(0).[End] = 7
        Me.RadTrackBar1.Ranges.Add(New Telerik.WinControls.UI.TrackBarRange(18, 23))

        AddHandler Me.RadTrackBar1.TickFormatting, AddressOf radTrackBar1_TickFormatting
        AddHandler Me.RadTrackBar1.LabelFormatting, AddressOf radTrackBar1_LabelFormatting

    End Sub


    Private Sub radTrackBar1_TickFormatting(sender As Object, e As TickFormattingEventArgs)
        'since the ticks are zero-bazed, just add 1 to simulate days
        Dim day As Integer = e.TickNumber + 1

        Dim dt As New DateTime(DateTime.Now.Year, DateTime.Now.Month, day)

        'color sat & sun
        If dt.DayOfWeek = DayOfWeek.Sunday OrElse dt.DayOfWeek = DayOfWeek.Saturday Then
            e.TickElement.Line1.BackColor = Color.Orange
            e.TickElement.Line2.BackColor = Color.Yellow
        End If

        'offset the bottom ticket
        If e.TickElement.IsTopLeft Then
            e.TickElement.PositionOffset = New SizeF(0, 5)
        End If

        'set the minimum size of the ticks
        e.TickElement.MinSize = New Size(2, 5)
    End Sub

    Private Sub radTrackBar1_LabelFormatting(sender As Object, e As LabelFormattingEventArgs)
       Dim dt As New DateTime(DateTime.Now.Year, DateTime.Now.Month, Integer.Parse(e.LabelElement.Text))

        'colorize the sat & sun
        If dt.DayOfWeek = DayOfWeek.Sunday OrElse dt.DayOfWeek = DayOfWeek.Saturday Then
            e.LabelElement.ForeColor = Color.Red
        End If

        'make the top labels display the days
        If e.LabelElement.IsTopLeft Then
            e.LabelElement.Text = dt.ToString("ddd", New CultureInfo("en-US"))
        End If
    End Sub

See Also

• Themes
• Accessing and Customizing Elements