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Getting Started with WinForms MultiColumnComboBox

Updated over 6 months ago

This tutorial will help you to quickly get started using the control.

Adding Telerik Assemblies Using NuGet

To use RadMultiColumnComboBox when working with NuGet packages, install the Telerik.UI.for.WinForms.AllControls package. The package target framework version may vary.

Read more about NuGet installation in the Install using NuGet Packages article.

With the 2025 Q1 release, the Telerik UI for WinForms has a new licensing mechanism. You can learn more about it here.

Adding Assembly References Manually

When dragging and dropping a control from the Visual Studio (VS) Toolbox onto the Form Designer, VS automatically adds the necessary assemblies. However, if you're adding the control programmatically, you'll need to manually reference the following assemblies:

Telerik.Licensing.Runtime
Telerik.WinControls
Telerik.WinControls.GridView
Telerik.WinControls.UI
TelerikCommon

The Telerik UI for WinForms assemblies can be install by using one of the available installation approaches.

Defining the RadMultiColumnComboBox

The following tutorial demonstrates how to setup RadMultiColumnComboBox and retrieve the selected text and image.

1. Add a RadMultiColumnComboBox and a RadStatusStrip to a RadForm.
2. By using the Visual Studio Properties grid and the Data Source Configuration Wizard, set the DataSource, ValueMember and DisplayMember properties of RadMultiColumnComboBox. Thus, RadMultiColumnComboBox will be bound to the Northwind.Employees table.

WinForms RadMultiColumnComboBox Properties Dialog

3. Add a RadImageButtonElement and a RadLabelElement to the RadStatusStrip. 4. In the Visual Studio Properties grid, select the Events tab and double click the SelectedIndexChanged event in order to generate an event handler.

C#
        
private void radMultiColumnComboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    if (this.radMultiColumnComboBox1.SelectedIndex > -1)
    {
        Image img = GetImageFromBytes(this.radMultiColumnComboBox1.EditorControl.CurrentRow.Cells["Photo"].Value as byte[]);
        this.radImageButtonElement1.Image = img.GetThumbnailImage(32, 32, null, IntPtr.Zero);
        this.radLabelElement1.Text = this.radMultiColumnComboBox1.Text;
    }
}
        
private Image GetImageFromBytes(byte[] bytes)
{
    Image result = null;
    System.IO.MemoryStream stream = null;
    try
    {
        stream = new System.IO.MemoryStream(bytes, 78, bytes.Length - 78);
        result = Image.FromStream(stream);
    }
    catch
    {
        try
        {
            stream = new System.IO.MemoryStream(bytes, 0, bytes.Length);
            result = Image.FromStream(stream);
        }
        catch
        {
            result = null;
        }
    }
    finally
    {
        if (stream != null)
            stream.Close();
    }
    return result;
}
VB.NET
Private Sub RadMultiColumnComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles RadMultiColumnComboBox1.SelectedIndexChanged
    If Me.RadMultiColumnComboBox1.SelectedIndex > -1 Then
        Dim img As Image = GetImageFromBytes(TryCast(Me.RadMultiColumnComboBox1.EditorControl.CurrentRow.Cells("Photo").Value, Byte()))
        Me.RadImageButtonElement1.Image = img.GetThumbnailImage(32, 32, Nothing, IntPtr.Zero)
        Me.RadLabelElement1.Text = Me.RadMultiColumnComboBox1.Text
    End If
End Sub
Private Function GetImageFromBytes(bytes As Byte()) As Image
    Dim result As Image = Nothing
    Dim stream As System.IO.MemoryStream = Nothing
    Try
        stream = New System.IO.MemoryStream(bytes, 78, bytes.Length - 78)
        result = Image.FromStream(stream)
    Catch
        Try
            stream = New System.IO.MemoryStream(bytes, 0, bytes.Length)
            result = Image.FromStream(stream)
        Catch
            result = Nothing
        End Try
    Finally
        If stream IsNot Nothing Then
            stream.Close()
        End If
    End Try
    Return result
End Function

5. Open the Property Builder by using the Smart Tag and uncheck some of the columns in order to control which columns to be visible. 6. Press F5 to run the application and change the selection in RadMultiColumnComboBox.

WinForms RadMultiColumnComboBox Getting Started

Getting Started with WinForms MultiColumnComboBox

Adding Telerik Assemblies Using NuGet

Adding Assembly References Manually

Defining the RadMultiColumnComboBox

See Also

Telerik UI for WinForms Learning Resources