Getting Started with WinForms MultiColumnComboBox

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.

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.

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;
}

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.

See Also

• Design Time
  
• Data Binding
  

Telerik UI for WinForms Learning Resources

• Telerik UI for WinForms MultiColumnComboBox Component
• Getting Started with Telerik UI for WinForms Components
• Telerik UI for WinForms Setup
• Telerik UI for WinForms Application Modernization
• Telerik UI for WinForms Visual Studio Templates
• Deploy Telerik UI for WinForms Applications
• Telerik UI for WinForms Virtual Classroom(Training Courses for Registered Users)
• Telerik UI for WinForms License Agreement)