How to: Create Radio Group and Respond to Value Selection

• Oct 25, 2019
• 2 minutes to read

This example demonstrates how to programmatically create a radio group, add two items to the collection, initialize their properties and assign a handler to the RadioGroup.SelectedIndexChanged event. The created radio group will be used to control the visibility of a standard button control. This example assumes that a button has already been placed on the form.

The image below shows the example application.

C#

using DevExpress.Utils;
using DevExpress.XtraEditors;
using DevExpress.XtraEditors.Repository;
using DevExpress.XtraEditors.Controls;

// ...
public Form1() {
   InitializeComponent();
   CreateRadioEditors();
}

private void CreateRadioEditors() {
    // Creates and initializes radio group items
    RadioGroupItem item1 = new RadioGroupItem();
    item1.Description = "Hide Button";
    RadioGroupItem item2 = new RadioGroupItem();
    item2.Description = "Show Button";
    // Creates and initializes the radio group
    RadioGroup radioEdit1 = new RadioGroup();
    radioEdit1.Properties.Items.Add(item1);
    radioEdit1.Properties.Items.Add(item2);
    radioEdit1.Name = "radioEdit1";
    radioEdit1.Location = new System.Drawing.Point(button1.Location.X, button1.Location.Y + 40);
    radioEdit1.Width = button1.Width;
    radioEdit1.Height = 100;
    // Sets the editor's selection based on the button's visibility
    if (button1.Visible) radioEdit1.SelectedIndex = 1;
    // Assigns a handler for the SelectedIndexChanged event
    radioEdit1.SelectedIndexChanged += new EventHandler(SelectedIndexChanged);
    this.Controls.Add((Control)radioEdit1);
}

private void SelectedIndexChanged(object sender, System.EventArgs e) {
    RadioGroup edit = sender as RadioGroup;
    if (edit.SelectedIndex == 0) button1.Visible = false;
    else button1.Visible = true;
}

VB.NET

Imports DevExpress.XtraEditors.Repository
Imports DevExpress.XtraEditors.Controls
Imports DevExpress.XtraEditors
Imports DevExpress.Utils

Public Sub New()
   InitializeComponent()
   CreateRadioEditors()
End Sub

Private Sub CreateRadioEditors()
    ' Creates and initializes radio group items
    Dim item1 As New RadioGroupItem()
    item1.Description = "Hide Button"
    Dim item2 As New RadioGroupItem()
    item2.Description = "Show Button"
    ' Creates and initializes the radio group
    Dim radioEdit1 As New RadioGroup()
    radioEdit1.Properties.Items.Add(item1)
    radioEdit1.Properties.Items.Add(item2)
    radioEdit1.Name = "radioEdit1"
    radioEdit1.Location = New System.Drawing.Point(button1.Location.X, button1.Location.Y + 40)
    radioEdit1.Width = button1.Width
    radioEdit1.Height = 100
    ' Sets the editor's selection based on the button's visibility
    If button1.Visible Then
        radioEdit1.SelectedIndex = 1
    End If
    ' Assigns a handler for the SelectedIndexChanged event
    AddHandler radioEdit1.SelectedIndexChanged, AddressOf SelectedIndexChanged
    Me.Controls.Add(CType(radioEdit1, Control))
End Sub

Private Sub SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs)
    Dim edit As RadioGroup = TryCast(sender, RadioGroup)
    If edit.SelectedIndex = 0 Then
        button1.Visible = False
    Else
        button1.Visible = True
    End If
End Sub