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ListControl.SelectedValueChanged Event

Occurs when the SelectedValue property changes.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

public event EventHandler SelectedValueChanged
/** @event */
public void add_SelectedValueChanged (EventHandler value)

/** @event */
public void remove_SelectedValueChanged (EventHandler value)

JScript supports the use of events, but not the declaration of new ones.

When you create a ListControl delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see Events and Delegates

The following code example is a complete application that shows how you can use DataSource, DisplayMember, ValueMember, and SelectedValue members of the ListControl class as implemented by the ListBox class. The example loads an ArrayList and the list box. The example also uses the SelectedValueChanged event to fill in a text box when the user selects an item in the list box. The text box is filled with the data associated with the selected item.

using System;
using System.Windows.Forms ;
using System.Drawing ;
using System.Collections ;


namespace MyListControlSample
{

    public class USState
    {
        private string myShortName ;
        private string myLongName ;
    
        public  USState(string strLongName, string strShortName)
        {

            this.myShortName = strShortName;
            this.myLongName = strLongName;
        }

        public string ShortName
        {
            get
            {
                return myShortName;
            }
        }

        public string LongName
        {
        
            get
            {
                return myLongName ;
            }
        }

        public override string ToString()
        {
            return this.ShortName + " - " + this.LongName;
        }
    }

    public class ListBoxSample3:Form
    {
        private ListBox ListBox1 = new ListBox();
        private TextBox textBox1 = new TextBox() ;
        
        [STAThread]
        static void Main() 
        {
            Application.Run(new ListBoxSample3()) ;
        }

        public ListBoxSample3()
        {
        
            this.ClientSize = new Size(292, 181) ;
            this.Text = "ListBox Sample3" ;

            ListBox1.Location = new Point(24, 16) ;
            ListBox1.Name = "ListBox1" ;
            ListBox1.Size = new Size(232, 130) ;
            


            textBox1.Location = new Point(24, 160) ;
            textBox1.Name = "textBox1" ;
            textBox1.Size = new Size(240, 24) ;
            this.Controls.AddRange(new Control[] {ListBox1, textBox1}) ;

            // Populates the list box using DataSource. 
            // DisplayMember is used to display just the long name of each state.
            ArrayList USStates = new ArrayList()    ;
            USStates.Add(new USState("Alabama", "AL"));
            USStates.Add(new USState("Washington", "WA"))  ; 
            USStates.Add(new USState("West Virginia", "WV"));
            USStates.Add(new USState("Wisconsin", "WI")) ;
            USStates.Add(new USState("Wyoming", "WY"));

            ListBox1.SelectedValueChanged += new EventHandler(ListBox1_SelectedValueChanged);
            ListBox1.DataSource = USStates ;
            ListBox1.DisplayMember = "LongName"      ;
            ListBox1.ValueMember = "ShortName" ;

        }
        private void InitializeComponent()
        {
        
        }

        private void ListBox1_SelectedValueChanged(object sender, EventArgs e)
        {
            if (ListBox1.SelectedIndex != -1)
                textBox1.Text = ListBox1.SelectedValue.ToString();
        }
    }
}

package MyListControlSample;

import System.*;
import System.Windows.Forms.*;
import System.Drawing.*;
import System.Collections.*;

public class USState
{
    private String myShortName;
    private String myLongName;

    public USState(String strLongName, String strShortName)
    {
        this.myShortName = strShortName;
        this.myLongName = strLongName;
    } //USState

    /** @property
     */
    public String get_ShortName()
    {
        return myShortName;
    }//get_ShortName

    /** @property 
     */
    public String get_LongName()
    {
        return myLongName;
    }//get_LongName

    public String ToString()
    {
        return this.get_ShortName() + " - " + this.get_LongName();
    } //ToString
} //USState

public class ListBoxSample3 extends Form
{
    private ListBox listBox1 = new ListBox();
    private TextBox textBox1 = new TextBox();

    /** @attribute STAThread()
     */
    public static void main(String[] args)
    {
        Application.Run(new ListBoxSample3());
    } //main

    public ListBoxSample3()
    {
        this.set_ClientSize(new Size(292, 181));
        this.set_Text("ListBox Sample3");

        listBox1.set_Location(new Point(24, 16));
        listBox1.set_Name("ListBox1");
        listBox1.set_Size(new Size(232, 130));
        textBox1.set_Location(new Point(24, 160));
        textBox1.set_Name("textBox1");
        textBox1.set_Size(new Size(240, 24));
        this.get_Controls().AddRange(new Control[] { listBox1, textBox1 });

        // Populates the list box using DataSource. 
        // DisplayMember is used to display just the long name of each state.
        ArrayList uSStates = new ArrayList();
        uSStates.Add(new USState("Alabama", "AL"));
        uSStates.Add(new USState("Washington", "WA"));
        uSStates.Add(new USState("West Virginia", "WV"));
        uSStates.Add(new USState("Wisconsin", "WI"));
        uSStates.Add(new USState("Wyoming", "WY"));

        listBox1.add_SelectedValueChanged(
            new EventHandler(listBox1_SelectedValueChanged));
        listBox1.set_DataSource(uSStates);
        listBox1.set_DisplayMember("LongName");
        listBox1.set_ValueMember("ShortName");
    } //ListBoxSample3
    
    private void InitializeComponent()
    {
    } //InitializeComponent

    private void listBox1_SelectedValueChanged(Object sender, EventArgs e)
    {
        if (listBox1.get_SelectedIndex() != -1) {
            textBox1.set_Text(listBox1.get_SelectedValue().ToString());
        }
    } //listBox1_SelectedValueChanged
} //ListBoxSample3 

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0
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