Control.EnabledChanged Event

Reference

Definition

Namespace:: System.Windows.Forms

Assembly:: System.Windows.Forms.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Occurs when the Enabled property value has changed.

public:
 event EventHandler ^ EnabledChanged;

public event EventHandler EnabledChanged;

public event EventHandler? EnabledChanged;

member this.EnabledChanged : EventHandler

Public Custom Event EnabledChanged As EventHandler

Event Type

EventHandler

Examples

The following code example uses two RadioButton controls to demonstrate the EnabledChanged event. Clicking one button changes the value of the Enabled property of the other button to false and displays a MessageBox.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

public class Form1 : Form
{
    private RadioButton radioButton1;
    private RadioButton radioButton2;

    public Form1()
    {
        InitializeComponent();
    }
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Form1());
    }

    private void InitializeComponent()
    {
        this.radioButton1 = new System.Windows.Forms.RadioButton();
        this.radioButton2 = new System.Windows.Forms.RadioButton();
        this.SuspendLayout();
        // 
        // radioButton1
        // 
        this.radioButton1.AutoSize = true;
        this.radioButton1.Location = new System.Drawing.Point(0, 0);
        this.radioButton1.Name = "radioButton1";
        this.radioButton1.Size = new System.Drawing.Size(62, 17);
        this.radioButton1.TabIndex = 0;
        this.radioButton1.TabStop = true;
        this.radioButton1.Text = "Button1";
        this.radioButton1.UseVisualStyleBackColor = true;
        this.radioButton1.EnabledChanged += new System.EventHandler(this.radioButton1_EnabledChanged);
        // 
        // radioButton2
        // 
        this.radioButton2.AutoSize = true;
        this.radioButton2.Location = new System.Drawing.Point(0, 39);
        this.radioButton2.Name = "radioButton2";
        this.radioButton2.Size = new System.Drawing.Size(100, 17);
        this.radioButton2.TabIndex = 1;
        this.radioButton2.TabStop = true;
        this.radioButton2.Text = "Disable Button1";
        this.radioButton2.UseVisualStyleBackColor = true;
        this.radioButton2.CheckedChanged += new System.EventHandler(this.radioButton2_CheckedChanged);
        // 
        // Form1
        // 
        this.ClientSize = new System.Drawing.Size(292, 273);
        this.Controls.Add(this.radioButton2);
        this.Controls.Add(this.radioButton1);
        this.Name = "Form1";
        this.ResumeLayout(false);
        this.PerformLayout();
    }

    private void radioButton2_CheckedChanged(object sender, EventArgs e)
    {
        radioButton1.Enabled = false;
    }

    private void radioButton1_EnabledChanged(object sender, EventArgs e)
    {
        MessageBox.Show("This button has been disabled.");
    }
}

Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Text
Imports System.Windows.Forms



Public Class Form1
   Inherits Form
   Private WithEvents radioButton1 As RadioButton
   Private WithEvents radioButton2 As RadioButton
   
   
   Public Sub New()
      InitializeComponent()
   End Sub
   
   <STAThread()>  _
   Shared Sub Main()
      Application.EnableVisualStyles()
      Application.SetCompatibleTextRenderingDefault(False)
      Application.Run(New Form1())
   End Sub
   
   
   Private Sub InitializeComponent()
      Me.radioButton1 = New System.Windows.Forms.RadioButton()
      Me.radioButton2 = New System.Windows.Forms.RadioButton()
      Me.SuspendLayout()
      ' 
      ' radioButton1
      ' 
      Me.radioButton1.AutoSize = True
      Me.radioButton1.Location = New System.Drawing.Point(0, 0)
      Me.radioButton1.Name = "radioButton1"
      Me.radioButton1.Size = New System.Drawing.Size(62, 17)
      Me.radioButton1.TabIndex = 0
      Me.radioButton1.TabStop = True
      Me.radioButton1.Text = "Button1"
      Me.radioButton1.UseVisualStyleBackColor = True
      ' 
      ' radioButton2
      ' 
      Me.radioButton2.AutoSize = True
      Me.radioButton2.Location = New System.Drawing.Point(0, 39)
      Me.radioButton2.Name = "radioButton2"
      Me.radioButton2.Size = New System.Drawing.Size(100, 17)
      Me.radioButton2.TabIndex = 1
      Me.radioButton2.TabStop = True
      Me.radioButton2.Text = "Disable Button1"
      Me.radioButton2.UseVisualStyleBackColor = True
      ' 
      ' Form1
      ' 
      Me.ClientSize = New System.Drawing.Size(292, 273)
      Me.Controls.Add(radioButton2)
      Me.Controls.Add(radioButton1)
      Me.Name = "Form1"
      Me.ResumeLayout(False)
      Me.PerformLayout()
   End Sub
    
   
   Private Sub radioButton2_CheckedChanged(sender As Object, e As EventArgs) Handles radioButton2.CheckedChanged
      radioButton1.Enabled = False
   End Sub
   
   
   Private Sub radioButton1_EnabledChanged(sender As Object, e As EventArgs) Handles radioButton1.EnabledChanged
      MessageBox.Show("This button has been disabled.")
   End Sub
End Class

Remarks

This event is raised if the Enabled property is changed by either a programmatic modification or user interaction.

For more information about handling events, see Handling and Raising Events.

Applies to

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