How to use AutoCheck property of CheckBox in C#?

Last Updated : 30 Sep, 2021

The CheckBox control is the part of the windows form that is used to take input from the user. Or in other words, CheckBox control allows us to select single or multiple elements from the given list. You are allowed to set a value that determines the Checked or CheckedStates values and also the appearance of the CheckBox is set automatically when you click a CheckBox using the AutoCheck property. The value of this property is of System.Boolean type.
If the value of AutoCheck property is true, then the value of Checked or CheckState and the appearance of the CheckBox is changed automatically when you click a CheckBox. Otherwise, false. The default value of this property is true. In Windows form, you can set this property in two different ways:

1. Design-Time: It is the simplest way to set the AutoCheck property of a CheckBox using the following steps:

Step 1: Create a windows form as shown in the below image
Visual Studio -> File -> New -> Project -> WindowsFormApp

Step 2: Drag the CheckBox control from the ToolBox and drop it on the windows form. You can place CheckBox anywhere on the windows form according to your need.

Step 3: After drag and drop you will go to the properties of the CheckBox control to set the value of the AutoCheck property.

Output:

2. Run-Time: It is a little bit trickier than the above method. In this method, you can set the AutoCheck property of a CheckBox programmatically using the following syntax:

public bool AutoCheck { get; set; }

Following steps are used to set the AutoCheck property of the CheckBox:

Step 1: Create a checkbox using the CheckBox() constructor provided by the CheckBox class.

// Creating checkbox
CheckBox Mycheckbox = new CheckBox();

Step 2: After creating CheckBox, set the AutoCheck property of the CheckBox provided by the CheckBox class.

// Set the AutoCheck property of the CheckBox
Mycheckbox.AutoCheck = false;

Step 3: And last add this checkbox control to form using Add() method.

// Add this checkbox to form
this.Controls.Add(Mycheckbox);

Example:

C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
 
namespace WindowsFormsApp5 {
 
public partial class Form1 : Form {
 
    public Form1()
    {
        InitializeComponent();
    }
 
    private void Form1_Load(object sender, EventArgs e)
    {
        // Creating and setting the properties of label
        Label l = new Label();
        l.Text = "Select language:";
        l.AutoSize = true;
        l.Location = new Point(233, 111);
        l.Font = new Font("Bradley Hand ITC", 12);
        // Adding label to form
        this.Controls.Add(l);
 
        // Creating and setting the properties of CheckBox
        CheckBox Mycheckbox = new CheckBox();
        Mycheckbox.Height = 50;
        Mycheckbox.Width = 100;
        Mycheckbox.Location = new Point(229, 136);
        Mycheckbox.Text = "C#";
        Mycheckbox.AutoCheck = false;
        Mycheckbox.Font = new Font("Bradley Hand ITC", 12);
 
        // Adding checkbox to form
        this.Controls.Add(Mycheckbox);
 
        // Creating and setting the properties of CheckBox
        CheckBox Mycheckbox1 = new CheckBox();
        Mycheckbox1.Height = 50;
        Mycheckbox1.Width = 100;
        Mycheckbox1.Location = new Point(230, 198);
        Mycheckbox1.Text = "Ruby";
        Mycheckbox1.AutoCheck = true;
        Mycheckbox1.Font = new Font("Bradley Hand ITC", 12);
 
        // Adding checkbox to form
        this.Controls.Add(Mycheckbox1);
    }
}
}