check box change event in datagridview using C#

public bool checkedthecheckbox { get; set; }

CheckBox testchbox = new CheckBox();

private void Form1_Load(object sender, EventArgs e)
{
    testchbox.CheckedChanged += new EventHandler(testchbox_CheckedChanged);
}

void testchbox_CheckedChanged(object sender, EventArgs e)
{
    if (testchbox.Checked)
        checkedthecheckbox = true;
    else
        checkedthecheckbox = false;
}