Get Status(Checked /UnChecked ) of the current Checkbox In CheckBoxList on the SelectedIndexChangeProperty()

I used the following sample code to try to get it done:

Markup :

<asp:CheckBoxList ID="CheckBoxList1" AutoPostBack="true" runat="server"
       onselectedindexchanged="CheckBoxList1_SelectedIndexChanged">
   </asp:CheckBoxList>

CodeBehind:

protected void Page_Load(object sender, EventArgs e)
{
        if (!IsPostBack)
        {
            ListItem item1 = new ListItem("1", "1");
            ListItem item2 = new ListItem("2", "2");
            ListItem item3 = new ListItem("3", "3");

            CheckBoxList1.Items.Add(item1);
            CheckBoxList1.Items.Add(item2);
            CheckBoxList1.Items.Add(item3);
        }
    }
 
    protected void CheckBoxList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (CheckBoxList1.SelectedItem != null)
        {
            if (CheckBoxList1.SelectedItem.Selected)
                Response.Write("You checked " + CheckBoxList1.SelectedItem.Text);
            else
                Response.Write("You unchecked " + CheckBoxList1.SelectedItem.Text);
        }
}

The SelectedIndexChanged event is fired in both cases (Check box check and uncheck) and, Asp.net can give you the correct selected item in the CheckBoxList when you "check" one (I found one case however it was failing to show the correct check box). But, unfortunately, when you "uncheck" a check box, it can't give you the information because the "CheckBoxList1.SelectedItem" is null and there is no other suitable property to get this information.

So, you have to do some client side scripting (Using JQuery or JavaScripts) to get the checked or unchecked check box reference, store or send this information to codebehind and then execute the server side code with that information.