checkbox list check only limited items - asp.net

Question

I have a list of check boxes and I want to have an upper limit for you many you can check.
Here is what i have done.
int numSelected = 0;
foreach (ListItem li in chkMultiBrand.Items)
{
if (li.Selected)
{
numSelected = numSelected + 1;
}
}
for (int i = 0; i < chkMultiBrand.Items.Count; i++)
{
if (numSelected >= Convert.ToInt32(objLimit.UPPERLIMIT))
{
chkMultiBrand.Items[i].Selected = false;
}
}

Answer 1

I assume if the max number has been exceeded you want to uncheck the last box that was checked so this should work
public void chk_SelectedIndexChanged(object sender, EventArgs e)
{
int numSelected = 0;
foreach (ListItem li in chkMultiBrand.Items)
{
if (li.Selected)
{
numSelected = numSelected + 1;
}
}
if (numSelected >= Convert.ToInt32(objLimit.UPPERLIMIT))
{
string[] control = Request.Form.Get("__EVENTTARGET").Split('$');
int index = control.Length - 1;
ListItem lastChecked = (ListItem) chkMultiBrand.Items[Int32.Parse(control[index])];
lastChecked.Selected = false;
}
}
Although I would possibly try to do this client side if possible - something like this http://jsfiddle.net/CXfgS/2/

Answer 2

If Im reading this correctly as your code stands what yours doing is
Counting the number of checked boxes in the whole list
If the number from the prvious count is greater than the max allowed set everything to false
You need to combine the loops - this isn't perfect as it doesn't track the order in which the items are selected so only the first X number of checkboxes will remain checked and any subsequent items will be unselected.
int numSelected = 0;
foreach (ListItem li in chkMultiBrand.Items)
{
if (numSelected >= Convert.ToInt32(objLimit.UPPERLIMIT))
{
li.Selected = false;
}
if (li.Selected)
{
numSelected = numSelected + 1;
}
}