how to count checked rows in a repeater

int count =0;
foreach (RepeaterItem item in YourRepeater.Items)
{
    if (item.ItemType == ListItemType.Item || item.ItemType == ListItemType.AlternatingItem)
    {
        var checkBox = (CheckBox)item.FindControl("checkboxName");
        if(checkBox.Checked)
            count++;
    }
}