Only one checkbox to be selected

Question

I would like to only have single checkbox selected at a time. My program reads from a textfile and creates checkboxes according to how many \"answers\" there are in the text

Answer 1

It's so simple to achieve what you want, however it's also so strange:

//We need this to hold the last checked CheckBox
CheckBox lastChecked;
private void chk_Click(object sender, EventArgs e) {
   CheckBox activeCheckBox = sender as CheckBox;
   if(activeCheckBox != lastChecked && lastChecked!=null) lastChecked.Checked = false;
   lastChecked = activeCheckBox.Checked ? activeCheckBox : null;
}