Question

I have two CheckBoxLists and I need to be able to set the ListItems selected in one of the CheckBoxList depending on the items selected in the other CheckBoxList.

How can I know which ListItem inside a CheckBoxList had issued the postback? The method must be run at server.

SOLUTION UPDATE:

Final solution i used (thanks to Four):

protected void CheckBoxList1_SelectedIndexChanged(object sender, EventArgs e)
{
    var selectedItem = CheckBoxList1.SelectedItem;
}

Where selectedItem is the ListItem that was clicked.

Answer 1

Much simpler:

var selectedItem = CheckBoxList1.SelectedItem;