Question

I have a CheckedListBox which contains many items which can be checked or unchecked individually.

Next to this are CheckBoxes representing supersets of the many items opposite. These are tri-state corresponding to what portion of their items are selected opposite.

Both the CheckedListBox and individual CheckBoxes subscribe to check changed type events which is causing a circular reference and overflow. How can I disable one from receiving change events when the other is updating it, programmatically?

Answer 1

void checkBox1_N_CheckStateChanged(object sender, EventArgs e) {
    checkedListBox1.ItemCheck -= this.CheckedListBox1_ItemCheck;
    // Handler body where affecting CheckedListBox1.
    checkedListBox1.ItemCheck += this.CheckedListBox1_ItemCheck;
}

It works best to disable each others’ event handlers as the other is updating.

void CheckedListBox1_ItemCheck(object sender, EventArgs e) {
    //Find which 'i' is affected.
    arrOfCBox[i].cb.CheckStateChanged -= arrOfCBox[i].eh;
    // Handler body where affecting checkBox[i].
    arrOfCBox[i].cb.CheckStateChanged += arrOfCBox[i].eh;
}

where BoxHandler is, at a minimum:

    class BoxHandler
    {
        public EventHandler eh;
        public CheckBox cb;
    }

Similar to WinForms: temporarily disable an event handler, but amazingly that didn’t get awarded an answer, (prolly too abstract?).