How to set up event for when any combobox value changes

I was hoping someone can help me figure out a good way to loop through all the Comboboxes in my configurator and add the same event to it (rather than having to set up each individual OnFieldChanged event).

I tried this in the UI OnLoaded event:

foreach(var control in Inputs.cbBackup.Control.Parent.Controls

control.OnValueChanged+=(e)=>{};//this gives an error saying I don’t have permission (this is a protected method)

Is there anything similar to this I can do? or even make an OnMouseDown event for the panel?