Marks the control and all its children as display only (when displayOnly is true) or
enterable (when displayOnly is false).
Note that a control is considered to be display only if the control or any of its parents
are marked as display only.
This property can be set on all controls but only has meaning where the control or its child controls allow data to be
entered i.e. the control is a FieldControl or a FieldColumnControl.
displayOnlyistrue) or enterable (whendisplayOnlyisfalse). Note that a control is considered to be display only if the control or any of its parents are marked as display only.This property can be set on all controls but only has meaning where the control or its child controls allow data to be entered i.e. the control is a FieldControl or a FieldColumnControl.