Gets a value indicating whether the collection is read-only.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
A read-only collection does not allow the addition, removal, or modification of elements after the collection is created.
A read-only collection is simply a collection with a wrapper that prevents modifying the collection. If changes are made to the underlying collection, the read-only collection reflects those changes.
Available since 2.0