Dictionary<TKey, TValue>.ICollection<KeyValuePair<TKey, TValue>>.IsReadOnly Property
Gets a value indicating whether the dictionary is read-only.
Assembly: mscorlib (in mscorlib.dll)
Property ValueType: System.Boolean
true if the ICollection<T> is read-only; otherwise, false. In the default implementation of Dictionary<TKey, TValue>, this property always returns false.
A collection that is read-only does not allow the addition, removal, or modification of elements after the collection is created.
A collection that is read-only is simply a collection with a wrapper that prevents modifying the collection; therefore, if changes are made to the underlying collection, the read-only collection reflects those changes.
Getting the value of this property is an O(1) operation.