Assembly: mscorlib (in mscorlib.dll)
Thetype exposes the following members.
|Equals(Object)||Determines whether the specified object is equal to the current object. (Inherited from Object.)|
|GetHashCode||Serves as the default hash function. (Inherited from Object.)|
|GetType||Gets the Type of the current instance. (Inherited from Object.)|
|MoveNext||Moves to the next element in the collection.|
|Reset||Resets the enumerator to the beginning of the collection.|
|ToString||Returns a string that represents the current object. (Inherited from Object.)|
Enumerators allow only reading the data in the collection. Enumerators cannot be used to modify the underlying collection.
Initially, the enumerator is positioned before the first element in the collection. The Reset method also brings the enumerator back to this position. At this position, calling the Current property throws an exception. Therefore, you must call the MoveNext method to advance the enumerator to the first element of the collection before reading the value of the Current property.
After the end of the collection is passed, the enumerator is positioned after the last element in the collection, and calling MoveNext returns false. If the last call to MoveNext returned false, calling Current throws an exception. To reset Current to the first element of the collection, call Reset followed by a call to MoveNext.
An enumerator remains valid as long as the collection remains unchanged. If changes are made to the collection, such as adding, modifying, or deleting elements, the enumerator is irrecoverably invalidated and the next call to MoveNext or Reset throws an InvalidOperationException. If the collection is modified between calling MoveNext and Current, Current returns the element to which it is currently set, even if the enumerator is already invalidated.
The enumerator does not have exclusive access to the collection; therefore, enumerating through a collection is intrinsically not a thread-safe procedure. Even when a collection is synchronized, other threads can still modify the collection, which causes the enumerator to throw an exception. To guarantee thread safety during enumeration, you can either lock the collection during the entire enumeration or catch the exceptions resulting from changes made by other threads.