Dictionary<TKey,TValue>.KeyCollection.Enumerator.IEnumerator.Reset Method

Definition

Sets the enumerator to its initial position, which is before the first element in the collection.

C#
void IEnumerator.Reset();

Implements

Exceptions

The collection was modified after the enumerator was created.

Remarks

After calling the IEnumerator.Reset method, 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.

An enumerator remains valid as long as the collection remains unchanged. If changes are made to the collection, such as adding elements or changing the capacity, the enumerator is irrecoverably invalidated and the next call to MoveNext or IEnumerator.Reset throws an InvalidOperationException.

.NET Core 3.0+ only: The only mutating methods which do not invalidate enumerators are Remove and Clear.

Applies to

Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1
UWP 10.0

See also