StringEnumerator::MoveNext Method ()
Advances the enumerator to the next element of the collection.
Assembly: System (in System.dll)
Return Value
Type: System::Booleantrue if the enumerator was successfully advanced to the next element; false if the enumerator has passed the end of the collection.
| Exception | Condition |
|---|---|
| InvalidOperationException | The collection was modified after the enumerator was created. |
After an enumerator is created or after a Reset is called, an enumerator is positioned before the first element of the collection, and the first call to MoveNext moves the enumerator over the first element of the collection.
If MoveNext passes the end of the collection, the enumerator is positioned after the last element in the collection and MoveNext returns false. When the enumerator is at this position, subsequent calls to MoveNext also return false until Reset is called.
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 MoveNext and Current, Current returns the element that it is set to, even if the enumerator is already invalidated.
The following code example demonstrates several of the properties and methods of StringEnumerator.
#using <System.dll> using namespace System; using namespace System::Collections::Specialized; int main() { // Creates and initializes a StringCollection. StringCollection^ myCol = gcnew StringCollection; array<String^>^myArr = {"red","orange","yellow","green","blue","indigo","violet"}; myCol->AddRange( myArr ); // Enumerates the elements in the StringCollection. StringEnumerator^ myEnumerator = myCol->GetEnumerator(); while ( myEnumerator->MoveNext() ) Console::WriteLine( "{0}", myEnumerator->Current ); Console::WriteLine(); // Resets the enumerator and displays the first element again. myEnumerator->Reset(); if ( myEnumerator->MoveNext() ) Console::WriteLine( "The first element is {0}.", myEnumerator->Current ); } /* This code produces the following output. red orange yellow green blue indigo violet The first element is red. */
Available since 10
.NET Framework
Available since 1.1