GetEnumerator Method

OrderedDictionary.GetEnumerator Method ()

 

Returns an IDictionaryEnumerator object that iterates through the OrderedDictionary collection.

Namespace:   System.Collections.Specialized
Assembly:  System (in System.dll)

public virtual IDictionaryEnumerator GetEnumerator()

[Visual Basic, C#]

The foreach statement of the C# language (for each in Visual Basic) hides the complexity of the enumerators. Therefore, using foreach is recommended instead of directly manipulating the enumerator.

Enumerators can be used to read the data in the collection, but they cannot be used to modify the underlying collection.

Initially, the enumerator is positioned before the first element in the collection.

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 its behavior is undefined.

The enumerator does not have exclusive access to the collection; therefore, enumerating through a collection is intrinsically not a thread-safe procedure. To guarantee thread safety during enumeration, you can lock the collection during the entire enumeration. To allow the collection to be accessed by multiple threads for reading and writing, you must implement your own synchronization.

This method is an O(1) operation.

The following code example demonstrates the use of the GetEnumerator method to display the contents of the OrderedDictionary collection to the console. In this example, the GetEnumerator method is used to obtain an IDictionaryEnumerator object that is passed to a method that displays the contents. This code is part of a larger code example that can be viewed at OrderedDictionary.

// Clear the OrderedDictionary and add new values
myOrderedDictionary.Clear();
myOrderedDictionary.Add("newKey1", "newValue1");
myOrderedDictionary.Add("newKey2", "newValue2");
myOrderedDictionary.Add("newKey3", "newValue3");

// Display the contents of the "new" Dictionary using an enumerator
IDictionaryEnumerator myEnumerator =
    myOrderedDictionary.GetEnumerator();

Console.WriteLine(
    "{0}Displaying the entries of a \"new\" OrderedDictionary.",
    Environment.NewLine);

DisplayEnumerator(myEnumerator);
// Displays the contents of the OrderedDictionary using its enumerator
public static void DisplayEnumerator(IDictionaryEnumerator myEnumerator)
{
    Console.WriteLine("   KEY                       VALUE");
    while (myEnumerator.MoveNext())
    {
        Console.WriteLine("   {0,-25} {1}",
            myEnumerator.Key, myEnumerator.Value);
    }
}

Universal Windows Platform
Available since 10
.NET Framework
Available since 2.0
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