The following code example demonstrates the creation, population and modification of an OrderedDictionary collection, as well as two techniques to display the contents of the OrderedDictionary: one using the Keys and Values properties and the other creating an enumerator through the GetEnumerator method.
' The following code example enumerates the elements of a OrderedDictionary.
Imports System
Imports System.Collections
Imports System.Collections.Specialized
Public Class OrderedDictionarySample
Public Shared Sub Main()
' Creates and initializes a OrderedDictionary.
Dim myOrderedDictionary As New OrderedDictionary()
myOrderedDictionary.Add("testKey1", "testValue1")
myOrderedDictionary.Add("testKey2", "testValue2")
myOrderedDictionary.Add("keyToDelete", "valueToDelete")
myOrderedDictionary.Add("testKey3", "testValue3")
Dim keyCollection As ICollection = myOrderedDictionary.Keys
Dim valueCollection As ICollection = myOrderedDictionary.Values
' Display the contents Imports the key and value collections
DisplayContents( _
keyCollection, valueCollection, myOrderedDictionary.Count)
' Modifying the OrderedDictionary
If Not myOrderedDictionary.IsReadOnly Then
' Insert a new key to the beginning of the OrderedDictionary
myOrderedDictionary.Insert(0, "insertedKey1", "insertedValue1")
' Modify the value of the entry with the key "testKey2"
myOrderedDictionary("testKey2") = "modifiedValue"
' Remove the last entry from the OrderedDictionary: "testKey3"
myOrderedDictionary.RemoveAt(myOrderedDictionary.Count - 1)
' Remove the "keyToDelete" entry, if it exists
If (myOrderedDictionary.Contains("keyToDelete")) Then
myOrderedDictionary.Remove("keyToDelete")
End If
End If
Console.WriteLine( _
"{0}Displaying the entries of a modified OrderedDictionary.", _
Environment.NewLine)
DisplayContents( _
keyCollection, valueCollection, myOrderedDictionary.Count)
' 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 Imports an enumerator
Dim myEnumerator As IDictionaryEnumerator = _
myOrderedDictionary.GetEnumerator()
Console.WriteLine( _
"{0}Displaying the entries of a 'new' OrderedDictionary.", _
Environment.NewLine)
DisplayEnumerator(myEnumerator)
Console.ReadLine()
End Sub
' Displays the contents of the OrderedDictionary from its keys and values
Public Shared Sub DisplayContents( _
ByVal keyCollection As ICollection, _
ByVal valueCollection As ICollection, ByVal dictionarySize As Integer)
Dim myKeys(dictionarySize) As [String]
Dim myValues(dictionarySize) As [String]
keyCollection.CopyTo(myKeys, 0)
valueCollection.CopyTo(myValues, 0)
' Displays the contents of the OrderedDictionary
Console.WriteLine(" INDEX KEY VALUE")
Dim i As Integer
For i = 0 To dictionarySize - 1
Console.WriteLine(" {0,-5} {1,-25} {2}", _
i, myKeys(i), myValues(i))
Next i
Console.WriteLine()
End Sub
' Displays the contents of the OrderedDictionary using its enumerator
Public Shared Sub DisplayEnumerator( _
ByVal myEnumerator As IDictionaryEnumerator)
Console.WriteLine(" KEY VALUE")
While myEnumerator.MoveNext()
Console.WriteLine(" {0,-25} {1}", _
myEnumerator.Key, myEnumerator.Value)
End While
End Sub
End Class
'This code produces the following output.
'
' INDEX KEY VALUE
'0: testKey1(testValue1)
'1: testKey2(testValue2)
'2: keyToDelete(valueToDelete)
'3: testKey3(testValue3)
'
'
'Displaying the entries of a modified OrderedDictionary.
' INDEX KEY VALUE
'0: insertedKey1(insertedValue1)
'1: testKey1(testValue1)
'2: testKey2(modifiedValue)
'
'
'Displaying the entries of a "new" OrderedDictionary.
' KEY(VALUE)
' newKey1(newValue1)
' newKey2(newValue2)
' newKey3(newValue3)
// The following code example enumerates the elements of a OrderedDictionary.
using System;
using System.Collections;
using System.Collections.Specialized;
public class OrderedDictionarySample
{
public static void Main()
{
// Creates and initializes a OrderedDictionary.
OrderedDictionary myOrderedDictionary = new OrderedDictionary();
myOrderedDictionary.Add("testKey1", "testValue1");
myOrderedDictionary.Add("testKey2", "testValue2");
myOrderedDictionary.Add("keyToDelete", "valueToDelete");
myOrderedDictionary.Add("testKey3", "testValue3");
ICollection keyCollection = myOrderedDictionary.Keys;
ICollection valueCollection = myOrderedDictionary.Values;
// Display the contents using the key and value collections
DisplayContents(keyCollection, valueCollection, myOrderedDictionary.Count);
// Modifying the OrderedDictionary
if (!myOrderedDictionary.IsReadOnly)
{
// Insert a new key to the beginning of the OrderedDictionary
myOrderedDictionary.Insert(0, "insertedKey1", "insertedValue1");
// Modify the value of the entry with the key "testKey2"
myOrderedDictionary["testKey2"] = "modifiedValue";
// Remove the last entry from the OrderedDictionary: "testKey3"
myOrderedDictionary.RemoveAt(myOrderedDictionary.Count - 1);
// Remove the "keyToDelete" entry, if it exists
if (myOrderedDictionary.Contains("keyToDelete"))
{
myOrderedDictionary.Remove("keyToDelete");
}
}
Console.WriteLine(
"{0}Displaying the entries of a modified OrderedDictionary.",
Environment.NewLine);
DisplayContents(keyCollection, valueCollection, myOrderedDictionary.Count);
// 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);
Console.ReadLine();
}
// Displays the contents of the OrderedDictionary from its keys and values
public static void DisplayContents(
ICollection keyCollection, ICollection valueCollection, int dictionarySize)
{
String[] myKeys = new String[dictionarySize];
String[] myValues = new String[dictionarySize];
keyCollection.CopyTo(myKeys, 0);
valueCollection.CopyTo(myValues, 0);
// Displays the contents of the OrderedDictionary
Console.WriteLine(" INDEX KEY VALUE");
for (int i = 0; i < dictionarySize; i++)
{
Console.WriteLine(" {0,-5} {1,-25} {2}",
i, myKeys[i], myValues[i]);
}
Console.WriteLine();
}
// 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);
}
}
}
/*
This code produces the following output.
INDEX KEY VALUE
0 testKey1 testValue1
1 testKey2 testValue2
2 keyToDelete valueToDelete
3 testKey3 testValue3
Displaying the entries of a modified OrderedDictionary.
INDEX KEY VALUE
0 insertedKey1 insertedValue1
1 testKey1 testValue1
2 testKey2 modifiedValue
Displaying the entries of a "new" OrderedDictionary.
KEY VALUE
newKey1 newValue1
newKey2 newValue2
newKey3 newValue3
*/