Microsoft Docs

Overview

The DictionaryBase class provides a base implementation for a strongly typed dictionary that maps keys to values. It simplifies the creation of custom dictionary classes by handling much of the standard dictionary functionality.

Syntax

public abstract class DictionaryBase : IDictionary, ICollection, IEnumerable

Inherits from Object. Implements the following interfaces:

  • IDictionary
  • ICollection
  • IEnumerable

Examples

C#
VB.NET
using System;
using System.Collections;

public class MyDictionary : DictionaryBase
{
    public void Add(string key, string value) => Dictionary.Add(key, value);
    public string this[string key]
    {
        get => (string)Dictionary[key];
        set => Dictionary[key] = value;
    }
    public void Remove(string key) => Dictionary.Remove(key);
    public ICollection Keys => Dictionary.Keys;
    public ICollection Values => Dictionary.Values;
}

class Program
{
    static void Main()
    {
        var dict = new MyDictionary();
        dict.Add("One", "1");
        dict.Add("Two", "2");
        Console.WriteLine(dict["One"]);
    }
}

Imports System
Imports System.Collections

Public Class MyDictionary
    Inherits DictionaryBase

    Public Sub Add(key As String, value As String)
        Dictionary.Add(key, value)
    End Sub

    Default Public Property Item(key As String) As String
        Get
            Return DirectCast(Dictionary(key), String)
        End Get
        Set(value As String)
            Dictionary(key) = value
        End Set
    End Property

    Public Sub Remove(key As String)
        Dictionary.Remove(key)
    End Sub

    Public ReadOnly Property Keys As ICollection
        Get
            Return Dictionary.Keys
        End Get
    End Property

    Public ReadOnly Property Values As ICollection
        Get
            Return Dictionary.Values
        End Get
    End Property
End Class

Module Module1
    Sub Main()
        Dim dict As New MyDictionary()
        dict.Add("One", "1")
        dict.Add("Two", "2")
        Console.WriteLine(dict("One"))
    End Sub
End Module

Remarks

When inheriting from DictionaryBase, you must provide the implementation for the required members as shown in the examples. The base class handles synchronization, enumeration, and collection semantics.

See Also