定义新的Dictionary成员方法C＃

Question

I want to define a new member method for Dictionary as it already built in member methods eg Add() , Clear() , ContainsKey() etc.

That newly added member method should return all the keyvaluepairs in form of a Set as we can return map.entrySet() to Set in Java.

Can existing methods for dictionary be overridden to achieve this ?

Answer 1

You could create an extension method:

using System;
using System.Collections.Generic;
using System.Linq;

public static class DictionaryExtensions {
    public static HashSet<KeyValuePair<TKey, TValue>> ToSet<TKey, TValue>(this Dictionary<TKey, TValue> dict) {
        return new HashSet<KeyValuePair<TKey, TValue>>(dict.ToList());
    }
} 

Info about extension methods: https://msdn.microsoft.com/en-us/library/bb383977(v=vs.110).aspx

Answer 2

I'm aware it's not a set, but by using Linq you can get a list of key value pairs like so:

Dictionary<string, string> dictionary = new Dictionary<string, string>();
List<KeyValuePair<string, string>> keyValuePairs = dictionary.ToList();

Answer 3

Just in case it helps, you can access KeyValue pair of the Dictionary like this :

// Example dictionary
var dic = new Dictionary<int, string>{{1, "a"}};

foreach (var item in dic)
{
    Console.WriteLine(string.Format("key : {0}, Value : {1}", item.Key, item.Value));
}