Does Dictionary.Keys.List()[i] correspond to Dictionary.Values.ToList()[i]?

I have a Dictionary data type. My开发者_运维百科 question is, is Dictionary.Keys.ToList()[i] always correspond to Dictionary.Values.ToList()[i] ? That is, will the following test always passes

public void DictionaryTest(int i, Dictionary<U,T> dict)
{
  var key = dict.Keys.ToList()[i];
  Assert.AreEqual(dict[key], dict.Values.ToList()[i]); 
}

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I would say yes based on this from MSDN:

The order of the values in the Dictionary.ValueCollection is unspecified, but it is the same order as the associated keys in the Dictionary.KeyCollection returned by the Keys property.

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Checking the MSDN entry for Dictionary.Keys Property:

The order of the keys in the Dictionary.KeyCollection is unspecified, but it is the same order as the associated values in the Dictionary.ValueCollection returned by the Values property.

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Reflector says, that in Framework 2.0 - 4.0 both KeyCollection and ValueCollection are enumerating over dictionary.entries collection. That's why order will be the same. And by the way same order will be for enumerating over dictionary itself (KeyValuePairs).

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In your code - yes. But if you override GetHashCode() into U Class and then made some changes that will change value of GetHashCode() and invoke Assert, it's possible that it will be false, cause Dictionary is implemented as a hash table. The next code returns false:

class Program
    {
        static void Main(string[] args)
        {
            Dictionary<A, int> d = new Dictionary<A, int>();
            for (int i = 1; i <= 10; i++)
            {
                d.Add(new A { Hash = i}, i);
            }
            DictionaryTest(5, d);
        }

        public static void DictionaryTest(int i, Dictionary<A, int> dict)
        {
            A key = dict.Keys.ToList()[i];
            key.Hash = 4;
            Console.WriteLine(dict[key].Equals(dict.Values.ToList()[i]));
            Console.ReadKey();
        }
    }

    public class A
    {
        public int Hash { get; set; }

        public override bool Equals(object obj)
        {
            return this.GetHashCode() == obj.GetHashCode();
        }
        public override int GetHashCode()
        {
            return Hash;
        }
    }