Count of each charecter in a string

//How to count the occurrence of each character in a string

string sentence = "hello world";

Dictionary<char, int> ditCounts = new Dictionary<char, int>();

for (int i = 0; i < sentence.Length; i++)

{

    if (sentence[i] != ' ')

    {

        if (!ditCounts.ContainsKey(sentence[i]))

        {

            ditCounts.Add(sentence[i], 1);

        }

        else

        {

            ditCounts[sentence[i]]++;

        }

    }

}

foreach (var item in ditCounts)

{

    Console.WriteLine(item.Key + " - " + item.Value);

}

Console.ReadKey();