C# Dictionary 用法 -- 查找字符串中同一个字符出现次数

 string str ="welcome to bejing , hello china，jiyou wuhan";
 Dictionary<char, int> dict = new Dictionary<char, int>();

            for (int i = 0; i < str.Length; i++)
            {
                if (str[i] == ' ')
                {
                    continue;
                }

                if (dict.ContainsKey(str[i]))
                {
                    dict[str[i]]++;
                }
                else
                {
                    dict[str[i]] = 1;
                }

            }

            foreach (KeyValuePair<char,int> k in dict)
            {
                Console.WriteLine("字符:{0} 共出现{1}次",k.Key,k.Value);

            }

            Console.ReadKey();

运行结果: