计算字符串中子串出现的次数

// <summary> 

        /// 计算字符串中子串出现的次数

        /// </summary>

        /// <param name="str">字符串</param>

        /// <param name="substring">子串</param>

        /// <returns>出现的次数</returns>

        static int SubstringCount(string str, string substring)

        {

            if (str.Contains(substring))

            {

                string t_sp= str.Replace(substring, "");

                return (str.Length - t_sp.Length) / substring.Length;

            }

            return 0;

        }