C#中对象，字符串，dataTable、DataReader、DataSet，对象集合转换成Json字符串方法。

public class ConvertJson
    {
        #region 私有方法
        /// <summary>
        /// 过滤特殊字符
        /// </summary>
        /// <param name="s">字符串</param>
        /// <returns>json字符串</returns>
        private static string String2Json(String s)
        {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < s.Length; i++)
            {
                char c = s.ToCharArray()[i];
                switch (c)
                {
                    case '\"':
                        sb.Append("\\\""); break;
                    case '\\':
                        sb.Append("\\\\"); break;
                    case '/':
                        sb.Append("\\/"); break;
                    case '\b':
                        sb.Append("\\b"); break;
                    case '\f':
                        sb.Append("\\f"); break;
                    case '\n':
                        sb.Append("\\n"); break;
                    case '\r':
                        sb.Append("\\r"); break;
                    case '\t':
                        sb.Append("\\t"); break;
                    default:
                        sb.Append(c); break;
                }
            }
            return sb.ToString();
        }
        /// <summary>
        /// 格式化字符型、日期型、布尔型
        /// </summary>
        /// <param name="str"></param>
        /// <param name="type"></param>
        /// <returns></returns>
        private static string StringFormat(string str, Type type)
        {
            if (type == typeof(string))
            {
                str = String2Json(str);
                str = "\"" + str + "\"";
            }
            else if (type == typeof(DateTime))
            {
                str = "\"" + str + "\"";
            }
            else if (type == typeof(bool))
            {
                str = str.ToLower();
            }
            else if (type != typeof(string) && string.IsNullOrEmpty(str))
            {
                str = "\"" + str + "\"";
            }
            return str;
        }
        #endregion

        #region list转换成JSON
        /// <summary>
        /// list转换为Json
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="list"></param>
        /// <returns></returns>
        public static string ListToJson<T>(IList<T> list)
        {
            object obj = list[0];
            return ListToJson<T>(list, obj.GetType().Name);
        }
        /// <summary>
        /// list转换为json
        /// </summary>
        /// <typeparam name="T1"></typeparam>
        /// <param name="list"></param>
        /// <param name="p"></param>
        /// <returns></returns>
        private static string ListToJson<T>(IList<T> list, string JsonName)
        {
            StringBuilder Json = new StringBuilder();
            if (string.IsNullOrEmpty(JsonName))
                JsonName = list[0].GetType().Name;
            Json.Append("{\"" + JsonName + "\":[");
            if (list.Count > 0)
            {
                for (int i = 0; i < list.Count; i++)
                {
                    T obj = Activator.CreateInstance<T>();
                    PropertyInfo[] pi = obj.GetType().GetProperties();
                    Json.Append("{");
                    for (int j = 0; j < pi.Length; j++)
                    {
                        Type type = pi[j].GetValue(list[i], null).GetType();
                        Json.Append("\"" + pi[j].Name.ToString() + "\":" + StringFormat(pi[j].GetValue(list[i], null).ToString(), type));
                        if (j < pi.Length - 1)
                        {
                            Json.Append(",");
                        }
                    }
                    Json.Append("}");
                    if (i < list.Count - 1)
                    {
                        Json.Append(",");
                    }
                }
            }
            Json.Append("]}");
            return Json.ToString();
        }
        #endregion

        #region 对象转换为Json
        /// <summary>
        /// 对象转换为json
        /// </summary>
        /// <param name="jsonObject">json对象</param>
        /// <returns>json字符串</returns>
        public static string ToJson(object jsonObject)
        {
            string jsonString = "{";
            PropertyInfo[] propertyInfo = jsonObject.GetType().GetProperties();
            for (int i = 0; i < propertyInfo.Length; i++)
            {
                object objectValue = http://www.mamicode.com/propertyInfo[i].GetGetMethod().Invoke(jsonObject, null);>

C#中的DataSet、string、DataTable 、对象转换成Json