ToJson

/// <summary>   
    /// DataTable转成Json    
    /// </summary>   
    /// <param name="jsonName"></param>   
    /// <param name="dt"></param>   
    /// <returns></returns>   
    public static string ToJson(DataTable dt, string jsonName)
    {
        StringBuilder Json = new StringBuilder();
        if (string.IsNullOrEmpty(jsonName))
            jsonName = dt.TableName;
        Json.Append("{\"" + jsonName + "\":[");
        if (dt.Rows.Count > 0)
        {
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                Json.Append("{");
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    Type type = dt.Rows[i][j].GetType();
                    Json.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + StringFormat(dt.Rows[i][j].ToString(), type));
                    if (j < dt.Columns.Count - 1)
                    {
                        Json.Append(",");
                    }
                }
                Json.Append("}");
                if (i < dt.Rows.Count - 1)
                {
                    Json.Append(",");
                }
            }
        }
        Json.Append("]}");
        return Json.ToString();
    }

 #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