.netにおけるJsonシーケンス化と逆シーケンス化のクラス

今ではjsonがよく使われるので、シーケンス化や逆シーケンス化が必要になることが多い.,.NET Framewok 3.5はJSONオブジェクトのシーケンス化と逆シーケンス化のクラスも提供する、これがSystemである.Runtime.Serialization.Jsonネーミングスペースの下にあるDataContractJsonSerializerクラス.このクラスによりJSONオブジェクトのシーケンス化と逆シーケンス化が可能となる.
次に、参照用にクラスJSONオブジェクトのシーケンス化と逆シーケンス化のクラスを提供します.
 

/// <summary>
    /// JSON   。        Json      ，   Json         。
    /// </summary>
    public static class JsonHelper
    {
        /// <summary>
        ///       Json    
        /// </summary>
        /// <typeparam name="T">   </typeparam>
        /// <param name="obj">     </param>
        /// <returns>Json   </returns>
        public static string GetJsonFromObj<T>(T obj)
        {
            DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(obj.GetType());
            using (MemoryStream ms = new MemoryStream())
            {
                jsonSerializer.WriteObject(ms, obj);
                return Encoding.UTF8.GetString(ms.ToArray());
            }
        }

        /// <summary>
        ///  Json        
        /// </summary>
        /// <typeparam name="T">    </typeparam>
        /// <param name="strJson">Json   </param>
        /// <returns>         </returns>
        public static T GetObjFromJson<T>(string strJson)
        {
            T obj = Activator.CreateInstance<T>();
            using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(strJson)))
            {
                DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(obj.GetType());
                return (T)jsonSerializer.ReadObject(ms);
            }
        }

        /// <summary>
        ///  DataTable   JSON   
        /// </summary>
        /// <param name="dt">   </param>
        /// <returns>JSON   </returns>
        public static string GetJsonFromDataTable(DataTable dt)
        {
            StringBuilder JsonString = new StringBuilder();
            if (dt != null && dt.Rows.Count > 0)
            {
                JsonString.Append("{ ");
                JsonString.Append("\"TableInfo\":[ ");
                for (int i = 0; i < dt.Rows.Count; i++)
                {
                    JsonString.Append("{ ");
                    for (int j = 0; j < dt.Columns.Count; j++)
                    {
                        if (j < dt.Columns.Count - 1)
                        {
                            JsonString.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + "\"" + dt.Rows[i][j].ToString() + "\",");
                        }
                        else if (j == dt.Columns.Count - 1)
                        {
                            JsonString.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + "\"" + dt.Rows[i][j].ToString() + "\"");
                        }
                    }
                    if (i == dt.Rows.Count - 1)
                    {
                        JsonString.Append("} ");
                    }
                    else
                    {
                        JsonString.Append("}, ");
                    }
                }
                JsonString.Append("]}");
                return JsonString.ToString();
            }
            else
            {
                return null;
            }
        }

        /// <summary> 
        ///       Json    
        /// </summary> 
        /// <param name="obj">   </param> 
        /// <returns>json  </returns> 
        public static string ObjToJson(this object obj)
        {
            JavaScriptSerializer serialize = new JavaScriptSerializer();
            return serialize.Serialize(obj);
        }

        /// <summary> 
        ///  Json        
        /// </summary> 
        /// <param name="strJson">Json   </param> 
        /// <returns>    </returns>
        public static T JsonToObj<T>(string strJson)
        {
            JavaScriptSerializer serialize = new JavaScriptSerializer();
            return serialize.Deserialize<T>(strJson);
        }

        /// <summary> 
        ///       Json   (     )
        /// </summary> 
        /// <param name="obj">   </param> 
        /// <param name="recursionDepth">  </param> 
        /// <returns>json  </returns> 
        public static string ObjToJson(this object obj, int recursionDepth)
        {
            JavaScriptSerializer serialize = new JavaScriptSerializer();
            serialize.RecursionLimit = recursionDepth;
            return serialize.Serialize(obj);
        }

        /// <summary> 
        ///  Json        (     )
        /// </summary> 
        /// <param name="strJson">Json   </param> 
        /// <param name="recursionDepth">  </param> 
        /// <returns>    </returns>
        public static T JsonToObj<T>(string strJson, int recursionDepth)
        {
            JavaScriptSerializer serialize = new JavaScriptSerializer();
            serialize.RecursionLimit = recursionDepth;
            return serialize.Deserialize<T>(strJson);
        }

        /// <summary> 
        ///  DataTable   JSON   
        /// </summary> 
        /// <param name="dt">DataTable</param> 
        /// <returns>json  </returns> 
        public static string DataTableToJson(DataTable dt)
        {
            Dictionary<string, object> dic = new Dictionary<string, object>();

            int index = 0;
            foreach (DataRow dr in dt.Rows)
            {
                Dictionary<string, object> result = new Dictionary<string, object>();

                foreach (DataColumn dc in dt.Columns)
                {
                    result.Add(dc.ColumnName, dr[dc].ToString());
                }
                dic.Add(index.ToString(), result);
                index++;
            }
            return ObjToJson(dic);
        }
    }

呼び出しコードは次のとおりです.

public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            //            
            String strJson = "{\"Name\":\"Test123\",\"Url\":\"http://www.126.com/\"}";
            Person p1 = JsonHelper.GetObjFromJson<Person>(strJson);
            Response.Write("<li>" + p1.Name + " " + p1.Url);
            Person p2 = JsonHelper.JsonToObj<Person>(strJson);
            Response.Write("<li>" + p2.Name + " " + p2.Url);
        }

        protected void Button2_Click(object sender, EventArgs e)
        {
            //       
            String JSONString = string.Empty;
            Person p1 = new Person();
            p1.Name = "Test123'\"
\r\t";
            p1.Url = "http://www.126.com/";
            JSONString = JsonHelper.GetJsonFromObj<Person>(p1);
            Response.Write("<li>" + JSONString);
            JSONString = JsonHelper.ObjToJson(p1);
            Response.Write("<li>" + JSONString);
        }
    }

    /// <summary> 
    ///         DataContractAttribute 
    /// </summary> 
    [DataContractAttribute]
    class Person
    {
        //        DataMember 
        [DataMember]
        public string Name { set; get; }
        [DataMember]
        public string Url { set; get; }
    }