Net 3.5 用DataContractJsonSerializer实现Json序列和反序列例子

近来在研究jQuery,用$.ajax在与后台交换数据时用到Json格式,后台与前台序列化和反序列化方法研究了很久才成功,发文共享.

前台调用的JS文件需要用到jQuery-1.2.6.js和json2.js,后台引用空间System.Runtime.Serialization和System.Runtime.Serialization.Json

Json序列化和反序列化方法

        /// <summary>
        /// Json序列化,用于发送到客户端
        /// </summary>
        public static string ToJsJson(this object item)
        {

            DataContractJsonSerializer serializer = new DataContractJsonSerializer(item.GetType());

            using (MemoryStream ms = new MemoryStream())
            {

                serializer.WriteObject(ms, item);

                StringBuilder sb = new StringBuilder();

                sb.Append(Encoding.UTF8.GetString(ms.ToArray()));

                return sb.ToString();

            }

        }

        /// <summary>
        /// Json反序列化,用于接收客户端Json后生成对应的对象
        /// </summary>
        public static T FromJsonTo<T>(this string jsonString)
        {

            DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T));

            MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(jsonString));

            T jsonObject = (T)ser.ReadObject(ms);

            ms.Close();

            return jsonObject;

        }

实体类

    [DataContract]
    public class TestObj
    {
        [DataMember]
        public string make { get; set; }
        [DataMember]
        public string model { get; set; }
        [DataMember]
        public int year { get; set; }
        [DataMember]
        public string color { get; set; }
    }

--------------------------------------------javascript获取Json---------------------------------

javascript调用测试代码

$('#getJson').click(function() {
                $.ajax({
                    url: "getJsonHandler.ashx",
                    type: 'GET',
                    data: {},
                    dataType: 'json',
                    timeout: 1000,
                    error: function(XMLHttpRequest, textStatus, errorThrown) { alert(textStatus) },
                    success: function(result) {

                        alert(result.make);
                        alert(result.model);
                        alert(result.year);
                        alert(result.color);
                    }

                });
            });

C#后台生成代码

public class getJsonHandler: IHttpHandler
    {
public void ProcessRequest(HttpContext context)
        {
            TestObj obj = new TestObj();

            obj.make = "Make is Value";
            obj.model = "Model is Value";
            obj.year = 999;
            obj.color = "Color is Value";

            context.Response.Write(obj.ToJsJson());
        }
 public bool IsReusable
        {
            get
            {
                return false;
            }
        }
}

//返回值为 {"color":"Color is Value","make":"Make is Value","model":"Model is Value","year":999}

 

---------------------------------C#由Json生成对象---------------------------------------

javascript调用测试代码

           $('#postJson').click(function() {

                var m_obj = { make: "Dodge", model: "Coronet R/T", year: 1968, color: "yellow" };
                var jsonStr = JSON.stringify(m_obj); //用Json2.js生成Json字符串

                $.ajax({
                    url: "postJsonHandler.ashx",
                    type: 'POST',
                    data: { postjson: jsonStr },
                    dataType: 'json',
                    timeout: 1000,
                    error: function(XMLHttpRequest, textStatus, errorThrown) { alert(textStatus) },
                    success: function(result) {

                        alert(result.success);
                    }

                });
});

C#后台生成代码

public class postJsonHandler: IHttpHandler
    {
        public void ProcessRequest(HttpContext context)
        {
            string jsonStr = context.Request["postjson"];

            TestObj obj = jsonStr.FromJsonTo<TestObj>();

            if (string.IsNullOrEmpty(obj.make) || string.IsNullOrEmpty(obj.model) || string.IsNullOrEmpty(obj.color) 

|| obj.year < 0)
            {
                context.Response.Write("{success:false}");
            }
            else
            {
                context.Response.Write("{success:true}");
            }

public bool IsReusable
        {
            get
            {
                return false;
            }
        }
}

使用Json时需要注意,服务器端拼凑生成Json字符串时,一定要注意把字符串用\"\"包裹,不然客户端接收时肯定会报错,根据Json字符串生成对象,是根据对应的名称赋值,多于或少于都不会报错.