JSON In Code
有关于定义，描述之类的文字官方都有解释：http://json.org/json-zh.html
这次主题主要关于JSON的实际应用
目录
-
JSON in Javascript
-
JSON in Asp.Net
-
LINQ to JSON
-
JSON Serialization
-
XML to JSON
-
Other Resources
1.JSON in Javascript
单列表
<script>
var User = {"UserID":01, "Name":"Rico", "Email":"rico◎hotmail.com"};
alert(User.Name);
</script>
实际应用时，还可以把Name分为FirstName,LastName
{"UserID":01, "Name":{"FirstName":"Rico","LastName":"Rui"}, "Email":"rico◎hotmail.com"}
集合
<script>
var UserList = [
{"UserID":01, "Name":{"FirstName":"Rico","LastName":"Rui"}, "Email":"rico◎hotmail.com"},
{"UserID":02, "Name":{"FirstName":"XXX","LastName":"YYY"}, "Email":"xxx◎hotmail.com"},
{"UserID":03, "Name":{"FirstName":"ZZZ","LastName":"AAA"}, "Email":"YYY◎hotmail.com"}
];
alert(UserList[0].Name.FirstName);
</script>
2.JSON in Asp.Net
Home.aspx: <script language="javascript" type="text/javascript"> $(function() { $.getJSON("../WebForm1.aspx", { t: "json" }, function(o) { alert(o.Name + "->" + o.Rating); } );
//以上写法也可以写成
///$.get("../WebForm1.aspx", {t:"json"}, function(o) { alert(o.Name + "->" + o.Rating); }, "json");
}); </script>
WebForm1.aspx.cs: （这里使用New Page方式,我们也可以使用httphandler方式（webForm1.ashx"））
using System.Web.Script.Serialization;
public partial class WebForm1 :System.Web.UI.Page { protected void Page_Load ( object sender , EventArgs e ) {
JavaScriptSerializer jss = new JavaScriptSerializer (); JSONClass jsonClass = new JSONClass (); jsonClass.Name = "JSON"; jsonClass.Value = 1; Response.ContentType = "text/plain"; Response.Write ( jss.Serialize ( jsonClass ) );
//必须收尾 Response.End ();
}
public class JSONClass {
public string Name;
public int Value;
}
}
3.LINQ to JSON (support in his Json.NET library)
创建数据
private class DataEntity { public string Title { get; set; } public string Description { get; set; } public IList<string> Categories { get; set; } } private List<DataEntity> SetDatas() { return new List<DataEntity>() { new DataEntity() { Title = "Title One", Description = "Description One", Categories = new List<string>() { "Json.NET", "LINQ" } }, new DataEntity() { Title = "Title Two", Description = "Description Two", Categories = new List<string>() { "Json.NET", "CodePlex" } } }; }
public JObject SetDataToJObject(){ List<DataEntity> datas = SetDatas(); JObject rss = new JObject (new JProperty ( "channel" , new JObject (new JProperty ( "title" , "Test Title" ) , new JProperty ( "description" , "Set Data Using JObject" ) , new JProperty ( "item" , new JArray ( from p in datas orderby p.Title select new JObject ( new JProperty ( "title" , p.Title ) , new JProperty ( "description" , p.Description ) , new JProperty ( "category" ,new JArray ( from c in p.Categories select new JValue ( c ) )
)))))));
return rss.ToString ();
}输出的结果
//{ // "channel": { // "title": "Test Title", // "description": "Set Data Using JObject", // "item": [ // { // "title": "Title Two", // "description": "Description Two", // "category": [ // "Json.NET", // "CodePlex" // ] // }, // { // "title": "Title One", // "description": "Description One", // "category": [ // "Json.NET", // "LINQ" // ] // } // ] // } //}
查询数据
public void SearchDataList() {
var dataList = SetDataToJObject();
var titles =
from p in dataList["channel"]["item"]
select p.Value<string> ( "title" );
foreach ( var item in titles ) {
Console.WriteLine ( item );
}
查询结果 //Title One
//Title Two
var categories = from c in dataList["channel"]["item"].Children()["category"].Values<string> () group c by c into g orderby g.Count () descending select new { Category = g.Key , Count = g.Count () }; foreach ( var c in categories ) { Console.WriteLine ( c.Category + " - Count: " + c.Count ); }
查询结果
//Json.NET - Count: 2
//LINQ - Count: 1
//CodePlex - Count: 1
}
*linq to Json 实际上就是linq to object
4.JSON Serialization
有关于序列化：
.NET Framewok 3.5也提供了JSON对象序列化和反序列化的类，System.Runtime.Serialization.Json 命名空间下的 DataContractJsonSerializer 类。
当然也可以使用JSon.Net中的Serializer
以下代码 使用DataContractJsonSerializer 类
定义实体
[DataContract]
public class DataEntity
{
[DataMember]
public String name { get; set; }
[DataMember]
public Int32 value { get; set; }
}
*Json 是在 Windows Communication Foundation (WCF) 中创建的 ASP.NET AJAX 服务所使用的默认数据格式。
所以定义实体会声明相关DataContract,DataMember的属性，
通过将 DataContract 附加到类并将 DataMember 属性附加到要序列化的成员，为DataEntity定义数据协定。
（反）序列化代码
/// <summary> /// JSON序列化 /// </summary> public string JSONSerializer(object item) { DataContractJsonSerializer serializer = new DataContractJsonSerializer(item.GetType()); using (MemoryStream memoryStream = new MemoryStream()) { serializer.WriteObject(memoryStream, item); StringBuilder sb = new StringBuilder(); sb.Append(Encoding.UTF8.GetString(memoryStream.ToArray())); return sb.ToString(); } }
/// <summary> /// JSON 反序列化为对象 /// </summary> public T JSONDeSerializer<T>(string jsonStr) { DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(T)); MemoryStream memoryStream = new MemoryStream(Encoding.UTF8.GetBytes(jsonStr)); T jsonObj = serializer.ReadObject(memoryStream) as T; memoryStream.Close(); return jsonObj; }
序列化工作结束。以下演示如何
使用（反）序列化的数据或对象
获取数据 CODE—> Page
Page:
<script language="javascript" type="text/javascript">
$(function() { $.ajax({ url: "WebForm2.ashx", type: 'GET', data: {}, dataType: 'json', timeout: 1000, error: function(XMLHttpRequest, textStatus, errorThrown) { alert(textStatus) }, success: function(result) { alert(result.name + "->" + result.value); } }); });
</script>
CodeFile:
public class WebForm2: IHttpHandler { public void ProcessRequest(HttpContext context) { DataEntity data = new DataEntity(); data.name = "Name"; data.value = 01; context.Response.Write(data.JSONSerializer()); }
public bool IsReusable { get { return false; } } }
返回结果
{"name":"Name","value":01}
设置数据 Page—>Code
Page:
<script src="json2.js" type="text/javascript"></script>
<script language="javascript" type="text/javascript">
$(function() { var jsData = { name: "Name", value: 01 }; //应用Json2.js中的stringify方法生成JSon String var jsonStr = JSON.stringify(jsData); $.ajax({ url: "WebForm3.ashx", type: 'POST', data: { postjson: jsonStr }, dataType: 'json', timeout: 1000, error: function(XMLHttpRequest, textStatus, errorThrown) { alert(textStatus) }, success: function(result) { alert(result.success); } }); });
</script>
CodeFile:
public class webForm3: IHttpHandler { public void ProcessRequest(HttpContext context) { string jsonStr = context.Request["postjson"]; DataEntity dataEntity = jsonStr.JSONDeSerializer<DataEntity>(); if (string.IsNullOrEmpty(dataEntity.name))
{
context.Response.Write("{success:false}");
}
else
{
context.Response.Write("{success:true}");
}} public bool IsReusable { get { return false; } } }
5.XML to JSON
参考：xml2json
6.其他资源：
1.Enum
首先所有 enum 成员都是可序列化的，然后序列化Enum值时，一般只会生成数字
如：public enum Color {red, green, blue, yellow, pink}，则序列化 yellow 将生成数字 3，而不是字符串“yellow”。2.Time、Date
JSON 格式不直接支持日期和时间,为了解决问题微软也有处理方案，如下
资源参考:
微软ASP.NET AJAX中日期类型的JSON处理
Json 的日期格式与.Net DateTime类型的转换
代码:
Code File: public class Data { public string Name; public DateTime time; } public String getData() { Data pd = new Data ("Rico", DateTime.Now()); return "(" + JavascriptSerializer.Serializer(pd) + ")"; }
Page:
<script language="javascript" type="text/javascript"> var pagedata = eval('<%= getData() %>');
</script>
3.JsonCache
