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JavaScriptSerializer的使用, 今上午琢磨了半天, 小結一下.

本文轉載自   查看原文   2012-02-21 15:53   12878    工作收獲

需求場景:

 當用戶在頁面上點擊"編輯"按鈕時, 將生成一個自定義對象集合(List<JenkinsTask>), 之后遍歷該集合中的所有任務, 依次啟動Jenkins的構建任務.

同時, aspx頁面上放有一個Ajax的Timer空間, Timer每5秒觸發一次. 每次觸發Timer的時候, 遍歷List<JenkinsTask>集合, 將任務執行結果顯示在頁面的文本框中.

該功能已經由Javascrit實現了, 但是本機調試正常, 客戶機有的正常、有的異常, 而且出錯的情況還各不相同. 於是, 在服務器端, 重新實現一下該功能.

 

問題:

HTTP協議的無狀態特性, 將無法保存List<JenkinsTask>集合, 所以想到序列化該集合並將之保存在ViewState中, C#提供的序列化器有BinaryFormatter、SoapFormatter, 前者以二級制形式序列化對象, 后者以Soap協議格式序列化對象; 還有XML也提供了序列化器. 雖然本次是在服務器段實現該功能, 但考慮到將來可能還會再改到javascript的實現形式, 希望采用Json格式的序列化器.

 

Json格式序列化器有兩種實現System.Runtime.Serialization.Json名空間下的DataContractJsonSerializer類, 和System.Web.Script.Serialization命名空間下的JavaScriptSerializer類, 前者的過程類似於BinaryFormatter的序列化過程, 需要設計IO流等等, 而JavaScriptSerializer類相對就簡單的多, 也不需要添加[Serializable]等Attribute特性字段.

 

實現: (注意: 簡單自定義類 和 復雜自定義類 的操作不同), 解決方案摘取的代碼, 不完整, 還忘見諒.

1. 引用System.Web.Script.Serialization命名空間;

//頁面中的Ajax控件Timer

View Code 
    <asp:Timer ID="timerJenkins" runat="server" ontick="timerJenkins_Tick" Enabled="false" Interval="5000">
    </asp:Timer>
    <asp:UpdatePanel ID="UpdatePanel2" runat="server">
        <Triggers>
            <asp:AsyncPostBackTrigger ControlID="timerJenkins" EventName="Tick" />
        </Triggers>
        <ContentTemplate>
            <table class="infoTable">
                <tr runat="server" id="trAppResult">
                    <td class="infoTital">
                    </td>
                    <td class="infoContent">
                        <div runat="server" id="divBuildResult" style="width: 700px;">
                            &nbsp;
                        </div>
                        <div runat="server" id="divBuildResultStatus" style="width: 700px;">
                        </div>
                    </td>
                </tr>
            </table>
    <div id="divButton">
        <asp:Button ID="btn" runat="server" Text="" OnClientClick="return false;" Width="0"
            Height="0" />
        <asp:Button ID="btnStructure" runat="server" Text="編譯" CssClass="btn_mouseout" onmouseover="this.className='btn_mouseover'"
            onmouseout="this.className='btn_mouseout'" onmousedown="this.className='btn_mousedown'"
            onmouseup="this.className='btn_mouseup'" Style="margin-left: 30px; margin-right: 15px;"
            OnClick="btnStructure_Click" />
        <asp:Button ID="btnSubmit" runat="server" Text="提交" OnCommand="btnSubmit_Click" CssClass="btn_mouseout"
            onmouseover="this.className='btn_mouseover'" onmouseout="this.className='btn_mouseout'"
            onmousedown="this.className='btn_mousedown'" onmouseup="this.className='btn_mouseup'"
            Style="margin-right: 15px;" />
        <asp:Button ID="btnReturn" runat="server" Text="返回" OnClientClick="location.href='DevelopmentApplyList.aspx';return false;"
            CssClass="btn_mouseout" onmouseover="this.className='btn_mouseover'" onmouseout="this.className='btn_mouseout'"
            onmousedown="this.className='btn_mousedown'" onmouseup="this.className='btn_mouseup'" />
    </div>
            </ContentTemplate>
    </asp:UpdatePanel>

 

 

2. 對於簡單的自定義類(類成員多為簡單數據類型), 再點擊按鈕的事件中創建List集合對象, 使用new JavaScriptSerializer().Serialize()即可完成序列化, 在Ajax的Timer控件后台方法中, 使用new JavaScriptSerializer().Deserialize()即可完成反序列化.

實例如下:

//JenkinsTast.cs

View Code 
namespace WebSite.Common
{
    public class JenkinsTask
    {
        private static readonly string JenkinsBaseUrl = ConfigurationManager.AppSettings["JenkinsPath"];
        private static readonly string JenkinsUrlFormat = JenkinsBaseUrl+"/job/{0}";
        private static readonly string JenkinsStartUrlFormat = JenkinsUrlFormat + "/build?delay=0sec";
        private static readonly string JenkinsResponseUrlFormat = JenkinsUrlFormat + "/buildHistory/ajax";
        private static readonly string JenkinsNoticeInfoStart = "構建任務< {0} >已啟動...";
        private static readonly string JenkinsNoticeInfoRun = "構建任務< {0} >正在執行...";

        
　　　　public JenkinsTask()
        { }


        public JenkinsTask(string structureName)
        {
            this.StructureTaskName = structureName;
            this.StructureTaskStatus = Enum.GetName(typeof(JenkinsTaskStatus), JenkinsTaskStatus.Init);
        }

        public string StructureTaskName { get; set; }
        public string StructureTaskStatus { get; set; }
        public int LastStructureId { get; set; }
        public string TarPackageName { get; set; }
        public string OutputHTML { get; set; }
        public string OutputText { get; set; }

        //啟動構建任務
        public void StartJenkinsTask()
        {
            //獲取構建任務ID
            string strId = getLastStructureId(XSSAccessHelper.GetJenkinsResponse(new Uri(string.Format(JenkinsUrlFormat, this.StructureTaskName)), "GET", null));
            int id = 0;
            if (!string.IsNullOrEmpty(strId))
            {
                id = Convert.ToInt32(strId);    
            }
            //啟動構建任務
            XSSAccessHelper.GetJenkinsResponse(new Uri(string.Format(JenkinsStartUrlFormat, this.StructureTaskName)), "GET", null);
            
            //獲取構建任務信息, 將結果填入OutputHTML(Web異步無法啟動, 這里改為只填寫最近一次構建任務的ID)
            //GetStructureResponseInfo(id+1);
            this.LastStructureId = id + 1;

            this.OutputText = string.Format(JenkinsNoticeInfoStart,this.StructureTaskName);
        }

        private string getLastStructureId(string responseHTML)
        {
            string result = "";
            string regId = "<\\s*a\\s*href=\"lastBuild/\">Last\\s+build\\s*\\(#\\d+\\)\\s*,[\\W\\w]+?<\\s*\\/\\s*a\\s*>";
            Regex reg = new Regex(regId,RegexOptions.IgnoreCase);
            if(reg.IsMatch(responseHTML))
            {
                try
                {
                    result = reg.Match(responseHTML).Value;
                    result = result.Substring(result.IndexOf("#")+1, result.IndexOf(")") - result.IndexOf("#")-1);             
                }
                catch
                {
                    throw;
                }
            }
            return result;
        }

        //獲取構建任務信息, 將結果填入OutputHTML
        public void GetStructureResponseInfo()
        {
            this.OutputHTML = XSSAccessHelper.GetJenkinsResponse(new Uri(string.Format(JenkinsResponseUrlFormat, this.StructureTaskName)), "n:" + this.LastStructureId.ToString(), "GET", null);
            this.OutputText = string.Format(JenkinsNoticeInfoRun, this.StructureTaskName);
        }
}

    public enum JenkinsTaskStatus
    {
        Init = 0,
        CompileRunning = 1,
        CompileFinish = 2,
        PackageRunning = 3,
        PackageFinish = 4
    }
}

 

//Test.aspx.cs

View Code 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

using System.Web.Script.Serialization;

namespace WebSite
{
    public partial class TestUCPage_TEST_ : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!this.IsPostBack)
            {
               HttpRequest req = HttpContext.Current.Request;
            }
        }

        protected void btnStructure_Click(object sender, EventArgs e)
        {
            this.btnSubmit.Enabled = false;
            if (this.chkEnvironment.SelectedItem == null)
            {
                this.chkEnvironment.BackColor = System.Drawing.Color.FromName("#FEB8B8");
                return;
            }
            else
            {
                this.chkEnvironment.BackColor = System.Drawing.Color.FromName("#FFFFFF");
            }

            //生成構建任務列表
            if (!string.IsNullOrEmpty(this.hiddenFldStructureList.Value))
            {
                JenkinsTask jt = new JenkinsTask(this.hiddenFldStructureList.Value);
                saveJenkinsTaskList(jt);
　　　　　　　　　　this.timerJenkins.Enabled = true;        
　　　　　　　　}
        }

        protected void timerJenkins_Tick(object sender, EventArgs e)
        {
            JenkinsTask jt = getJenkinsTaskList();
            if (jt != null)
            {
                this.divResult.innerHTML = jt.OutHtml;
            }
　　　　　　　saveJenkinsTaskList(jt); 
        }

        private JenkinsTask getJenkinsTaskList()
        {
            return new JavaScriptSerializer().Deserialize<JenkinsTask>(ViewState["JenkinsTaskList"].ToString());
        }

        private void saveJenkinsTaskList(JenkinsTask jt)
        {
            ViewState["JenkinsTaskList"] = new JavaScriptSerializer().Serialize(jt);
        }

    }
}


這樣就已經可以了, 使用默認的JavaScriptConverter實現時, 必須要一個無參的構造函數.

 

3. 對於復雜的自定義類型(含有自定義類成員, 或沒有無參構造函數, 或私有寫屬性.....等等). 對於復雜類型, 默認的JavaScriptConverter會造成序列化或反序列化無法正常工作, 此時需要自己實現JavaScriptConverter(抽象類), 來完成序列化和反序列過程.

//Jenkins.cs, 類中屬性的Set方法為private, 且沒有默認構造函數

View Code 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

using System.Configuration;
using System.Text.RegularExpressions;
using System.Runtime.Serialization;
using System.Web.Script.Serialization;
//using System.Security.Permissions;

namespace WebSite.Common
{
    public class JenkinsTask
    {
        private static readonly string JenkinsBaseUrl = ConfigurationManager.AppSettings["JenkinsPath"];
        private static readonly string JenkinsUrlFormat = JenkinsBaseUrl+"/job/{0}";
        private static readonly string JenkinsStartUrlFormat = JenkinsUrlFormat + "/build?delay=0sec";
        private static readonly string JenkinsResponseUrlFormat = JenkinsUrlFormat + "/buildHistory/ajax";
        private static readonly string JenkinsNoticeInfoStart = "構建任務< {0} >已啟動...";
        private static readonly string JenkinsNoticeInfoRun = "構建任務< {0} >正在執行...";

        public JenkinsTask(string structureName)
        {
            this.StructureTaskName = structureName;
            this.StructureTaskStatus = Enum.GetName(typeof(JenkinsTaskStatus), JenkinsTaskStatus.Init);
        }

        public JenkinsTask(string structureName, JenkinsTaskStatus structureStatus, int structureId, string outHtml, string outText)
        {
            this.StructureTaskName = structureName;
            this.StructureTaskStatus = Enum.GetName(typeof(JenkinsTaskStatus),structureStatus);
            this.LastStructureId = structureId;
            this.OutputHTML = outHtml;
            this.OutputText = outText;
        }

        public string StructureTaskName { get; private set; }
        public string StructureTaskStatus { get; private set; }
        public int LastStructureId { get; private set; }
        public string TarPackageName { get; private set; }
        public string OutputHTML { get; private set; }
        public string OutputText { get; private set; }

        //啟動構建任務
        public void StartJenkinsTask()
        {
            //獲取構建任務ID
            string strId = getLastStructureId(XSSAccessHelper.GetJenkinsResponse(new Uri(string.Format(JenkinsUrlFormat, this.StructureTaskName)), "GET", null));
            int id = 0;
            if (!string.IsNullOrEmpty(strId))
            {
                id = Convert.ToInt32(strId);    
            }
            //啟動構建任務
            XSSAccessHelper.GetJenkinsResponse(new Uri(string.Format(JenkinsStartUrlFormat, this.StructureTaskName)), "GET", null);
            
            //獲取構建任務信息, 將結果填入OutputHTML(Web異步無法啟動, 這里改為只填寫最近一次構建任務的ID)
            //GetStructureResponseInfo(id+1);
            this.LastStructureId = id + 1;

            this.OutputText = string.Format(JenkinsNoticeInfoStart,this.StructureTaskName);
        }

        private string getLastStructureId(string responseHTML)
        {
            string result = "";
            string regId = "<\\s*a\\s*href=\"lastBuild/\">Last\\s+build\\s*\\(#\\d+\\)\\s*,[\\W\\w]+?<\\s*\\/\\s*a\\s*>";
            Regex reg = new Regex(regId,RegexOptions.IgnoreCase);
            if(reg.IsMatch(responseHTML))
            {
                try
                {
                    result = reg.Match(responseHTML).Value;
                    result = result.Substring(result.IndexOf("#")+1, result.IndexOf(")") - result.IndexOf("#")-1);             
                }
                catch
                {
                    throw;
                }
            }
            return result;
        }

        //獲取構建任務信息, 將結果填入OutputHTML
        public void GetStructureResponseInfo()
        {
            this.OutputHTML = XSSAccessHelper.GetJenkinsResponse(new Uri(string.Format(JenkinsResponseUrlFormat, this.StructureTaskName)), "n:" + this.LastStructureId.ToString(), "GET", null);
            this.OutputText = string.Format(JenkinsNoticeInfoRun, this.StructureTaskName);
        }
 }

    public enum JenkinsTaskStatus
    {
        Init = 0,
        CompileRunning = 1,
        CompileFinish = 2,
        PackageRunning = 3,
        PackageFinish = 4
    }

    /// <summary>
    /// 單個Jenkins任務的序列化和反序列化
    /// </summary>
    public class JenkinsTaskConverter : JavaScriptConverter
    {
        public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
        {
            IDictionary<string, object> dict = new Dictionary<string, object>();
            if (obj != null)
            {
                JenkinsTask jt = obj as JenkinsTask;
                dict["StructureTaskName"] = jt.StructureTaskName;
                dict["StructureTaskStatus"] = jt.StructureTaskStatus;
                dict["LastStructureId"] = jt.LastStructureId;
                dict["OutputHTML"] = jt.OutputHTML;
                dict["OutputText"] = jt.OutputText;
            }
            return dict;
        }

        public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
        {
            return new JenkinsTask(Convert.ToString(dictionary["StructureTaskName"]), (JenkinsTaskStatus)Enum.Parse(typeof(JenkinsTaskStatus), Convert.ToString(dictionary["StructureTaskStatus"])), Convert.ToInt32(dictionary["LastStructureId"]), Convert.ToString(dictionary["OutputHTML"]), Convert.ToString(dictionary["OutputText"]));
        }

        public override IEnumerable<Type> SupportedTypes
        {
            get 
            { 
                yield return typeof(JenkinsTask); 
            }
        }
    }

    /// <summary>
    /// Jenkins任務集合的序列化和反序列化, 測試代碼, 此處只提供個針對 序列化復雜類集合 的思路...
    /// </summary>
    //public class JenkinsTaskListConverter : JavaScriptConverter
    //{
    //    public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
    //    {
    //        IDictionary<string, object> dict = new Dictionary<string, object>();
    //        if (obj != null)
    //        {
    //            List<JenkinsTask> jtLst = obj as List<JenkinsTask>;
    //            if (jtLst != null && jtLst.Count > 0)
    //            {
    //                dict["JenkinsTaskCollection"] = jtLst;
    //            }
   //           //dict["ItemCount"] = jtLst.Count;
   //         }
   //         return dict;
   //     }

   //     public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
   //     {
   //         return dictionary["JenkinsTaskCollection"] as List<JenkinsTask>;
   //     }

   //     public override IEnumerable<Type> SupportedTypes
   //     {
   //         get { yield return typeof(List<JenkinsTask>); }
   //    }
   // }
}

 

 //Test.aspx.cs, 注意在Page_Load時候注冊了自定義的JavaScriptConverter轉換器

View Code 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

using System.Web.Script.Serialization;

namespace WebSite
{
    public partial class TestUCPage_TEST_ : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

　　　　　　　　JavaScriptSerializer jss = new JavaScriptSerializer();

　　　　　　　//注冊JenkinsTask轉換器
            　jss.RegisterConverters(new JenkinsTaskConverter[] { new JenkinsTaskConverter() });

            if (!this.IsPostBack)
            {
               HttpRequest req = HttpContext.Current.Request;
            }
        }

        protected void btnStructure_Click(object sender, EventArgs e)
        {
            this.btnSubmit.Enabled = false;
            if (this.chkEnvironment.SelectedItem == null)
            {
                this.chkEnvironment.BackColor = System.Drawing.Color.FromName("#FEB8B8");
                return;
            }
            else
            {
                this.chkEnvironment.BackColor = System.Drawing.Color.FromName("#FFFFFF");
            }

            //生成構建任務列表
            if (!string.IsNullOrEmpty(this.hiddenFldStructureList.Value))
            {
                JenkinsTask jt = new JenkinsTask(this.hiddenFldStructureList.Value);
                saveJenkinsTaskList(jt);
 　　　　　　　　　　this.timerJenkins.Enabled = true;
            }
        }

        protected void timerJenkins_Tick(object sender, EventArgs e)
        {
　　　　　　　　this.timerJenkins.Enabled = false;
            JenkinsTask jt = getJenkinsTaskList();
            if (jt != null)
            {
                this.divResult.innerHTML = jt.OutHtml;
            }
　　　　　　　　saveJenkinsTaskList(jt);
　　　　　　　　this.timerJenkins.Enabled = true;
        }

        private JenkinsTask getJenkinsTaskList()
        {

            return jss.Deserialize<JenkinsTask>(ViewState["JenkinsTaskList"].ToString());
        }

        private void saveJenkinsTaskList(JenkinsTask jt)
        {

            ViewState["JenkinsTaskList"] = jss.Serialize(jt);
        }

    }
}

 

 總結:

額外的, 在Javascript中, 是可以讀取隱藏域中的  序列化后的內容的, 這樣的就能在JS中用eval("("+strSerialize+")")獲得JSon對象.

對於今天上午遇到的場景, 其實用 列1中, 所描述的"簡單類型"的情形, 就能解決問題. 之所以, 引出后邊的東東, 是因為開始時候JenkinsTask任務中, 沒有寫默認構造函數, 其中的幾個屬性也是Set訪問器也是private的, 所以一直無法反序列化成功. 雖然犯了回低級錯誤, 但是對這幾個序列化器的內容梳理的一邊, 標記下也算沒白費功夫.

 

//服務端跨站訪問Jenkins的代碼, 服務端實現的訪問Jenkis的代碼, 與本貼主題無關, 標記一下

View Code 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

using System.Text.RegularExpressions;
using System.Configuration;
using System.Net;
using System.IO;
using System.Text;

namespace WebSite.Common
{
    public class XSSAccessHelper
    {
        private static readonly string jenkinsUrl = ConfigurationManager.AppSettings["JenkinsPath"];
        private static readonly string jenkinsName = ConfigurationManager.AppSettings["JenkinsName"];
        private static readonly string jenkinsPwd = ConfigurationManager.AppSettings["JenkinsPwd"];

        public static string GetJenkinsResponse(Uri url, string requestType, string postRequestBody)
        {
            return GetJenkinsResponse(url, null, requestType, postRequestBody);
        }

        /// <summary>
        /// 從Jenkins上獲取返回值信息
        /// </summary>
        /// <param name="url">請求的Jenkins地址</param>
        /// <param name="requestHeader">自定義的請求頭, 每個請求頭為以":"分隔的名值對, 多個名值對之間以","分隔</param>
        /// <param name="requestType">請求頭類型("GET" or "POST")</param>
        /// <param name="postRequestBody">POST類型的請求包體, 可為NULL或空字符串</param>
        /// <returns>從Jenkins上返回的HTML信息(已去除回車換行)</returns>
        public static string GetJenkinsResponse(Uri url,string requestHeader,string requestType, string postRequestBody)
        {
            string responseHTML = "";
            #region SetRequest
            HttpWebRequest hwRequest = getJenkinsRequest(url);
            hwRequest.Method = requestType;
            if (!string.IsNullOrEmpty(requestHeader))
            {
                foreach (string str in requestHeader.Split(','))
                {
                    if (!string.IsNullOrEmpty(str))
                        hwRequest.Headers.Add(str);
                }
            }
            if(requestType == "POST")
            {
                //異步請求必須添加ContentType請求頭
                hwRequest.ContentType = "application/x-www-form-urlencoded";
                //請求包體
                if (!string.IsNullOrEmpty(postRequestBody))
                {
                    byte[] postBodyBytes = Encoding.Default.GetBytes(postRequestBody);//傳遞的值
                    hwRequest.ContentLength = postBodyBytes.Length;
                    //把傳遞的值寫到流中
                    using (Stream requestStream = hwRequest.GetRequestStream())
                    {
                        try
                        {
                            requestStream.Write(postBodyBytes, 0, postBodyBytes.Length);
                        }
                        catch (Exception ex)
                        {
                            throw ex;
                        }
                    }
                }
            }
            #endregion

            #region GetResponse
            using (HttpWebResponse hwrResponse = hwRequest.GetResponse() as HttpWebResponse)
            using (Stream responseStream = hwrResponse.GetResponseStream())
            using (StreamReader sReader = new StreamReader(responseStream, Encoding.UTF8))
            {
                try
                {
                    responseHTML = formatHtml(sReader.ReadToEnd());
                }
                catch (Exception ex)
                {
                    throw ex;
                }
            }
            return responseHTML;
            #endregion
        }


        private static HttpWebRequest getJenkinsRequest(Uri requestUrl)
        {
            CredentialCache cCache = new CredentialCache();
            cCache.Add(new Uri(jenkinsUrl), "Basic", new NetworkCredential(jenkinsName, jenkinsPwd));
            return (HttpWebRequest)WebRequestHelper.GetRequest(requestUrl, cCache);
        }

        private static string formatHtml(string responseHTML)
        {
            return responseHTML.Replace("\r\n", "").Replace("\n", "");
        }
    }

public class WebRequestHelper
    {
        public static WebRequest GetRequest(Uri requestUrl, CredentialCache credential)
        {
            HttpWebRequest request = null;
            if (requestUrl != null)
            {
                try
                {
                    request = HttpWebRequest.Create(requestUrl) as HttpWebRequest;
                    if (credential != null)
                    {
                        request.Credentials = credential;
                        NetworkCredential nCredential = CredentialCache.DefaultNetworkCredentials;
                        request.Headers["Authorization"] = "Basic" + Convert.ToBase64String(Encoding.Default.GetBytes(nCredential.UserName + ":" + nCredential.Password));
                    }
                }
                catch
                {
                    throw;
                }
            }
            return request;
        }
    }
}

 

補充:

JavaScriptSerializer序列化和反序列化JSON：使用自定義JavaScriptConverter
JSON的序列化和反序列化已經成為Web開發必不可少的知識。現在常用的有System.Web.Script.Serialization下的JavaScriptSerializer來進行處理；另外一個比較常用且高效的類庫是JSON.NET。

在開發一些小的應用時，由於想盡量較少項目的依賴，所以不太願意使用JSON.NET。JavaScriptSerializer基本上能滿足簡單的需求，但當一個屬性要序列化成別的名字時，就顯得力不從心了。還有就是可能業務需要，某些屬性不希望在某一個條件下進行序列化。鑒於上面的業務需要，我們就需要自定義一個JavaScriptConverter。

自定義JavaScriptConverter的使用流程：

定義一個JavaScriptConverter，指明期支持的類型。
在序列化方法調用前注冊該轉換器。
顯然，這兩個步驟都不是很麻煩。我們舉一個具體的業務環境來說明：在ExtJS的TreePanel控件中，TreeNode的屬性有id、text等，其中如果checked屬性存在，則屬性結果顯示節點選擇框。在C#中，checked是關鍵字，所以不能定義為屬性，TreeNode的C#代碼如下：

復制代碼
    public class TreeNode
    {
        public string id { get; set; }
        public string text { get; set; }
        public bool? isChecked { get; set; }
        public List<TreeNode> children { get; set; }
    }
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我將checked屬性映射到類中的isChecked字段，該字段可以有三個狀態：null、true和false，當為null的時候，將不會序列化該字段，前台也不會顯示節點選擇框。

現在要實現一個TreeNodeJSConverter，代碼如下：

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    public class TreeNodeJSConverter : JavaScriptConverter
    {
        public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
        {
            TreeNode node = new TreeNode();

            object value = null;
            if (dictionary.TryGetValue("id", out value))
                node.id = (string)value;
            if (dictionary.TryGetValue("text", out value))
                node.text = (string)value;
            if (dictionary.TryGetValue("children", out value))
            {
                if (value != null && value.GetType() == typeof(ArrayList))
                {
                    var list = (ArrayList)value;
                    node.children = new List<TreeNode>();

                    foreach (Dictionary<string, object> item in list)
                    {
                        node.children.Add((TreeNode)this.Deserialize(item, type, serializer));
                    }
                }
                else
                {
                    node.children = null;
                }
            }
            return node;
        }

        public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
        {
            Dictionary<string, object> dic = new Dictionary<string, object>();
            var node = obj as TreeNode;
            if (node == null)
                return null;
            if(!string.IsNullOrEmpty(node.id))
            dic.Add("id", node.id);
            if (!string.IsNullOrEmpty(node.text))
            dic.Add("text", node.text);
            if (node.isChecked.HasValue)
                dic.Add("checked", node.isChecked.Value);
            if (node.children != null)
            dic.Add("children", node.children);

            return dic;
        }

        public override IEnumerable<Type> SupportedTypes
        {
            get
            {
                return new Type[] { typeof(TreeNode) };
            }
        }
    }
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代碼討論：TreeNodeJSConverter類首先需要繼承JavaScriptConverter，然后實現它的相關方法：Deserialize、Serialize和SupportedTypes，分別是反序列化、序列化和支持的類型。

在序列化方法Serialize中，我們需要將屬性添加到一個字典結構中，就可以完成序列化的工作了。具體要序列化那些字段還是要判斷一下相應的值是否存在。

在反序列化方法Deserialize中，字典結構存放着相應的值，當值存在的時候就可以為TreeNode相應的字段賦值。比較麻煩的事children屬性，因為其為嵌套的List類型，而JSON中的數組結構會被轉化成ArrayList結構，所以我們只需要遞歸的循環ArrayList中的每一個項，將其轉換為TreeNode就可以了。

最后是SupportedTypes字段，返回支持的類型，我們這里顯示的返回TreeNode的類型。

 

定義好了轉換器之后，我們需要為在序列化的時候注冊該轉換器即可：

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        public static string SerializeToJson(object obj)
        {
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            serializer.RegisterConverters(new JavaScriptConverter[] { new TreeNodeJSConverter() });

            return serializer.Serialize(obj);
        }

        public static T DeserializeJson<T>(string jsonString)
        {
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            serializer.RegisterConverters(new JavaScriptConverter[] { new TreeNodeJSConverter() });

            return serializer.Deserialize<T>(jsonString);
        }
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代碼中標紅的部分就是注冊轉化器的地方，用起來很方便，代碼都貼出來了，不再提供源碼下載了。。親，早點睡吧！
View Code

 

 

 

 

 

 折騰着一上午, 已經用掉很多時間了, 這里就草草標記一下, 不再整理了. 其中參考了3篇文章, 深受啟發.

 

我已經把三篇放一起了, 文章地址: http://www.cnblogs.com/cs_net/articles/2361181.html

三篇原帖地址:

http://heeroluo.net/ShowPost15.aspx

http://www.cnblogs.com/Henllyee/archive/2008/07/18/1246161.html

http://www.cnblogs.com/zhuisha/archive/2008/12/08/1350463.html

 


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