c#读XML数据时提示错误：未将对象引用设置到对象的实例。

liguokun 2012-07-24 10:59:41

代码如下：





 private void GetProList()

    {

        //掌柜鑫名品，查看其宝贝列表，我无意冒犯掌柜鑫名品

        #region 绑定到GridView1

        CreatTable();

        myapi = new taobaoApi();

        XmlDocument mydoc = myapi.taobao_items_get("", "iid,title,nick,type,cid,pic_path,delist_time,price,post_fee", 0, 0, "鑫名品");

        XmlNodeList mylist = mydoc.SelectNodes("rsp/item");



        

        int num = int.Parse(mydoc.SelectSingleNode("/rsp/totalResults").InnerText);

        

        try

        {

            AddXmlNodesToTable(mylist);



            //this.Label1.Text = "共有 " + num.ToString() + " 商品";

            this.GridView1.DataSource = dt;

            this.GridView1.DataBind();

        }

        catch (Exception err)

        {

            string test = err.Message;

        }

        #endregion



        #region 返回string值，主要是根据string内容，生成xmlnodelist



        //myapi = new taobaoApi();

        //string mydoc = myapi.taobao_items_get2("", "iid,title,nick,type,cid,pic_path,delist_time,price,post_fee", 0, 0, "鑫名品");

        //divMeg.InnerText = mydoc;

        #endregion





    }

其中执行到这一句 int num = int.Parse(mydoc.SelectSingleNode("/rsp/totalResults").InnerText);
，提示如下错误：

“/TaoBaoAPITest”应用程序中的服务器错误。
--------------------------------------------------------------------------------

未将对象引用设置到对象的实例。
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。

源错误:

行 92:
行 93:
行 94: int num = int.Parse(mydoc.SelectSingleNode("/rsp/totalResults").InnerText);
行 95:
行 96: try

源文件: c:\Documents and Settings\stu\桌面\TaoBaoAPITest\TaoBaoAPITest\productlist.aspx.cs 行: 94

堆栈跟踪:

[NullReferenceException: 未将对象引用设置到对象的实例。]
productlist.GetProList() in c:\Documents and Settings\stu\桌面\TaoBaoAPITest\TaoBaoAPITest\productlist.aspx.cs:94
productlist.Page_Load(Object sender, EventArgs e) in c:\Documents and Settings\stu\桌面\TaoBaoAPITest\TaoBaoAPITest\productlist.aspx.cs:31
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +15
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +33
System.Web.UI.Control.OnLoad(EventArgs e) +99
System.Web.UI.Control.LoadRecursive() +47
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1436

请问是什么原因哦？

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liguokun 2012-07-24

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[Quote=引用 2 楼的回复:]
贴你的mydoc.OuterXml代码
[/Quote]

taobaoApi的代码如下：





//using System;

//using System.Collections.Generic;

//using System.Text;

//using System.Web;

//using System.Xml;



using System;

using System.Collections;

using System.Collections.Generic;

using System.Text;

using System.Net;

using System.IO;

using System.Security.Cryptography;

using System.Xml;

using System.Xml.Linq;

using System.Web;





  

   public class taobaoApi

    {

        public const string VERSION = "1.0";



        private string _sessionID;



        #region 构造函数

        public taobaoApi()

        {

        }

        public taobaoApi(string sessionID)

        {

            _sessionID = sessionID;

        }

        #endregion



        #region 属性

       //获取session

        public  string SessionID

        {

            get

            {

                if (string.IsNullOrEmpty(HttpContext.Current.Session["sip_sessionid"].ToString()))

                {

                    HttpContext.Current.Session["sip_sessionid"] = Guid.NewGuid().ToString();

                }

                return HttpContext.Current.Session["sip_sessionid"].ToString();

            }

        }



        #endregion



        #region 商品接口









       /// <summary>

       /// 获取某会员商品列表达式

       /// </summary>

       /// <param name="q"></param>

       /// <param name="fields"></param>

       /// <param name="page_no"></param>

       /// <param name="page_size"></param>

       /// <param name="nicks"></param>

       /// <returns></returns>

        public XmlDocument taobao_items_get(string q, string fields, int page_no, int page_size, string nicks)

        {

    

            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.items.get");



            pb.AddParam("fields", fields);//"iid,delist_time"

            pb.AddParam("v", VERSION);

            if (q != string.Empty) 

                     pb.AddParam("q", q);

            if(page_no != 0)

             pb.AddParam("page_no", page_no);

            if(page_size != 0)

                 pb.AddParam("page_size", page_size);

            // / 

           pb.AddParam("nicks", nicks);

            //if(order_by != "")

            //    pb.AddParam("order_by", order_by);

            string data = pb.GetURL();



            return Util.HttpRequest(data);

        }



       /// <summary>

       /// 获取宝贝列表的返回值

       /// </summary>

       /// <param name="q"></param>

       /// <param name="fields"></param>

       /// <param name="page_no"></param>

       /// <param name="page_size"></param>

       /// <param name="nicks"></param>

       /// <returns></returns>

        public string taobao_items_get2(string q, string fields, int page_no, int page_size, string nicks)

        {



            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.items.get");



            pb.AddParam("fields", fields);//"iid,delist_time"

            pb.AddParam("v", VERSION);

            if (q != string.Empty)

                pb.AddParam("q", q);

            if (page_no != 0)

                pb.AddParam("page_no", page_no);

            if (page_size != 0)

                pb.AddParam("page_size", page_size);

            // / 

            pb.AddParam("nicks", nicks);

            //if(order_by != "")

            //    pb.AddParam("order_by", order_by);

            string data = pb.GetURL();



            return Util.HttpRequest2(data);

        }



  





       /// <summary>

        ///获取当前会话用户（必须为卖家）的出售中商品列表。支持分页。

       /// </summary>

        /// <param name="q">搜索字段</param>

        /// <param name="fields">商品对象字段</param>

        /// <param name="page_no">页码</param>

        /// <param name="page_size">页显示数量</param>

        /// <param name="has_discount">是否参与会员折扣</param>

        /// <param name="has_showcase">是否橱窗推荐</param>

       /// <returns></returns>

        public HttpWebResponse taobao_items_onsale_get(string q, string fields, int page_no, int page_size, bool has_discount, bool has_showcase,string orderby, string cid, string seller_cids)

        {



            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.items.onsale.get");



            pb.AddParam("fields", fields);//"iid,delist_time"

            pb.AddParam("v", VERSION);

            if (q != string.Empty)

                pb.AddParam("q", q);

            if (page_no != 0)

                pb.AddParam("page_no", page_no);

            if (page_size != 0)

                pb.AddParam("page_size", page_size);

            if (has_discount)

            {

                pb.AddParam("has_discount", "true");

            }

            if (has_showcase)

            {

                pb.AddParam("has_showcase", "true");

            }

            if (orderby.Length != 0)

                pb.AddParam("order_by", orderby);

            if (cid.Length != 0)

                pb.AddParam("cid", cid);

            if (seller_cids.Length != 0)

                pb.AddParam("seller_cids", seller_cids);

            //pb.AddParam("sip_usertoken", token);

            string data = pb.GetURL();

            return Util.HttpRequest3(data);

        }

       

      





  

      



        #endregion



        #region 用户接口

       

        #endregion



        #region 店铺接口

        /// <summary>

        /// 

        /// </summary>

      

        /// <param name="fields"></param>

        /// <param name="nicks"></param>

        /// <returns></returns>

        public XmlDocument taobao_shop_get(string fields, string nicks)

        {



            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.shop.get");



            pb.AddParam("fields", fields);//nick,sex,buyer_credit,seller_credit,location.city,created,real_name,shop_id

            pb.AddParam("v", VERSION);

            pb.AddParam("nick", nicks);



            string data = pb.GetURL();



            return Util.HttpRequest(data);

        }





       //taobao.shop.update

        public XmlDocument taobao_shop_update(string _title, string _bulletin, string _desc)

        {

            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.shop.update");



            pb.AddParam("title", _title);//nick,sex,buyer_credit,seller_credit,location.city,created,real_name,shop_id

            pb.AddParam("v", VERSION);

            pb.AddParam("bulletin", _bulletin);

            pb.AddParam("desc", _desc);

            string data = pb.GetURL();



            return Util.HttpRequest(data);

        }

        #endregion 



     



        #region 类目属性接口





      

       //taobao.itemcats.get.v2 ok

       /// <summary>

        /// 获取后台供卖家发布商品的标准商品类目(获取品牌型号)



       /// </summary>

       /// <param name="parent_cid"></param>

       /// <param name="cids"></param>

       /// <param name="fields"></param>

       /// <returns></returns>

        public HttpWebResponse taobao_itemcats_get_v2(string parent_cid, string cids, string fields)

        {

            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.itemcats.get.v2");



            if (parent_cid.Length != 0 || cids.Length != 0)

            {

                if (parent_cid != "")

                {

                    pb.AddParam("parent_cid", parent_cid);//



                }

                if (cids != "")

                {

                    pb.AddParam("cids", cids);//



                }

            }

            pb.AddParam("fields", fields);

            pb.AddParam("v", VERSION);

            string data = pb.GetURL();



            return Util.HttpRequest3(data);

        }



      

        #endregion





    }

liguokun 2012-07-24

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在吗？

liguokun 2012-07-24

打赏
举报

[Quote=引用 2 楼的回复:]
贴你的mydoc.OuterXml代码
[/Quote]

taobaoApi的代码如下：







using System;

using System.Collections;

using System.Collections.Generic;

using System.Text;

using System.Net;

using System.IO;

using System.Security.Cryptography;

using System.Xml;

using System.Xml.Linq;

using System.Web;





  

   public class taobaoApi

    {

        public const string VERSION = "1.0";



        private string _sessionID;



        #region 构造函数

        public taobaoApi()

        {

        }

        public taobaoApi(string sessionID)

        {

            _sessionID = sessionID;

        }

        #endregion



        #region 属性

       //获取session

        public  string SessionID

        {

            get

            {

                if (string.IsNullOrEmpty(HttpContext.Current.Session["sip_sessionid"].ToString()))

                {

                    HttpContext.Current.Session["sip_sessionid"] = Guid.NewGuid().ToString();

                }

                return HttpContext.Current.Session["sip_sessionid"].ToString();

            }

        }



        #endregion



        #region 商品接口









       /// <summary>

       /// 获取某会员商品列表达式

       /// </summary>

       /// <param name="q"></param>

       /// <param name="fields"></param>

       /// <param name="page_no"></param>

       /// <param name="page_size"></param>

       /// <param name="nicks"></param>

       /// <returns></returns>

        public XmlDocument taobao_items_get(string q, string fields, int page_no, int page_size, string nicks)

        {

    

            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.items.get");



            pb.AddParam("fields", fields);//"iid,delist_time"

            pb.AddParam("v", VERSION);

            if (q != string.Empty) 

                     pb.AddParam("q", q);

            if(page_no != 0)

             pb.AddParam("page_no", page_no);

            if(page_size != 0)

                 pb.AddParam("page_size", page_size);

            // / 

           pb.AddParam("nicks", nicks);

            //if(order_by != "")

            //    pb.AddParam("order_by", order_by);

            string data = pb.GetURL();



            return Util.HttpRequest(data);

        }



       /// <summary>

       /// 获取宝贝列表的返回值

       /// </summary>

       /// <param name="q"></param>

       /// <param name="fields"></param>

       /// <param name="page_no"></param>

       /// <param name="page_size"></param>

       /// <param name="nicks"></param>

       /// <returns></returns>

        public string taobao_items_get2(string q, string fields, int page_no, int page_size, string nicks)

        {



            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.items.get");



            pb.AddParam("fields", fields);//"iid,delist_time"

            pb.AddParam("v", VERSION);

            if (q != string.Empty)

                pb.AddParam("q", q);

            if (page_no != 0)

                pb.AddParam("page_no", page_no);

            if (page_size != 0)

                pb.AddParam("page_size", page_size);

            // / 

            pb.AddParam("nicks", nicks);

            //if(order_by != "")

            //    pb.AddParam("order_by", order_by);

            string data = pb.GetURL();



            return Util.HttpRequest2(data);

        }



  





       /// <summary>

        ///获取当前会话用户（必须为卖家）的出售中商品列表。支持分页。

       /// </summary>

        /// <param name="q">搜索字段</param>

        /// <param name="fields">商品对象字段</param>

        /// <param name="page_no">页码</param>

        /// <param name="page_size">页显示数量</param>

        /// <param name="has_discount">是否参与会员折扣</param>

        /// <param name="has_showcase">是否橱窗推荐</param>

       /// <returns></returns>

        public HttpWebResponse taobao_items_onsale_get(string q, string fields, int page_no, int page_size, bool has_discount, bool has_showcase,string orderby, string cid, string seller_cids)

        {



            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.items.onsale.get");



            pb.AddParam("fields", fields);//"iid,delist_time"

            pb.AddParam("v", VERSION);

            if (q != string.Empty)

                pb.AddParam("q", q);

            if (page_no != 0)

                pb.AddParam("page_no", page_no);

            if (page_size != 0)

                pb.AddParam("page_size", page_size);

            if (has_discount)

            {

                pb.AddParam("has_discount", "true");

            }

            if (has_showcase)

            {

                pb.AddParam("has_showcase", "true");

            }

            if (orderby.Length != 0)

                pb.AddParam("order_by", orderby);

            if (cid.Length != 0)

                pb.AddParam("cid", cid);

            if (seller_cids.Length != 0)

                pb.AddParam("seller_cids", seller_cids);

            //pb.AddParam("sip_usertoken", token);

            string data = pb.GetURL();

            return Util.HttpRequest3(data);

        }

       

      





  

      



        #endregion



        #region 用户接口

       

        #endregion



        #region 店铺接口

        /// <summary>

        /// 

        /// </summary>

      

        /// <param name="fields"></param>

        /// <param name="nicks"></param>

        /// <returns></returns>

        public XmlDocument taobao_shop_get(string fields, string nicks)

        {



            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.shop.get");



            pb.AddParam("fields", fields);//nick,sex,buyer_credit,seller_credit,location.city,created,real_name,shop_id

            pb.AddParam("v", VERSION);

            pb.AddParam("nick", nicks);



            string data = pb.GetURL();



            return Util.HttpRequest(data);

        }





       //taobao.shop.update

        public XmlDocument taobao_shop_update(string _title, string _bulletin, string _desc)

        {

            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.shop.update");



            pb.AddParam("title", _title);//nick,sex,buyer_credit,seller_credit,location.city,created,real_name,shop_id

            pb.AddParam("v", VERSION);

            pb.AddParam("bulletin", _bulletin);

            pb.AddParam("desc", _desc);

            string data = pb.GetURL();



            return Util.HttpRequest(data);

        }

        #endregion 



     



        #region 类目属性接口





      

       //taobao.itemcats.get.v2 ok

       /// <summary>

        /// 获取后台供卖家发布商品的标准商品类目(获取品牌型号)



       /// </summary>

       /// <param name="parent_cid"></param>

       /// <param name="cids"></param>

       /// <param name="fields"></param>

       /// <returns></returns>

        public HttpWebResponse taobao_itemcats_get_v2(string parent_cid, string cids, string fields)

        {

            Util.ParamsBuild pb = new Util.ParamsBuild(SessionID, "taobao.itemcats.get.v2");



            if (parent_cid.Length != 0 || cids.Length != 0)

            {

                if (parent_cid != "")

                {

                    pb.AddParam("parent_cid", parent_cid);//



                }

                if (cids != "")

                {

                    pb.AddParam("cids", cids);//



                }

            }

            pb.AddParam("fields", fields);

            pb.AddParam("v", VERSION);

            string data = pb.GetURL();



            return Util.HttpRequest3(data);

        }



      

        #endregion





    }

孟子E章 2012-07-24

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贴你的mydoc.OuterXml代码

孟子E章 2012-07-24

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mydoc.SelectSingleNode("/rsp/totalResults")的结果是 null了

孟子E章 2012-07-24

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那些代码没有用，你就看
myapi = new taobaoApi();
XmlDocument mydoc = myapi.taobao_items_get("", "iid,title,nick,type,cid,pic_path,delist_time,price,post_fee", 0, 0, "鑫名品")

这里返回的mydoc 的内容。可以没有返回内容或者返回的格式不一样