未将对象引用设置为Webservice中对象的实例

在我的项目中我有一个WebService用于生成列表，当我运行WebService时，我在c:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Config\DefaultWsdlHelpGenerator.aspx中获得NullReference Exception。未将对象引用设置为Webservice中对象的实例

有人可以指我在我的代码中有什么问题吗？

我试过的代码是：

我得到

using System; 
    using System.Collections.Generic; 
    using System.Linq; 
    using System.Web; 
    using System.Web.Services; 
    using System.Data.SqlClient; 
    using System.Data; 
    using SubSonic; 

    [WebService(Namespace = "http://tempuri.org/")] 
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)] 
    [System.ComponentModel.ToolboxItem(false)] 
    [System.Web.Script.Services.ScriptService] 
public class AutoComplete : System.Web.Services.WebService 
{ 
public AutoComplete() 
{ 
    //InitializeComponent(); 
} 

public string[] Getlist(string keywordstartswith) 
    { 
    IList<string> output = new List<string>(); 
    Dictionary<string, string> mydict = new Dictionary<string, string>(); 
    string QueryString = System.Configuration.ConfigurationManager.ConnectionStrings ["IUMSNXG"].ToString(); 
    IDataReader obj_result = SearchApp.DBCon.LRS_SP_CBFM_Sel(keywordstartswith).GetReader(); 
    DataTable dt = new DataTable(); 
    dt.Load(obj_result); 
    if(dt.Rows.Count > 0) 
    { 
     while (obj_result.Read()) 
     { 
      output.Add(string.Format("{0}~{1}", obj_result["AnimalCode"].ToString().TrimEnd(), obj_result["pk_animalid"].ToString().TrimEnd())); 
     } 
    } 
    return output.ToArray(); 
    } 
}

的源错误是：

Line 1333: 
Line 1334: OperationBinding FindHttpBinding(string verb) { 
Line 1335:  foreach (ServiceDescription description in serviceDescriptions) // Getting Error Here 
        { 
Line 1336:   foreach (Binding binding in description.Bindings) { 
Line 1337:    HttpBinding httpBinding = (HttpBinding)binding.Extensions.Find(typeof(HttpBinding));

堆栈跟踪是

[NullReferenceException: Object reference not set to an instance of an object.] 
    ASP.defaultwsdlhelpgenerator_aspx.FindHttpBinding(String verb) in c:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Config\DefaultWsdlHelpGenerator.aspx:1335 
    ASP.defaultwsdlhelpgenerator_aspx.get_HttpPostOperationBinding() in c:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Config\DefaultWsdlHelpGenerator.aspx:526 
    ASP.defaultwsdlhelpgenerator_aspx.get_ShowingHttpPost() in c:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Config\DefaultWsdlHelpGenerator.aspx:541 
    ASP.defaultwsdlhelpgenerator_aspx.__Render__control20(HtmlTextWriter __w, Control parameterContainer) in c:\WINDOWS\Microsoft.NET\Framework\v4.0.30319 \Config\DefaultWsdlHelpGenerator.aspx:1574 
    System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +109 
    System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +8 
    System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +31 
    System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 
    System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +100 
    System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 
    System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +208 
    System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +8 
    System.Web.UI.Page.Render(HtmlTextWriter writer) +29 
    System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 
    System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +100 
    System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 
    System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3060

来源

2013-06-24 Rajesh

你的代码在哪里出错？ –

@ Kostas错误是不是在我创建的代码文件中，** Nullreference Exception **在'DefaultWsdlHelpGenerator.aspx' – Rajesh

@Rajesh但是哪一行？ –

[的WebMethod]属性从您的WebMethod中丢失。试着写你的Web方法一样，

 [WebMethod] 
     public string[] Getlist(string keywordstartswith) 
     { 
      IList<string> output = new List<string>(); 
      Dictionary<string, string> mydict = new Dictionary<string, string>(); 
      string QueryString = System.Configuration.ConfigurationManager.ConnectionStrings["IUMSNXG"].ToString(); 
      IDataReader obj_result = SearchApp.DBCon.LRS_SP_CBFM_Sel(keywordstartswith).GetReader(); 
      DataTable dt = new DataTable(); 
      dt.Load(obj_result); 
      if (dt.Rows.Count > 0) 
      { 
       while (obj_result.Read()) 
       { 
        output.Add(string.Format("{0}~{1}", obj_result["AnimalCode"].ToString().TrimEnd(), obj_result["pk_animalid"].ToString().TrimEnd())); 
       } 
      } 
      return output.ToArray(); 
     }

装上[的WebMethod]属性的公共方法表明你想要的方法公开为XML Web服务

来源

2013-06-24 12:43:17 Rezoan

解释我有在我的Web方法的顶部使用'[WebMethod]'编辑，但在运行相同的异常时发生。 – Rajesh

顺便问一下，请确认我：只是创建一个全新的asp.net web服务，而不做任何事情只是尝试运行它，并成功运行？@ Rajesh – Rezoan

我已经创建了一个没有代码的新鲜Web服务，试图运行它，但同样的异常被抛出。 – Rajesh

的ASP.Net的一部分如果为您的网站禁用AutoEventWireup，则生成用于获取对asmx资源的请求的输出的处理程序不起作用。这是不幸的，因为禁用这是性能最佳实践。 Enable it in your web.config暂时关闭，完成后关闭。

（帽尖到Bryan Allott）

来源

2015-03-03 21:46:16 bmm6o

作为一种解决方案可以添加<％@页autoEventWireup = “真” ％>顶端使用c：\ Windows \ Microsoft.NET \框架\ v4.0.30319 \ Config \ DefaultWsdlHelpGenerator.aspx

来源

2016-01-26 15:06:57 Alina

未将对象引用设置为Webservice中对象的实例

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