C# 无法在return语句中返回xml

我仍在尝试从webservuce创建以下代码，但由于某些原因，当返回值为null时，即使在调试xml字符串值时，返回值仍为indead

public XmlTextReader readXML(string postcode, string response, string accessCode)
{
   WebRequest wrURL;
   Stream objStream;
   string strURL;
   string url = "http://pcls1.craftyclicks.co.uk/xml/rapidaddress?postcode=" + postcode + "&response=" + response + "&key=" + accessCode;
   wrURL = WebRequest.Create(url);
   string xml = new WebClient().DownloadString(url);

   objStream = wrURL.GetResponse().GetResponseStream();
   StreamReader objSReader = new StreamReader(objStream);
   strURL = objSReader.ReadToEnd().ToString(); #####but here it has the xml data ?####
   XmlTextReader reader = new XmlTextReader(new StringReader(strURL));
return reader;#######here its empty ????#####
 }

编辑

我在这里仍然没有得到响应，但是当我在实际的浏览器中从代码中生成的url查看它时，它会显示以下内容

<CraftyResponse><address_data_formatted><delivery_point><organisation_name>THE BAKERY</organisation_name><department_name/><line_1>1 HIGH STREET</line_1><line_2>CRAFTY VALLEY</line_2><udprn>12345678</udprn></delivery_point><delivery_point><organisation_name>FILMS R US</organisation_name><department_name/><line_1>3 HIGH STREET</line_1><line_2>CRAFTY VALLEY</line_2><udprn>12345679</udprn></delivery_point><delivery_point><organisation_name>FAMILY BUTCHER</organisation_name><department_name/><line_1>7 HIGH STREET</line_1><line_2>CRAFTY VALLEY</line_2><udprn>12345680</udprn></delivery_point><delivery_point><organisation_name/><department_name/><line_1>BIG HOUSE, HIGH STREET</line_1><line_2>CRAFTY VALLEY</line_2><udprn>12345681</udprn></delivery_point><delivery_point><organisation_name/><department_name/><line_1>LITTLE COTTAGE</line_1><line_2>17 HIGH STREET, CRAFTY VALLEY</line_2><udprn>12345682</udprn></delivery_point><delivery_point_count>5</delivery_point_count><town>BIG CITY</town><postal_county>POSTAL COUNTY</postal_county><traditional_county>TRADITIONAL COUNTY</traditional_county><postcode>AA1 1AA</postcode></address_data_formatted></CraftyResponse>

用于显示调试的动画gif

---

< P>当使用<代码> IDISPABLE < /Cord>对象时，应考虑使用<代码>使用

public XmlTextReader readXML(string postcode, string response, string accessCode)
{            
   string strURL = string.Empty;
   string url = "http://pcls1.craftyclicks.co.uk/xml/rapidaddress?postcode=" + postcode + "&response=" + response + "&key=" + accessCode;
   WebRequest wrURL = WebRequest.Create(url);      
   //string xml = new WebClient().DownloadString(url); //What is this for ? I dont see you using this in your code ?!
   using(Stream objStream = wrURL.GetResponse().GetResponseStream())
   {
      using(StreamReader objSReader = new StreamReader(objStream))
      {                
         return new XmlTextReader(new StringReader(objSReader.ReadToEnd()));
      }//Dispose the StreamReader
   }//Dispose the Stream             
 }

如果提供的代码修复了它，请尝试

编辑：

public XmlTextReader ReadXml(string postcode, string response, string accessCode)
    {
        //Create URL
        string url = $"http://pcls1.craftyclicks.co.uk/xml/rapidaddress?postcode={postcode}&response={response}&key={accessCode}";

        try
        {
            //Create WebRequest
            WebRequest request = WebRequest.Create(url);
            using (Stream responseStream = request.GetResponse().GetResponseStream())
            {
                if (responseStream != null)
                {
                    using (TextReader textReader = new StreamReader(responseStream))
                    {
                        XmlTextReader reader = new XmlTextReader(textReader);
                        Debug.Assert(reader != null, "Reader is NULL");
                        return reader;
                    }
                }
                throw new Exception("ResponseStream is NULL");
            }
        }
        catch (WebException ex)
        {
            //Handle exceptions here
            throw;
        }
    }

要缩短代码，您可以使用：

string url = $"http://pcls1.craftyclicks.co.uk/xml/rapidaddress?postcode={postcode}&response={response}&key={accessCode}";    
using(Stream objStream = WebRequest.Create(url)?.GetResponse().GetResponseStream())
{                     
   return new XmlTextReader(new StringReader(new StreamReader(objStream)?.ReadToEnd()));
}//Dispose the Stream

编辑：

public XmlTextReader ReadXml(string postcode, string response, string accessCode)
    {
        //Create URL
        string url = $"http://pcls1.craftyclicks.co.uk/xml/rapidaddress?postcode={postcode}&response={response}&key={accessCode}";

        try
        {
            //Create WebRequest
            WebRequest request = WebRequest.Create(url);
            using (Stream responseStream = request.GetResponse().GetResponseStream())
            {
                if (responseStream != null)
                {
                    using (TextReader textReader = new StreamReader(responseStream))
                    {
                        XmlTextReader reader = new XmlTextReader(textReader);
                        Debug.Assert(reader != null, "Reader is NULL");
                        return reader;
                    }
                }
                throw new Exception("ResponseStream is NULL");
            }
        }
        catch (WebException ex)
        {
            //Handle exceptions here
            throw;
        }
    }

你能试试这个片段吗

旁注：

public XmlTextReader ReadXml(string postcode, string response, string accessCode)
    {
        //Create URL
        string url = $"http://pcls1.craftyclicks.co.uk/xml/rapidaddress?postcode={postcode}&response={response}&key={accessCode}";

        try
        {
            //Create WebRequest
            WebRequest request = WebRequest.Create(url);
            using (Stream responseStream = request.GetResponse().GetResponseStream())
            {
                if (responseStream != null)
                {
                    using (TextReader textReader = new StreamReader(responseStream))
                    {
                        XmlTextReader reader = new XmlTextReader(textReader);
                        Debug.Assert(reader != null, "Reader is NULL");
                        return reader;
                    }
                }
                throw new Exception("ResponseStream is NULL");
            }
        }
        catch (WebException ex)
        {
            //Handle exceptions here
            throw;
        }
    }

XmlTextReader

中还有另一个重载，如下所示：

公共XmlTextReader（字符串url）

你也可以试试这个
 请让我们也提供输入字符串，以便我们可以看到您代码中的突出部分。此外，您不应该执行
new WebClient（）。下载字符串（url）
，因为
WebClient
是
IDisposable
的，所以您必须保留一个要处理的引用。对我来说，这还不清楚。您是如何发现
读卡器
为空的？
读卡器是否为空？还是读者的阅读没有任何回报？它是读取
null
还是读取空字符串？请提供一个。请查看我在上面所做的编辑。您是否可以尝试Hi使用（WebRequest wrURL=WebRequest.Create（url））此处有错误说它不能转换为IDisposable？@david yeah我的失败-.-
WebRequest
没有实现
IDisposable
，所以你不能使用
使用
-我修复了我的答案，但仍然没有返回任何信息-（@David，你真的想返回XmlTextReader？或者简单地返回你在响应中得到的xml？它说读卡器为空，但我不明白那蜜蜂怎么可能不在防火墙上？当我将其放入浏览器url时，所有端口80流量都是允许的