如何从Post方法响应中解析xml字符串？

Question

我有一个XML字符串，从Post方法返回：

private static void GetResponseCallback(IAsyncResult asynchronousResult) 
{ 
    HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState; 

    // End the operation 
    HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult); 
    HttpStatusCode rcode = response.StatusCode; 

    var stream = new GZipInputStream(response.GetResponseStream()); 
    using (StreamReader reader = new StreamReader(stream)) 
    { 
     responseString = reader.ReadToEnd();     
    }   

    response.Close(); 
} 

的responseString是我想分析该字符串，用下面parseXmlString类。但是，由于静态，我无法直接调用parseXmlString方法。我怎样才能将responseString传递给parseXmlString方法来解析并绑定到列表框。或者无论如何，有相同的结果会很好。

void parseXmlString() 
{ 
    byte[] byteArray = Encoding.UTF8.GetBytes(responseString); 
    MemoryStream str = new MemoryStream(byteArray); 
    str.Position = 0; 

    XDocument xdoc = XDocument.Load(str); 

    var data = from query in xdoc.Descendants("tracks").Elements("item") 
       select new searchResult 
       { 
        artist = (string)query.Element("artist"), 
        album = (string)query.Element("album"), 
        track = (string)query.Element("track"), 
        // artistA = (string)query.Element("artists").Element("artist"), 
       }; 
    // ListBox lb = new ListBox(); 

    listBox1.ItemsSource = data; 

    var data1 = from query in xdoc.Descendants("artists").Elements("item") 
       select new searchResult 
       { 
        artistA = (string)query.Element("artist"), 
       }; 
    listBox2.ItemsSource = data1; 
} 

Answer 1

你的方法是反转逻辑。你知道你可以有方法的返回值，右 - ）

什么，你需要做的是让你的ParseXmlString方法采取responseString作为参数，让它返回创建IEnumerable，是这样的：

private IEnumerable<SearchResult> ParseXmlString(responseString) 
{ 
    XDocument xdoc = XDocument.Load(responseString); 

    var data = 
     from query in xdoc.Descendants("tracks").Elements("item") 
     select new SearchResult 
     { 
      Artist = (string)query.Element("artist"), 
      Album = (string)query.Element("album"), 
      Track = (string)query.Element("track"), 
     }; 

    return 
     from query in xdoc.Descendants("artists").Elements("item") 
     select new SearchResult 
     { 
      ArtistA = (string)query.Element("artist"), 
     }; 
} 

并且在完成读取responseString的操作后，更改异步代码处理，执行对UI线程的回调。 然后，在你的UI线程，你会怎么做：

// This being your method to get the async response 
GetResponseAsync(..., responseString => 
{ 
    var searchResults = ParseXmlString(responseString); 
    listBox2.ItemsSource = searchResults; 
}) 

你可以看到这个答案，如果你需要回调的一些基本认识：Callbacks in C#