是否可以將數據從C＃應用程序發送到網站/網絡服務器？

Question

我希望有人能幫助我一段令我困惑的問題。

是否有可能在打開瀏覽器時將數據從C＃應用程序發送到網頁，例如：如果你有一個在線登錄表單，並想從你的C＃應用​​程序發佈一個用戶名和密碼到該表單。

我看到像打開的瀏覽器的頁面形式和程序發佈登錄信息到該頁面後，頁面可以處理的形式馬上從而在登錄並將其發送到首頁。這可能嗎？

在此先感謝

保羅

Answer 1

肯定。

您可以使用HttpWebRequest與網頁或Web服務器（或Web服務）進行通信。這是實際的代碼，我用它來從Facebook網址獲取數據：

internal static string FbFetch(string url) 
{ 
    var request = (HttpWebRequest)WebRequest.Create(url); 
    request.Method = "GET"; 
    using (var response = (HttpWebResponse)request.GetResponse()) 
    { 
     using (var reader = new StreamReader(response.GetResponseStream())) 
     { 
      var responseText = reader.ReadToEnd(); 
      return responseText; 
     } 
    } 
} 

不過，你描述的被稱爲「HTML屏幕抓取」什麼，它可以用於構建應用程序的一個繁瑣而脆的方法。單調乏味，因爲很難瀏覽所有的UI糖果，而且很脆弱，因爲如果頁面設計師改變他的頁面，你的屏幕抓取將不再起作用。

祝你好運。

Answer 2

要回答你關於HTTP帖子（附件）的問題，它更難 - 因爲附件。這是我用來將圖像發佈到FaceBook的實際代碼。

/// <summary> 
    /// Create a new HttpWebRequest with the default properties for HTTP POSTS 
    /// </summary> 
    /// <param name="url">The URL to be posted to</param> 
    /// <param name="referer">The refer</param> 
    /// <param name="cookies">CookieContainer that should be used in this request</param> 
    /// <param name="postData">The post data</param> 
    private string CreateHttpWebUploadRequest(string url, string referer, CookieContainer cookies, NameValueCollection postData, FileInfo fileData, string fileContentType) 
    { 
     HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url); 
     string boundary = "----------" + DateTime.UtcNow.Ticks.ToString("x", CultureInfo.InvariantCulture); 

     // set the request variables 
     request.Method = WebRequestMethods.Http.Post; 
     request.ContentType = "multipart/form-data; boundary=" + boundary; 
     request.CookieContainer = cookies; 
     request.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/533.4 (KHTML, like Gecko) Chrome/5.0.375.55 Safari/533.4"; 
     request.Accept = "image/gif, image/jpeg, image/pjpeg, image/pjpeg, */*"; 
     request.Headers.Add("Accept-Encoding: gzip,deflate"); 
     request.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip; 
     request.Headers.Add("Accept-Language: en-us"); 
     request.Referer = referer; 
     request.KeepAlive = true; 
     request.AllowAutoRedirect = false; 

     // process through the fields 
     StringBuilder sbHeader = new StringBuilder(); 

     // add form fields, if any 
     if (postData != null) 
     { 
      foreach (string key in postData.AllKeys) 
      { 
       string[] values = postData.GetValues(key); 
       if (values != null) 
       { 
        foreach (string value in values) 
        { 
         if (!string.IsNullOrEmpty(value)) 
          sbHeader.AppendFormat("--{0}\r\n", boundary); 
          sbHeader.AppendFormat("Content-Disposition: form-data; name=\"{0}\";\r\n\r\n{1}\r\n", key, value); 
        } 
       } 
      } 
     } 

     if (fileData != null) 
     { 
      sbHeader.AppendFormat("--{0}\r\n", boundary); 
      sbHeader.AppendFormat("Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\n", "media", fileData.Name); 
      sbHeader.AppendFormat("Content-Type: {0}\r\n\r\n", fileContentType); 
     } 

     byte[] header = Encoding.UTF8.GetBytes(sbHeader.ToString()); 
     byte[] footer = Encoding.UTF8.GetBytes("\r\n--" + boundary + "--\r\n"); 
     long contentLength = header.Length + (fileData != null ? fileData.Length : 0) + footer.Length; 

     // set content length 
     request.ContentLength = contentLength; 

     using (Stream requestStream = request.GetRequestStream()) 
     { 
      requestStream.Write(header, 0, header.Length); 

      // write the uploaded file 
      if (fileData != null) 
      { 
       // write the file data, if any 
       byte[] buffer = new Byte[fileData.Length]; 
       var bytesRead = fileData.OpenRead().Read(buffer, 0, (int)(fileData.Length)); 
       requestStream.Write(buffer, 0, bytesRead); 
      } 

      // write footer 
      requestStream.Write(footer, 0, footer.Length); 
      requestStream.Flush(); 
      requestStream.Close(); 

      using (var response = request.GetResponse() as HttpWebResponse) 
      { 
       using (var stIn = new System.IO.StreamReader(response.GetResponseStream())) 
       { 
        return stIn.ReadToEnd(); 
       } 
      } 
     } 
    } 

更新 並使其完整，這裏是不需要的文件附件職位的代碼。再次，我使用此代碼發佈到FaceBook。

/// <summary> 
    /// Create a new HttpWebRequest with the default properties for HTTP POSTS 
    /// </summary> 
    /// <param name="url">The URL to be posted to</param> 
    /// <param name="referer">The refer</param> 
    /// <param name="cookies">CookieContainer that should be used in this request</param> 
    /// <param name="postData">The post data (needs to be formatted in name=value& format</param> 
    private string CreateHttpWebPostRequest(string url, string referer, CookieContainer cookies, NameValueCollection postData) 
    { 
     var sbPostData = new StringBuilder(); 

     if (postData != null) 
     { 
      foreach (string key in postData.AllKeys) 
      { 
       string[] values = postData.GetValues(key); 
       if (values != null) 
       { 
        foreach (string value in values) 
        { 
         if (!string.IsNullOrEmpty(value)) 
          sbPostData.Append(string.Format("{0}={1}&", HttpUtility.UrlEncode(key), HttpUtility.UrlEncode(value))); 
        } 
       } 
      } 
     } 

     var parameterString = Encoding.UTF8.GetBytes(sbPostData.ToString()); 
     HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url); 
     request.Method = WebRequestMethods.Http.Post; 
     request.CookieContainer = cookies; 
     request.ContentLength = parameterString.Length; 
     request.ContentType = "application/x-www-form-urlencoded"; 
     request.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/533.4 (KHTML, like Gecko) Chrome/5.0.375.55 Safari/533.4"; 
     request.Accept = "image/gif, image/jpeg, image/pjpeg, image/pjpeg, */*"; 
     request.Headers.Add("Accept-Encoding: gzip,deflate"); 
     request.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip; 
     request.Headers.Add("Accept-Language: en-us"); 
     request.Referer = referer; 
     request.KeepAlive = true; 
     request.AllowAutoRedirect = false; 

     using (Stream requestStream = request.GetRequestStream()) 
     { 
      requestStream.Write(parameterString, 0, parameterString.Length); 
      requestStream.Close(); 

      using (var response = request.GetResponse() as HttpWebResponse) 
      { 
       using (var stIn = new System.IO.StreamReader(response.GetResponseStream())) 
       { 
        return stIn.ReadToEnd(); 
       } 
      } 
     } 
    } 

Answer 3

您可以直接在C＃中自動執行webbrowser control。與HttpWebRequest不同，這將與任何網站一起使用。

但如果你有更多的錢比時，可考慮使用商業component。