Question

I have an API in NETMF C# that I am writing that includes a function to send an HTTP request. For those who are familiar with NETMF, this is a heavily modified version of the “webClient” example, which a simple application that demonstrates how to submit an HTTP request, and recive a response. In the sample, it simply prints the response and returns void,. In my version, however, I need it to return the HTTP response.

For some reason, Visual Studio reports that not all code paths return a value, even though, as far as I can tell, they do.

Here is my code…

  /// <summary>
  /// This is a modified webClient
  /// </summary>
  /// <param name="url"></param>
  private string httpRequest(string url)
  {
   // Create an HTTP Web request.
   HttpWebRequest request = HttpWebRequest.Create(url) as HttpWebRequest;

   // Set request.KeepAlive to use a persistent connection. 
   request.KeepAlive = true;

   // Get a response from the server.
    WebResponse resp = request.GetResponse();

   // Get the network response stream to read the page data.
   if (resp != null)
   {
    Stream respStream = resp.GetResponseStream();
    string page = "";
    byte[] byteData = new byte[4096];
    char[] charData = new char[4096];
    int bytesRead = 0;
    Decoder UTF8decoder = System.Text.Encoding.UTF8.GetDecoder();
    int totalBytes = 0;

    // allow 5 seconds for reading the stream
    respStream.ReadTimeout = 5000;

    // If we know the content length, read exactly that amount of 
    // data; otherwise, read until there is nothing left to read.
    if (resp.ContentLength != -1)
    {
     for (int dataRem = (int)resp.ContentLength; dataRem > 0; )
     {
      Thread.Sleep(500);
      bytesRead = respStream.Read(byteData, 0, byteData.Length);

      if (bytesRead == 0)
       throw new Exception("Data laes than expected");

      dataRem -= bytesRead;

      // Convert from bytes to chars, and add to the page 
      // string.
      int byteUsed, charUsed;
      bool completed = false;
      totalBytes += bytesRead;
      UTF8decoder.Convert(byteData, 0, bytesRead, charData, 0,
       bytesRead, true, out byteUsed, out charUsed,
       out completed);
      page = page + new String(charData, 0, charUsed);
     }

     page = new String(System.Text.Encoding.UTF8.GetChars(byteData));
    }
    else
     throw new Exception("No content-Length reported");

    // Close the response stream.  For Keep-Alive streams, the 
    // stream will remain open and will be pushed into the unused 
    // stream list.
    resp.Close();
    return page;
   }
  }

Any ideas? Thanks…

Answer 1

Clearly, if (resp == null) then you still need to return something…