C＃从HttpResponseMessage读取

Question

I am using .net's Httpclient for the first time and finding it very hard. I have managed to call the server and receive response from it but stuck at reading from the response. Here is my code:

if (Method == HttpVerb.POST)
     response = client.PostAsync(domain, new StringContent(parameters)).Result;
else
     response = client.GetAsync(domain).Result;

if (response != null)
{
     var responseValue = string.Empty;

     Task task = response.Content.ReadAsStreamAsync().ContinueWith(t =>
     {
         var stream = t.Result;
         using (var reader = new StreamReader(stream))
         {
             responseValue = reader.ReadToEnd();
         }
     });


     return responseValue;
}

responseValue has {} in it although the service is returning data. How should I fix the issue?

The project is in .Net 4.

Answer 1

You are creating an asynchronous task but not waiting for it to complete before returning. This means your responseValue never gets set.

To fix this, before your return do this:

task.Wait();

So your function now looks like this:

if (Method == HttpVerb.POST)
     response = client.PostAsync(domain, new StringContent(parameters)).Result;
else
     response = client.GetAsync(domain).Result;

if (response != null)
{
     var responseValue = string.Empty;

     Task task = response.Content.ReadAsStreamAsync().ContinueWith(t =>
     {
         var stream = t.Result;
         using (var reader = new StreamReader(stream))
         {
             responseValue = reader.ReadToEnd();
         }
     });

     task.Wait();

     return responseValue;
}

If you prefer to use await (which you possibly should), then you need to make the function this code is contained in async . So this:

public string GetStuffFromSomewhere()
{
    //Code above goes here

    task.Wait();
}

Becomes:

public async string GetStuffFromSomewhere()
{
    //Code above goes here

    await ...
}

Answer 2

Try this

                    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(obj.Url);
                    HttpWebResponse response = null;

                    try
                    {
                        response = request.GetResponse() as HttpWebResponse;
                    }
                    catch (Exception ex)
                    {
                    }