how can I make the httprequest stop if internet is slow and data is not gather within 10 seconds?

Question

I get crashes when I work with my app with a slow internet when I keep pressing different buttons that gathers data via httprequests. how could i make a function so that if i do not recieve the data within for example 10 seconds, the attempt to gather the data from the httprequest should be cancelled.

This is my code:

static public async Task<JObject> getCategories ()
    {
        var httpClientRequest = new HttpClient ();
        try {
        var result = await httpClientRequest.GetAsync ("http://localhost");
        var resultString = await result.Content.ReadAsStringAsync ();

        var jsonResult = JObject.Parse (resultString);

        System.Diagnostics.Debug.WriteLine (resultString);

        return jsonResult;
    }

        catch {

            return null;
        }

    }



async void createCategory (object sender, EventArgs args)
{
var getCategory = await parseAPI.getCategories ();

if (getCategory != null) {

foreach (var currentItem in getItems["results"]) {
    id = currentItem ["ID"].ToString ();
    objectid = currentItem ["objectid"].ToString ();

    //connected
    }

  }
        } else {

            //no connection

        }
   }

Ehsan Sajjad · Answer 1 · 2016-05-05T22:44:38.053

2

You can use CancellationTokenSource which has a method provided in it which is CancelAfter():

 var token = new CancellationTokenSource();
 token.CancelAfter(10000); // after 10 secs
 var result = await httpClientRequest.GetAsync ("http://localhost",token.Token);
 var resultString = await result.Content.ReadAsStringAsync ();

Here is a article about using Cancellation with GetAsync which you may be interested to read.

edited May 05 '16 at 22:44

answered May 05 '16 at 22:09

Ehsan Sajjad

61,834
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I cannot find "CancellationTokenSource" – medvedo May 05 '16 at 22:11
I cannot find GetStringAsync – medvedo May 05 '16 at 22:15
var result = await httpClientRequest.GetAsync ("http://localhost",token);, It does not let me add token after the http – medvedo May 05 '16 at 22:41
try changing : ``httpClientRequest.GetAsync ("http://localhost",token);`` to : ``httpClientRequest.GetAsync ("http://localhost",token.Token);`` – Ehsan Sajjad May 05 '16 at 22:44
Code runs but does not cancell the request after (in my case) 1 second. – medvedo May 05 '16 at 22:46
take a look here : http://stackoverflow.com/questions/10715688/is-cancellationtokensource-cancelafter-leaky – Ehsan Sajjad May 05 '16 at 22:51

score 1 · Answer 2 · answered May 05 '16 at 22:14

1

You could also use the timeout on the httpclient.

        var httpClientRequest = new HttpClient();
        httpClientRequest.Timeout = TimeSpan.FromSeconds(10);
        var result = await httpClientRequest.GetAsync("http://localhost");

answered May 05 '16 at 22:14

wishmaster

1,303
8
15

should I use the timeout inside the try function? – medvedo May 05 '16 at 22:19
Yes of course! It will trigger a TaskCanceledException. – wishmaster May 05 '16 at 22:25
Seems like it doesnt work. I made it 1 second just to try it out. And it does not reach the else (//no connection) code after 1 second. – medvedo May 05 '16 at 22:29
is the result coming back with something else than null ? You should add a GetAsync ("http://localhost").ConfigureAwait(false) to your Async calls to avoid capturing the current context – wishmaster May 05 '16 at 22:35
It returns a result but it takes 5 seconds (for my slow wifi) to recieve it and I have put the timeout to 1 second, so it shouldnt even get a result – medvedo May 05 '16 at 22:48

how can I make the httprequest stop if internet is slow and data is not gather within 10 seconds?

2 Answers2