通过WebRequest下载“ Visual Studio Team Services”图表

Question

I need to upgrade an old TFS 2013 class for Visual Studio Team Services . To get the Burndown-Chart I used to download the image via HttpWebRequest direcly from the url.

Somehow Iam not able to do this in VSTS . I always get the error message "invalid parameters" . Everything else works fine. (I had to setup the Alternate authentication credentials in my profile to get it working for my application)

Here my code:

    public Image GetChart(string uri)
    {
        HttpWebRequest httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(uri);
        httpWebRequest.Credentials = new NetworkCredential("MyUserNameForApplication", "MyPWForApplication");
        using (HttpWebResponse httpWebReponse = (HttpWebResponse)httpWebRequest.GetResponse())
        {
            using (Stream stream = httpWebReponse.GetResponseStream())
            {
                return Image.FromStream(stream); //Error occourse
            }
        }
    }

The url which gets passed as a parameter usally looks like this:

https://YourVSName.visualstudio.com/DefaultCollection/a5d2310b-d3f8-4365-b693-3826ab60e939/_api/_teamChart/Burndown?chartOptions= {%22Width%22%3A1248%2C%22Height%22%3A161%2C%22ShowDetails%22%3Atrue%2C%22Title%22%3A%22%22}&counter=1&iterationPath=Developing\\Sprint+1&__v=5

What I think the problem is:

First I thought this might be a security issue , because this code is able to download normal google images. And when I try to get the content of the url It returns a lot of code with a message in it:

Microsoft Internet Explorer's Enhanced Security Configuration is currently enabled on your environment. This enhanced level of security prevents our web integration experiences from displaying or performing correctly. To continue with your operation please disable this configuration or contact your administrator

I set my Internet security settings to the lowest level and still the same result.

Another reason why this might not working is, because the url linking to the burndown-chart doesnt contain an Image extension . Iam not quite shure here this effects the result.

Or that the parameters which are getting past in the url are incorrect...

What I have tried so far:

I have used bunch of other code to get the image from that link. For example using WebClient or tried to upload cookies (credentials) to the tfs and than tried to connect.

My Question

Is it possible to get that image from the chart via url, and if so, how?

Thanks for any kind of help :).

EDIT

Currently Iam using this code (Thanks to @Eddie - MSFT):

 public static async void GetChart(string uri,string username, string password)
        {
            try
            {
                using (HttpClient client = new HttpClient())
                {
                    client.DefaultRequestHeaders.Accept.Add(
                        new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));

                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic",
                    Convert.ToBase64String(
                        System.Text.ASCIIEncoding.ASCII.GetBytes(
                            string.Format("{0}:{1}", username, password))));

                using (HttpResponseMessage response = client.GetAsync(uri).Result)
                {
                    response.EnsureSuccessStatusCode();
                    var responseStream = await response.Content.ReadAsStreamAsync();
                    var img =  Image.FromStream(responseStream);
                }
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.ToString());
        }
    }



 static void Main(string[] args)
     {
                string uri = "https://Name.visualstudio.com/DefaultCollection/a5d2310b-d3f8-4365-b693-3826ab60e939/_api/_teamChart/Burndown?chartOptions=%7B%22Width%22%3A1248%2C%22Height%22%3A636%2C%22ShowDetails%22%3Atrue%2C%22Title%22%3A%22%22%7D&counter=1&iterationPath=Developing%5CSprint+1&__v=5";
                TFSHelper.TFSHelper.GetChart(uri, username,pw)
     }

Answer 1

I use "httpclient" with alternative credential to do this:

using System.Text;
using System.Threading.Tasks;
using System.Drawing;
using System.Net.Http;
using System.Net.Http.Headers;
using System.IO;

namespace GetImageA
{
    class Program
    {
        static void Main(string[] args)
        {
            Uri uri = new Uri("your image uri");
            GetImage(uri);
        }
        public static void GetImage(Uri uri)
        {
                var username = "username";
                var password = "password";

                using (HttpClient client = new HttpClient())
                {
                    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

                    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic",
                        Convert.ToBase64String(
                            ASCIIEncoding.ASCII.GetBytes(
                                string.Format("{0}:{1}", username, password))));
                    Stream str = client.GetStreamAsync(uri).Result;
                    Image im = Image.FromStream(str);
                    im.Save("E:\\image.png");
                }
        }
    }
}

Answer 2

Did you try the authentication with your personal access token instead of username and password, something like this? I am using the below code to download the attachments, inline images of the Work items from VSTS.

try
   {
     var personalaccesstoken = "Your_VSTS_Personal_Access_Token";

     using (HttpClient client = new HttpClient())
     {
        client.DefaultRequestHeaders.Accept.Add(
            new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));

        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic",
            Convert.ToBase64String(
                System.Text.ASCIIEncoding.ASCII.GetBytes(
                    string.Format("{0}:{1}", "", personalaccesstoken))));

        using (HttpResponseMessage response = client.GetAsync(uri).Result)
        {
            response.EnsureSuccessStatusCode();
            string responseBody = await response.Content.ReadAsStringAsync();
            Console.WriteLine(responseBody);
        }
    }
}
catch (Exception ex)
{
    Console.WriteLine(ex.ToString());
}