How to properly make a http web GET request

Question

i am still new on c  and i m trying to create an application for this page that will tell me when i get a notification  answered  commented  etc     But for now i m just trying to make a simple call to the api which will get the user s data   i m using Visual studio express 2012 to build the C  application  where  for now  you enter your user id  so the application will make the request with the user id and show the stats of this user id   here is the code where i m trying to make the request   using System  using System Collections Generic  using System Linq  using System Text  using System Threading Tasks    Request library using System Net  using System IO   namespace TestApplication       class Connect               public string id          public string type           protected string api    https   api stackexchange com 2 2            protected string options     order desc amp sort name amp site stackoverflow            public string request                         string totalUrl   this join id                return this HttpGet totalUrl                      protected string join string s                        return api   type         s   options                     protected string get string url                        try                               string rt                   WebRequest request   WebRequest Create url                    WebResponse response   request GetResponse                     Stream dataStream   response GetResponseStream                     StreamReader reader   new StreamReader dataStream                    rt   reader ReadToEnd                     Console WriteLine rt                    reader Close                    response Close                     return rt                             catch Exception ex                                return  Error      ex Message                                  public string HttpGet string URI                        WebClient client   new WebClient                    Add a user agent header in case the                 requested URI contains a query               client Headers Add  user-agent    Mozilla 4 0  compatible  MSIE 6 0  Windows NT 5 2   NET CLR 1 0 3705                   Stream data   client OpenRead URI               StreamReader reader   new StreamReader data               string s   reader ReadToEnd                data Close                reader Close                 return s                      the class is an object and its being accessed from the form by just parsing it the user id and make the request   i have tried many of the examples i have looked on google  but not clue why i am getting on all ways this message       i am new in this kind of algorithm  if anyone can share a book or tutorial that shows how to do this kind of stuff  explaining each step   i would appreciate it

User · Answer

var request    HttpWebRequest WebRequest Create  sendrequesturl    var response    HttpWebResponse request GetResponse    string responseString  using  var stream   response GetResponseStream          using  var reader   new StreamReader stream                 responseString   reader ReadToEnd

User · Answer

Servers sometimes compress their responses to save on bandwidth  when this happens  you need to decompress the response before attempting to read it  Fortunately  the  NET framework can do this automatically  however  we have to turn the setting on  Here s an example of how you could achieve that  string html   string Empty  string url     quot https   api stackexchange com 2 2 answers order desc amp sort activity amp site stackoverflow quot    HttpWebRequest request    HttpWebRequest WebRequest Create url   request AutomaticDecompression   DecompressionMethods GZip   using  HttpWebResponse response    HttpWebResponse request GetResponse    using  Stream stream   response GetResponseStream    using  StreamReader reader   new StreamReader stream         html   reader ReadToEnd       Console WriteLine html     GET public string Get string uri        HttpWebRequest request    HttpWebRequest WebRequest Create uri       request AutomaticDecompression   DecompressionMethods GZip   DecompressionMethods Deflate       using HttpWebResponse response    HttpWebResponse request GetResponse        using Stream stream   response GetResponseStream        using StreamReader reader   new StreamReader stream                 return reader ReadToEnd              GET async public async Task lt string gt  GetAsync string uri        HttpWebRequest request    HttpWebRequest WebRequest Create uri       request AutomaticDecompression   DecompressionMethods GZip   DecompressionMethods Deflate       using HttpWebResponse response    HttpWebResponse await request GetResponseAsync        using Stream stream   response GetResponseStream        using StreamReader reader   new StreamReader stream                 return await reader ReadToEndAsync              POST Contains the parameter method in the event you wish to use other HTTP methods such as PUT  DELETE  ETC public string Post string uri  string data  string contentType  string method    quot POST quot         byte   dataBytes   Encoding UTF8 GetBytes data        HttpWebRequest request    HttpWebRequest WebRequest Create uri       request AutomaticDecompression   DecompressionMethods GZip   DecompressionMethods Deflate      request ContentLength   dataBytes Length      request ContentType   contentType      request Method   method       using Stream requestBody   request GetRequestStream                  requestBody Write dataBytes  0  dataBytes Length              using HttpWebResponse response    HttpWebResponse request GetResponse        using Stream stream   response GetResponseStream        using StreamReader reader   new StreamReader stream                 return reader ReadToEnd                    POST async Contains the parameter method in the event you wish to use other HTTP methods such as PUT  DELETE  ETC public async Task lt string gt  PostAsync string uri  string data  string contentType  string method    quot POST quot         byte   dataBytes   Encoding UTF8 GetBytes data        HttpWebRequest request    HttpWebRequest WebRequest Create uri       request AutomaticDecompression   DecompressionMethods GZip   DecompressionMethods Deflate      request ContentLength   dataBytes Length      request ContentType   contentType      request Method   method       using Stream requestBody   request GetRequestStream                  await requestBody WriteAsync dataBytes  0  dataBytes Length              using HttpWebResponse response    HttpWebResponse await request GetResponseAsync        using Stream stream   response GetResponseStream        using StreamReader reader   new StreamReader stream                 return await reader ReadToEndAsync

User · Answer

Adding to the responses already given  this is a complete example hitting JSON PlaceHolder site  using System  using System Net Http  using System Threading Tasks  using Newtonsoft Json   namespace Publish       class Program               static async Task Main string   args                                        Get Reqeust             HttpClient req   new HttpClient                var content   await req GetAsync  quot https   jsonplaceholder typicode com users quot                Console WriteLine await content Content ReadAsStringAsync                     Post Request             Post p   new Post  quot Some title quot    quot Some body quot    quot 1 quot                HttpContent payload   new StringContent JsonConvert SerializeObject p                content   await req PostAsync  quot https   jsonplaceholder typicode com posts quot   payload               Console WriteLine  quot -------------------------- quot                Console WriteLine content StatusCode               Console WriteLine await content Content ReadAsStringAsync                          public struct Post           public string Title  get  set           public string Body  get set           public string UserID  get  set            public Post string Title  string Body  string UserID               this Title   Title              this Body   Body              this UserID   UserID

User · Answer

Another way is using  HttpClient  like this  using System  using System Net  using System Net Http   namespace Test       class Program               static void Main string   args                        Console WriteLine  quot Making API Call    quot                using  var client   new HttpClient new HttpClientHandler   AutomaticDecompression   DecompressionMethods GZip   DecompressionMethods Deflate                                   client BaseAddress   new Uri  quot https   api stackexchange com 2 2  quot                    HttpResponseMessage response   client GetAsync  quot answers order desc amp sort activity amp site stackoverflow quot   Result                  response EnsureSuccessStatusCode                    string result   response Content ReadAsStringAsync   Result                  Console WriteLine  quot Result   quot    result                             Console ReadLine                       Check HttpClient vs HttpWebRequest from stackoverflow and this from other  Update June 22  2020  It s not recommended to use  httpclient in a  using  block as it might cause port exhaustion  private static HttpClient client   null       ContructorMethod        if client    null               HttpClientHandler handler   new HttpClientHandler                         AutomaticDecompression   DecompressionMethods GZip   DecompressionMethods Deflate                            client   new HttpClient handler           client BaseAddress   new Uri  quot https   api stackexchange com 2 2  quot       HttpResponseMessage response   client GetAsync  quot answers order desc amp sort activity amp site stackoverflow quot   Result     response EnsureSuccessStatusCode       string result   response Content ReadAsStringAsync   Result              Console WriteLine  quot Result   quot    result                  If using  Net Core 2 1   consider using IHttpClientFactory and injecting like this in your startup code   var timeout   Policy TimeoutAsync lt HttpResponseMessage gt               TimeSpan FromSeconds 60      services AddHttpClient lt XApiClient gt    ConfigurePrimaryHttpMessageHandler      gt  new HttpClientHandler                       AutomaticDecompression   DecompressionMethods GZip   DecompressionMethods Deflate            AddPolicyHandler request   gt  timeout

User · Answer

Simpliest way for my opinion    var web   new WebClient      var url      hostname  LoadDataSync systemID  systemId      var responseString   web DownloadString url     OR   var bytes   web DownloadData url

[c#] How to properly make a http web GET request

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