Many times in application development using C# it is required to to post some data to a specific URL. In this article I will show two options for implementing this :

1) Using WebClient

 string url = "http://www.url.com/post.aspx";
string params = "param1=value1&param2=value2";

using (WebClient wc = new WebClient())
{
    wc.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
    string HtmlResult = wc.UploadString(url, params);
}

2) Using HttpClient

using (var client = new HttpClient())
{
    var data = new Dictionary<string, string>
    {
       { "key1", "value1" },
       { "key2", "value2" }
    };

    var content = new FormUrlEncodedContent(data);

    var response = await client.PostAsync("http://www.url.com/post.aspx", content);

    var responseString = await response.Content.ReadAsStringAsync();
}

Out of the two approaches shown above using the HttpClient is the preferred approach.