title: Replace WebClient.UploadString() to HttpClient.PostAsync
body: <p>I want to replace WebClient to HttpClient in my code. What HttpContent I have to use in HttpClient to replace WebClient.UploadString?
  My WebClient code:</p>
  
  <pre><code>string data = string.Format("name={0}&amp;warehouse={1}&amp;address={2}", name, shop.Warehouse.Id, shop.Address);
  
  using (var wc = new WebClient()) {
      wc.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
      wc.Encoding = Encoding.UTF8;
  
      string fullUrl = BaseUrl + url;
      string response = wc.UploadString(fullUrl, data);
      // ...
  }
  </code></pre>