How to POST using HTTPclient content type = application/x-www-form-urlencoded

I am currently developing a wp8.1 application C#, i have managed to perform a POST method in json to my api by creating a json object (bm) from textbox.texts. here is my code below. How do i take the same textbox.text and POST them as a content type = application/x-www-form-urlencoded. whats the code for that?

Profile bm = new Profile();
bm.first_name = Names.Text;
bm.surname = surname.Text;

string json = JsonConvert.SerializeObject(bm);

MessageDialog messageDialog = new MessageDialog(json);//Text should not be empty 
await messageDialog.ShowAsync();

HttpClient client = new HttpClient();
client.DefaultRequestHeaders.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "application/json");

byte[] messageBytes = Encoding.UTF8.GetBytes(json);
var content = new ByteArrayContent(messageBytes);
content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
var response = client.PostAsync("myapiurl", content).Result;

Solution 1:

var nvc = new List<KeyValuePair<string, string>>();
nvc.Add(new KeyValuePair<string, string>("Input1", "TEST2"));
nvc.Add(new KeyValuePair<string, string>("Input2", "TEST2"));
var client = new HttpClient();
var req = new HttpRequestMessage(HttpMethod.Post, url) { Content = new FormUrlEncodedContent(nvc) };
var res = await client.SendAsync(req);

Or

var dict = new Dictionary<string, string>();
dict.Add("Input1", "TEST2");
dict.Add("Input2", "TEST2");
var client = new HttpClient();
var req = new HttpRequestMessage(HttpMethod.Post, url) { Content = new FormUrlEncodedContent(dict) };
var res = await client.SendAsync(req);

Solution 2:

 var params= new Dictionary<string, string>();
 var url ="Please enter URLhere"; 
 params.Add("key1", "value1");
 params.Add("key2", "value2");
             
 using (HttpClient client = new HttpClient())
 {
    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

    HttpResponseMessage response = client.PostAsync(url, new FormUrlEncodedContent(params)).Result;
    var token = response.Content.ReadAsStringAsync().Result;
}
               
//Get response as expected

Solution 3:

The best solution for me is:

// Add key/value
var dict = new Dictionary<string, string>();
dict.Add("Content-Type", "application/x-www-form-urlencoded");

// Execute post method
using (var response = httpClient.PostAsync(path, new FormUrlEncodedContent(dict))){}