HttpClient client = new HttpClient();

var content = new FormUrlEncodedContent(new Dictionary<string, string>() {

{ "number", "09129457000" }

});

client.DefaultRequestHeaders.Referrer = new Uri("http://sim.mci.ir/first-step");

var resp = await client.PostAsync("http://sim.mci.ir/chk-number-availability", content);

var repsStr = await resp.Content.ReadAsStringAsync();

 

 

async Task<string> GetResponseString(string text)

{

var httpClient = new HttpClient();

var parameters = new Dictionary<string, string>();

parameters["text"] = text;

var response = await httpClient.PostAsync(BaseUri, new FormUrlEncodedContent(parameters));

var contents = await response.Content.ReadAsStringAsync();

return contents;

}

And your final function call:

Task<string> result = GetResponseString(text);

var finalResult = result.Result;

Or even better:

var finalResult = await GetResponseString(text);

 

//var httpClient = new HttpClient();

//string responseJson = httpClient.GetAsync(string.Format("", Phone, Message))

// .Result.Content.ReadAsStringAsync().Result;

var url = "";

var postData = new Dictionary<string, string>

{

{ "cdkey", "" },

{ "password", "" },

{"phone" ,""},

{"message" ,""}

};

var urlEncodedContent = new FormUrlEncodedContent(postData);

var httpClient = new HttpClient();

var result = httpClient.PostAsync(url, urlEncodedContent).Result.Content.ReadAsStringAsync().Result;