class Program
{
static void Main(string[] args)
{
string _address = "http://api.worldbank.org/countries?format=json";
// Create an HttpClient instance 
HttpClient client = new HttpClient();

//远程获取数据
var task = client.GetAsync(_address);
var rep = task.Result;//在这里会等待task返回。

//读取响应内容
var task2 = rep.Content.ReadAsStringAsync();
var ret = task2.Result;//在这里会等待task返回。
Console.WriteLine(ret);

Console.WriteLine("Hit ENTER to exit...");
Console.ReadLine();
}
}

HttpClient httpClient = new HttpClient();
string url = "******";
HttpResponseMessage response = await httpClient.PostAsync(url, null);
response.EnsureSuccessStatusCode();
string resultStr = await response.Content.ReadAsStringAsync();
var dev = JsonConvert.DeserializeObject<List<实体类名>>(resultStr);

private async void HttpPost() {
HttpClient httpClient = new HttpClient();

var data = new Dictionary<string, string>();
data["username"] = "cs_admin";
data["password"] = "cs_12345";
var content = new FormUrlEncodedContent(data);

string url = "http://localhost:8080/server-http/http/emulator/post";
HttpResponseMessage response = await httpClient.PostAsync(url, content);
response.EnsureSuccessStatusCode();
string resultStr = await response.Content.ReadAsStringAsync();
Console.WriteLine(resultStr);
}