在C#中通过POST发送JSON并接收返回的JSON？

这是我第一次使用 JSON 以及System.Net和WebRequest在我的任何应用程序中。我的应用程序应该向身份验证服务器发送一个 JSON 负载，类似于下面的负载：

{
  "agent": {                             
    "name": "Agent Name",                
    "version": 1                                                          
  },
  "username": "Username",                                   
  "password": "User Password",
  "token": "xxxxxx"
}

为了创建这个有效负载，我使用了JSON.NET图书馆。我如何将此数据发送到身份验证服务器并接收其 JSON 响应？以下是我在一些示例中看到的内容，但没有 JSON 内容：

var http = (HttpWebRequest)WebRequest.Create(new Uri(baseUrl));
http.Accept = "application/json";
http.ContentType = "application/json";
http.Method = "POST";

string parsedContent = "Parsed JSON Content needs to go here";
ASCIIEncoding encoding = new ASCIIEncoding();
Byte[] bytes = encoding.GetBytes(parsedContent);

Stream newStream = http.GetRequestStream();
newStream.Write(bytes, 0, bytes.Length);
newStream.Close();

var response = http.GetResponse();

var stream = response.GetResponseStream();
var sr = new StreamReader(stream);
var content = sr.ReadToEnd();

然而，与我过去使用过的其他语言相比，这似乎是很多代码。我这样做正确吗？我如何获取 JSON 响应以便我可以解析它？

谢谢，精英。

更新代码

// Send the POST Request to the Authentication Server
// Error Here
string json = await Task.Run(() => JsonConvert.SerializeObject(createLoginPayload(usernameTextBox.Text, password)));
var httpContent = new StringContent(json, Encoding.UTF8, "application/json");
using (var httpClient = new HttpClient())
{
    // Error here
    var httpResponse = await httpClient.PostAsync("URL HERE", httpContent);
    if (httpResponse.Content != null)
    {
        // Error Here
        var responseContent = await httpResponse.Content.ReadAsStringAsync();
    }
}

我发现自己使用Http客户端用于查询 RESTful API 的库，因为代码非常简单且完全异步。要发送此 JSON 负载：

{
  "agent": {                             
    "name": "Agent Name",                
    "version": 1                                                          
  },
  "username": "Username",                                   
  "password": "User Password",
  "token": "xxxxxx"
}

有两个类代表您发布的 JSON 结构，可能如下所示：

public class Credentials
{
    public Agent Agent { get; set; }
    
    public string Username { get; set; }
    
    public string Password { get; set; }
    
    public string Token { get; set; }
}

public class Agent
{
    public string Name { get; set; }
    
    public int Version { get; set; }
}

您可以使用这样的方法来执行您的 POST 请求：

var payload = new Credentials { 
    Agent = new Agent { 
        Name = "Agent Name",
        Version = 1 
    },
    Username = "Username",
    Password = "User Password",
    Token = "xxxxx"
};

// Serialize our concrete class into a JSON String
var stringPayload = JsonConvert.SerializeObject(payload);

// Wrap our JSON inside a StringContent which then can be used by the HttpClient class
var httpContent = new StringContent(stringPayload, Encoding.UTF8, "application/json");

var httpClient = new HttpClient()
    
// Do the actual request and await the response
var httpResponse = await httpClient.PostAsync("http://localhost/api/path", httpContent);

// If the response contains content we want to read it!
if (httpResponse.Content != null) {
    var responseContent = await httpResponse.Content.ReadAsStringAsync();
    
    // From here on you could deserialize the ResponseContent back again to a concrete C# type using Json.Net
}