Question

使用C＃中的API调用非常陌生（一般来说，这是C＃的第三天）。

我创建了下面的代码，只是弄湿了我的脚，但无论如何我都无法弄清楚是否返回标有“ token”的字符串。

在以后的工作中，我需要在Main中使用它。我了解或相信我了解的事情：

GetToken由于void而无法返回值。
由于GetToken方法仅是string或返回void，因此无法将async更改为void而不是Task。

任何帮助表示赞赏。

class Program {
  static void Main(string[] args) {
    string baseURL = "xxxxx";
    string UserName = "xxxx";
    string Password = "xxxxx";
    string api_key = "xxxxx";
    string api_token = "";
    GetToken(baseURL, UserName, Password, api_key);
  }
  async static string GetToken(string url, string username, string password, string apikey) {
    using (HttpClient client = new HttpClient()) {
      TokenRequestor tokenRequest = new TokenRequestor(apikey, username, password);
      string JSONresult = JsonConvert.SerializeObject(tokenRequest);
      HttpContent c = new StringContent(JSONresult, Encoding.UTF8, "application/json");
      HttpResponseMessage message = await client.PostAsync(url, c);
      string tokenJSON = await message.Content.ReadAsStringAsync();
      string pattern = "token\":\"([a-z0-9]*)";
      Regex myRegex = new Regex(pattern, RegexOptions.IgnoreCase);
      Match m = myRegex.Match(tokenJSON);
      String string_m = m.ToString();
      char[] chars = { ':' };
      string[] matches = string_m.Split(chars);
      string final_match = matches[1].Trim(new Char[] { '"' });
      string token = final_match;
    }
  }
}
public class TokenRequestor {
  public string method;
  public string module;
  public string key;
  public RequestMaker request;
  public TokenRequestor(string apikey, string Name, string pwd) {
    method = "get";
    module = "api.login";
    key = apikey;
    request = new RequestMaker(Name, pwd);
  }
}
public class RequestMaker {
  public string username;
  public string password;
  public RequestMaker(string uname, string pwd) {
    username = uname;
    password = pwd;
  }
}

Answer 1

将GetToken()方法的返回类型从void更改为Task<string>。然后，您可以从token

返回字符串GetToken()

此外，您的Main方法签名需要更改为static async Task Main(string[] args)，以便您可以按以下方式调用等待的GetToken()：

string token = await GetToken(baseURL, UserName, Password, api_key);来自您的Main

using Newtonsoft.Json;
using System;
using System.Net.Http;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

public class Program
{
        static async Task Main(string[] args)
        {
            string baseURL = "xxxxx";
            string UserName = "xxxx";
            string Password = "xxxxx";
            string api_key = "xxxxx";
            string api_token = "";

            string token = await GetToken(baseURL, UserName, Password, api_key);
        }

        static async Task<string> GetToken(string url, string username, string password, string apikey)
        {
            string token = string.Empty;

            using (HttpClient client = new HttpClient())
            {
                TokenRequestor tokenRequest = new TokenRequestor(apikey, username, password);
                string JSONresult = JsonConvert.SerializeObject(tokenRequest);
                HttpContent c = new StringContent(JSONresult, Encoding.UTF8, "application/json");
                HttpResponseMessage message = await client.PostAsync(url, c);    
                string tokenJSON = await message.Content.ReadAsStringAsync();   
                string pattern = "token\":\"([a-z0-9]*)";
                Regex myRegex = new Regex(pattern, RegexOptions.IgnoreCase);
                Match m = myRegex.Match(tokenJSON);
                String string_m = m.ToString();
                char[] chars = { ':' };
                string[] matches = string_m.Split(chars);
                string final_match = matches[1].Trim(new Char[] { '"' });
                token = final_match;
            }

            return token;
        }            
}

public class TokenRequestor
{

    public string method;
    public string module;
    public string key;
    public RequestMaker request;

    public TokenRequestor(string apikey, string Name, string pwd)
    {
        method = "get";
        module = "api.login";
        key = apikey;
        request = new RequestMaker(Name, pwd);
    }


}

public class RequestMaker
{
    public string username;
    public string password;

    public RequestMaker(string uname, string pwd)
    {
        username = uname;
        password = pwd;

    }        
}

Answer 2

async static string GetToken(string url, string username, string password, string apikey)

应该是

async static Task<String> GetToken(...)

返回异步任务中的值（“方法”）

Answer 3

NGambits的答案很好，尽管在这种情况下，我能够完全放弃异步并使用message.Content.ReadAsStringAsync（）。Result来返回我需要的值。

  static string GetToken(string url, string username, string password, string apikey)
    {

        using (HttpClient client = new HttpClient())
        {


            TokenRequestor tokenRequest = new TokenRequestor(apikey, username, password);

            string JSONresult = JsonConvert.SerializeObject(tokenRequest);

            HttpContent c = new StringContent(JSONresult, Encoding.UTF8, "application/json");

            //Console.WriteLine(JSONresult);

            HttpResponseMessage message =  client.PostAsync(url, c).Result;
            // Console.WriteLine(await message.Content.ReadAsStringAsync());
            string tokenJSON =  message.Content.ReadAsStringAsync().Result;

            string pattern = "token\":\"([a-z0-9]*)";
            Regex myRegex = new Regex(pattern, RegexOptions.IgnoreCase);
            Match m = myRegex.Match(tokenJSON);
            String string_m = m.ToString();
            char[] chars = { ':' };
            string[] matches = string_m.Split(chars);
            string final_match = matches[1].Trim(new Char[] { '"' });
            string token = final_match;

            Console.WriteLine(token); //just for testing purposes to make sure i'm getting the data I want. 

            return token;

        }
    }

从API发布返回字符串

3 个答案: