NET MVC，循環中的異步任務

Question

我是新的異步編程在asp中，我有一個問題和問題。我想連接到外部API和我創建類任務，這裏是類的一個znippet

public class Tasks 
{ 
    HttpClient httpc = new HttpClient(); 

    public async System.Threading.Tasks.Task<String> getStations() 
    { 
     var uri = new Uri("http://api.gios.gov.pl/pjp-api/rest/station/findAll"); 
     var response = await httpc.GetAsync(uri); 
     return await response.Content.ReadAsStringAsync(); 
    } 

    public async System.Threading.Tasks.Task<String> getStationDetails(int id) 
    { 
     string path = "http://api.gios.gov.pl/pjp-api/rest/station/sensors/" + id; 
     var uri = new Uri(path); 
     var response = await httpc.GetAsync(uri); 
     return await response.Content.ReadAsStringAsync(); 
    } 

    public async System.Threading.Tasks.Task<String> getStationValues(int id) 
    { 
     string path = "http://api.gios.gov.pl/pjp-api/rest/data/getData/" + id; 
     var uri = new Uri(path); 
     var response = await httpc.GetAsync(uri); 
     return await response.Content.ReadAsStringAsync(); 
    } 

然後我爲我的請求，其中，i準備數據以響應

 public async Task<ActionResult> prepareAirContitionData(int id) 
    { 
     Task<string> taskStationDetails = tasks.getStationDetails(id); 
     string stationDetail = await taskStationDetails; 

     List<Station> stationsObj = JsonConvert.DeserializeObject<List<Station>>(stationDetail); 

     List<Task<string>> stationsValues = new List<Task<string>>(); 
     foreach(var station in stationsObj) 
     { 
      stationsValues.Add(tasks.getStationValues(station.stationId)); 
     } 

     string[] war = await Task.WhenAll(stationsValues.ToArray()); 
     Console.Write(war); 
     return Json("", JsonRequestBehavior.AllowGet); 
    } 

創建asyncronous控制器這是我的任務草案。問題出現在循環中，當我收集任務並等待它時，它們不顯示在我的字符串數組中，只填充一個變量。

Answer 1

看樣子你打了同樣的問題，因爲這等SO question

你需要傳回所提取的響應