錯誤「設備」不包含在controlller MVC

在接下來的代碼爲「GetAwaiter」的定義錯誤「設備」不包含在controlller MVC

[HttpPost] 
    [ValidateAntiForgeryToken] 
    public async Task<ActionResult> Create([Bind(Include = "DispositivoID,Nombre,ClaveDispositivo,Activo,EmpresaID")] Modelo.Dispositivo dispositivo) 
    { 
     if (ModelState.IsValid) 
     { 
      //string deviceId = "minwinpc"; 
      Device device; 
      try 
      { 
       device = await registryManager.AddDeviceAsync(new Device(dispositivo.Nombre)).Result; 

      } 
      catch (DeviceAlreadyExistsException) 
      { 
       device = await registryManager.GetDeviceAsync(dispositivo.Nombre).Result; 
      } 

      dispositivo.ClaveDispositivo = device.Authentication.SymmetricKey.PrimaryKey; 
      db.Dispositivos.Add(dispositivo); 
      db.SaveChanges(); 
      return RedirectToAction("Index"); 
     } 

     ViewBag.EmpresaID = new SelectList(db.Empresas, "EmpresaID", "Nombre", dispositivo.EmpresaID); 
     return View(dispositivo); 
    }

我有一個錯誤：

Error CS1061 'Device' does not contain a definition for 'GetAwaiter' and no extension method 'GetAwaiter' accepting a first argument of type 'Device' could be found (are you missing a using directive or an assembly reference?)

在「設備」有：

using System; 
using Microsoft.Azure.Devices.Common; 
using Newtonsoft.Json; 
using Newtonsoft.Json.Converters; 

namespace Microsoft.Azure.Devices 
{ 
public class Device : IETagHolder 
{ 
    public Device(); 
    public Device(string id); 

    [JsonProperty(PropertyName = "authentication")] 
    public AuthenticationMechanism Authentication { get; set; } 
    [JsonProperty(PropertyName = "cloudToDeviceMessageCount")] 
    public int CloudToDeviceMessageCount { get; } 
    [JsonConverter(typeof(StringEnumConverter))] 
    [JsonProperty(PropertyName = "connectionState")] 
    public DeviceConnectionState ConnectionState { get; } 
    [JsonProperty(PropertyName = "connectionStateUpdatedTime")] 
    public DateTime ConnectionStateUpdatedTime { get; } 
    [JsonProperty(PropertyName = "etag")] 
    public string ETag { get; set; } 
    [JsonProperty(PropertyName = "generationId")] 
    public string GenerationId { get; } 
    [JsonProperty(PropertyName = "deviceId")] 
    public string Id { get; } 
    [JsonProperty(PropertyName = "lastActivityTime")] 
    public DateTime LastActivityTime { get; } 
    [JsonConverter(typeof(StringEnumConverter))] 
    [JsonProperty(PropertyName = "status")] 
    public DeviceStatus Status { get; set; } 
    [JsonProperty(PropertyName = "statusReason")] 
    public string StatusReason { get; set; } 
    [JsonProperty(PropertyName = "statusUpdatedTime")] 
    public DateTime StatusUpdatedTime { get; } 
}

}

來源

2016-09-22 Yefferson Alvarez Zapata

你甲肝e等待異步方法返回的任務，而不是任務。結果。當使用await時，返回表達式的值將已經是task.Result屬性。

因此，在異步調用後刪除.Result，它應該可以正常工作。對於

try 
{ 
    device = await registryManager.AddDeviceAsync(new Device(dispositivo.Nombre)); 

} 
catch (DeviceAlreadyExistsException) 
{ 
    device = await registryManager.GetDeviceAsync(dispositivo.Nombre); 
}

來源

2016-09-22 19:02:32 fbiagi

要點Async-Await

只能await一個Task or Task<T>
await是強制性的製作方法Async，否則它就像一個同步方法
await自動解包價值，因此：

設備=等待<Task<Device> from Async call>

是完全正常的，將填補該設備對象的值，你不需要在Task

很重要的一點Result呼叫使用類似Task.Result或如果您打算刪除await並堅持使用Result來填充設備對象，則會在運行時導致Deadlock在運行時由於阻止Synchronization context而導致Task.Wait， n運行時問題，請檢查here

來源

2016-09-23 05:03:08

錯誤「設備」不包含在controlller MVC

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