如何使這個異步控制器方法？

Question

我有一個方法

public void AddOrUpdateAnswer (AnswerSubmission Answer, Guid pid) 
    { 
     this._Conn.Open(); 
     using (SqlCommand cmd = new SqlCommand("AddOrUpdateAnswer", this._Conn)) 
     { 
      cmd.CommandType = CommandType.StoredProcedure; 
      cmd.Parameters.AddWithValue("@AnswerVal", Answer.AnswerVal); 
      cmd.Parameters.AddWithValue("@QuestionId", Answer.QuestionId); 
      cmd.Parameters.AddWithValue("@PartnerId", pid); 
      cmd.ExecuteNonQuery(); 
     } 
     this._Conn.Close(); 
    } 

，我需要轉換成一個異步任務，因爲我發現它被撞毀我的web應用程序（502網關錯誤），每當我在有一個以上的用戶主動提交答案時間。所以我知道我需要做的是讓這個人成爲一個異步方法。目前，它就會由我控制像

[HttpPost] 
    public ActionResult SubmitAnswer (AnswerSubmission Answer, Guid pid) 
    { 
     bool goodSoFar = true; 
     string status = "Answers submitted successfully"; 
     try 
     { 
      this._Db.AddOrUpdateAnswer(Answer, pid); 
     } 
     catch (Exception e) 
     { 
      goodSoFar = false; 
      status = String.Format("Exception occured during answer submission: {0}", e.Message); 
     } 
     return Json(new { Succeeded = goodSoFar, Message = status }); 
    } 

所謂我認爲我需要做的是使該 像

[HttpPost] 
    public async Task<ActionResult> SubmitAnswer (AnswerSubmission Answer, Guid pid) 
    { 
     bool goodSoFar = true; 
     string status = "Answers submitted successfully"; 
     try 
     { 
      await this._Db.AddOrUpdateAnswer(Answer, pid); 
     } 
     catch (Exception e) 
     { 
      goodSoFar = false; 
      status = String.Format("Exception occured during answer submission: {0}", e.Message); 
     } 
     return Json(new { Succeeded = goodSoFar, Message = status }); 
    } 

但後來我該怎麼辦與AddOrUpdateAnswer？我試圖將其更改爲

public Task AddOrUpdateAnswer

但後來我得到了，並不是所有的路徑返回一個值的誤差。我應該回來什麼？

Answer 1

你只需要你的方法轉換爲異步：

public async Task AddOrUpdateAnswerAsync (AnswerSubmission Answer, Guid pid) 
    { 
     await this._Conn.OpenAsync(); 
     using (SqlCommand cmd = new SqlCommand("AddOrUpdateAnswer", this._Conn)) 
     { 
      cmd.CommandType = CommandType.StoredProcedure; 
      cmd.Parameters.AddWithValue("@AnswerVal", Answer.AnswerVal); 
      cmd.Parameters.AddWithValue("@QuestionId", Answer.QuestionId); 
      cmd.Parameters.AddWithValue("@PartnerId", pid); 
      await cmd.ExecuteNonQueryAsync(); 
     } 
     this._Conn.Close(); 
    } 

有更多的細節來看看here