如何使它成为异步控制器方法？

Question

我有一个方法

    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();
    }

我需要将其转换为异步任务，因为我发现每当我有多个用户一次主动提交答案时，它就会使我的 Web 应用程序 (502 Bad Gateway) 崩溃。所以我知道我需要做的就是让这个 who thing 成为一个异步方法。目前，它被我的控制器调用，如

    [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 });
    }

所以我认为我需要做的就是做到这一点 喜欢

    [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 });
    }

但是我该怎么处理AddOrUpdateAnswer？我尝试将其更改为

public Task AddOrUpdateAnswer

但后来我得到了不是所有路径都返回值的错误。我应该返回什么？

Answer 1

您只需要将您的方法转换为异步：

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();
    }

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