c# - 无法等待系统集合通用可枚举

Question

我对异步编程非常陌生，我被要求在不破坏现有功能的情况下实现异步。 在我的 Web API 服务层中，我有这样的内容:

public IList<Entities.Case.CreateCaseOutput> createCase(ARC.Donor.Data.Entities.Case.CreateCaseInput CreateCaseInput, ARC.Donor.Data.Entities.Case.SaveCaseSearchInput SaveCaseSearchInput)
{
    Repository rep = new Repository();
    string RequestType = "Insert";
    string strSPQuery = string.Empty;
    List<object> listParam = new List<object>();
    SQL.CaseSQL.getCreateCaseParameters(CreateCaseInput, RequestType, out strSPQuery, out listParam);
    var AcctLst = rep.ExecuteStoredProcedure<Entities.Case.CreateCaseOutput>(strSPQuery, listParam).ToList();
    if (!string.IsNullOrEmpty(AcctLst.ElementAt(0).o_case_seq.ToString()))
        saveCaseSearch(SaveCaseSearchInput, AcctLst.ElementAt(0).o_case_seq);
    return AcctLst;
}

这个 SaveCaseSearch 是异步实现的:

public async Task<IList<Entities.Case.SaveCaseSearchOutput>> saveCaseSearch(ARC.Donor.Data.Entities.Case.SaveCaseSearchInput SaveCaseSearchInput,Int64? case_key)
{
    Repository rep = new Repository();
    string strSPQuery = string.Empty;
    List<object> listParam = new List<object>();
    SQL.CaseSQL.getSaveCaseSearchParameters(SaveCaseSearchInput, case_key,out strSPQuery, out listParam);
    var AcctLst = await rep.ExecuteStoredProcedure<Entities.Case.SaveCaseSearchOutput>(strSPQuery, listParam).ToList();
    return AcctLst;
}

但它说:

ExecuteStoredProcedure 看起来像:

public IEnumerable<T> ExecuteStoredProcedure<T>(string strSPQuery, List<object> parameters)
{
    _msg = "";
    try
    {
        this._context.Database.CommandTimeout = 280;

        return this._context.Database.SqlQuery<T>(strSPQuery, parameters.ToArray());

    }
    catch (Exception ex)
    {
        _msg = "ERROR: " + ex.Message;
        if (ex.InnerException != null) { _msg += "INNER EXCEPTION: " + ex.InnerException; }
        log.Info(_msg);
    }
    return null;
}

可以做什么？ ToListAsync() 值得关注吗？当我尝试时，我得到了

并更改 ExecuteStoredProcedure 定义会产生

public Task<IEnumerable<T>> ExecuteStoredProcedure<T>(string strSPQuery, List<object> parameters)
{
    _msg = "";
    try
    {
        this._context.Database.CommandTimeout = 280;

        return this._context.Database.SqlQuery<T>(strSPQuery, parameters.ToArray());

    }
    catch (Exception ex)
    {
        _msg = "ERROR: " + ex.Message;
        if (ex.InnerException != null) { _msg += "INNER EXCEPTION: " + ex.InnerException; }
        log.Info(_msg);
    }
    return null;
}

错误:

错误 13 无法将类型“System.Data.Entity.Infrastruct.DbRawSqlQuery”隐式转换为“System.Threading.Tasks.Task>”C:\Users\m1034699\Desktop\Stuart_V2_12042016\Stuart Web Service\ARC .Donor.Data\Repository.cs 115 24 ARC.Donor.Data

我不知道该怎么做。请帮忙。

Answer 1

您必须使用异步版本的方法。

尝试:

var AcctLst = await rep.ExecuteStoredProcedure<Entities.Case.SaveCaseSearchOutput>(strSPQuery, listParam).ToListAsync();