C# '；指定的强制转换无效'；调用SQL Server存储过程时出错

我使用以下代码调用SQL Server数据库中的存储过程

其思想是将相关事件添加到一个列表中，该列表是

EventSchedule

模型的一个属性，但代码返回一个

指定的强制转换无效

错误。存储过程从我构建的视图中提取数据。调用堆栈显示错误在第96行，不确定这是否对任何人都有帮助。我想我可能需要另一双眼睛来看看我在这里错过了什么

var command = new SqlCommand("GetEvents", conn)
{
    CommandType = CommandType.StoredProcedure
};

command.Parameters.Add(new SqlParameter("Id", SqlDbType.BigInt, 0, "id"));
command.Parameters[0].Value = schedule.LeagueId;

using (var reader = command.ExecuteReader())
{
    while (reader.Read())
    {
        //line 96
        var _event = new Event
        {
            EventId = (Int64) reader["eventid"],
            HomeTeamId = (Int64) reader["home_team_id"],
            TeamName = (string) reader["team_name"],
            HomeTeamScore = (int) reader["home_team_score"],
            AwayTeamId = (Int64) reader["away_team_id"],
            AwayTeamName = (string) reader["Expr1"],
            AwayTeamScore = (int) reader["away_team_score"],
            WinningTeamId = (Int64) reader["winning_teamid"],
            EventStartDttm = (DateTime) reader["event_start_dttm"],
            CurrentDttm = (DateTime) reader["current_dttm"],
            Locked = (bool) reader["locked"]
        };

        schedule.Events.Add(_event);
    }
}

return schedule;

型号：

public class EventSchedule
{
    public Int64 UserId { get; set; }
    public Int64 LeagueId { get; set; }
    public string League { get; set; }
    public int Season { get; set; }
    public int Week { get; set; }
    public IList<Event> Events { get; set; }
}

public class Event
{
    public Int64 EventId { get; set; }
    public Int64 HomeTeamId { get; set; }
    public string TeamName { get; set; }
    public int? HomeTeamScore { get; set; }
    public Int64 AwayTeamId { get; set; }
    public string AwayTeamName { get; set; }
    public int? AwayTeamScore { get; set; }
    public Int64 WinningTeamId { get; set; }
    public DateTime EventStartDttm { get; set; }
    public DateTime CurrentDttm { get; set; }
    public bool Locked { get; set; }
}

---

您的问题来自这样一个事实：您的一个强制转换失败，很可能是模型中的一个可为空类型。对于可为null的类型，从强制转换更改为使用

作为

，这将导致

DbNull.Value

（读取器返回的内容）成为所需的null值

    var _event = new Event
    {
        EventId = (Int64) reader["eventid"],
        HomeTeamId = (Int64) reader["home_team_id"],
        TeamName = (string) reader["team_name"],
        HomeTeamScore = reader["home_team_score"] as int?, //here
        AwayTeamId = (Int64) reader["away_team_id"],
        AwayTeamName = (string) reader["Expr1"],
        AwayTeamScore = reader["away_team_score"] as int?, //and here
        WinningTeamId = (Int64) reader["winning_teamid"],
        EventStartDttm = (DateTime) reader["event_start_dttm"],
        CurrentDttm = (DateTime) reader["current_dttm"],
        Locked = (bool) reader["locked"]
    };

如果问题仍然存在，则模型与数据表不匹配。你需要仔细检查你的类型，找出哪一个不匹配。你可以通过从构造器中分配任务来让自己更轻松

    var _event = new Event();

    _event.EventId = (Int64) reader["eventid"];
    _event.HomeTeamId = (Int64) reader["home_team_id"];
    _event.TeamName = (string) reader["team_name"];
    _event.HomeTeamScore = reader["home_team_score"] as int?;
    _event.AwayTeamId = (Int64) reader["away_team_id"];
    _event.AwayTeamName = (string) reader["Expr1"];
    _event.AwayTeamScore = reader["away_team_score"] as int?;
    _event.WinningTeamId = (Int64) reader["winning_teamid"];
    _event.EventStartDttm = (DateTime) reader["event_start_dttm"];
    _event.CurrentDttm = (DateTime) reader["current_dttm"];
    _event.Locked = (bool) reader["locked"];

---

sp返回的字段的数据类型是什么？我打赌某些字段可以为null，并且返回null。将

LeaguesScheduleforCurrentWeek

表/视图的ddl发布，而不是在构造函数中构建

事件

类，只需构造空事件，然后分别执行每一行

\u event.EventId=（Int64）reader[“EventId”]以查看错误所在的位置。您的问题源于您的一个强制转换失败。像
（Int64）reader[“eventid”]
这样的强制转换之一失败。在调试器中进行检查，或将属性分配分解为单独的语句，以确定是哪一个。这是我问题的确切解决方案。甚至不是存储过程，为什么我不记得为？。。。非常感谢。
    var _event = new Event();

    _event.EventId = (Int64) reader["eventid"];
    _event.HomeTeamId = (Int64) reader["home_team_id"];
    _event.TeamName = (string) reader["team_name"];
    _event.HomeTeamScore = reader["home_team_score"] as int?;
    _event.AwayTeamId = (Int64) reader["away_team_id"];
    _event.AwayTeamName = (string) reader["Expr1"];
    _event.AwayTeamScore = reader["away_team_score"] as int?;
    _event.WinningTeamId = (Int64) reader["winning_teamid"];
    _event.EventStartDttm = (DateTime) reader["event_start_dttm"];
    _event.CurrentDttm = (DateTime) reader["current_dttm"];
    _event.Locked = (bool) reader["locked"];