C# - 如何将SQL Server时间(7)检索到TimeSpan中

Question

我试图了解如何从定义为的SQL Server 2012表列中检索时间数据Time(7).我到处寻找,并为此而苦苦挣扎.这里有一些简单的代码,我只是试图让它工作.你能帮我么？？

当下面的代码运行时(使用Visual Studio 2013),我得到了错误TimeSpan DBStartTime...:

无法将类型为"System.TimeSpan"的对象强制转换为"System.IConvertible".

我不知道如何解决这个问题.

var cnnString = ConfigurationManager.ConnectionStrings["TaktBoardsConnectionString"].ConnectionString;
SqlConnection conn = new SqlConnection(cnnString); 

SqlCommand comm = new SqlCommand();
comm.CommandText = "SELECT * FROM ScheduleDetail WHERE ScheduleID = " + lstShifts.SelectedValue;
comm.CommandType = CommandType.Text;
comm.Connection = conn;

SqlDataReader reader;

conn.Open();
reader = comm.ExecuteReader(); 

while (reader.Read())
{
    TimeSpan DBStartTime = Convert.ToDateTime(reader["StartTime"]).TimeOfDay;
    TimeSpan DBEndTime = Convert.ToDateTime(reader["EndTime"]).TimeOfDay;

    // Add more coding once this works.
}

conn.Close();

Answer 1

不要使用Convert.ToDateTime读者已经返回Timespan,只需做直接演员.

    TimeSpan DBStartTime = (TimeSpan)reader["StartTime"];
    TimeSpan DBEndTime = (TimeSpan)reader["EndTime"];

此外,与您的问题无关,但您没有使用参数ScheduleID = " + lstShifts.SelectedValue;,您真的应该.using当你的代码确实抛出异常而你没有关闭连接对象时,你也没有使用语句.

var cnnString = ConfigurationManager.ConnectionStrings["TaktBoardsConnectionString"].ConnectionString;
using(SqlConnection conn = new SqlConnection(cnnString))
using(SqlCommand comm = new SqlCommand())
{
    comm.CommandText = "SELECT * FROM ScheduleDetail WHERE ScheduleID = @ScheduleID";
    comm.Parameters.Add("@ScheduleID", SqlDbType.Int).Value = lstShifts.SelectedValue;
    comm.CommandType = CommandType.Text;
    comm.Connection = conn;

    conn.Open();

    using(SqlDataReader reader = comm.ExecuteReader())
    {
        while (reader.Read())
        {
             TimeSpan DBStartTime = (TimeSpan)reader["StartTime"];
             TimeSpan DBEndTime = (TimeSpan)reader["EndTime"];
            // Add more coding once this works.
        }
    }
}