在C#中将记录插入表时无法将NULL值传递给参数

参见英文答案 > The parameterized query expects the parameter which was not supplied????????????????????????????????????6个
我正在尝试构建一些查询并使用C#将包含7列的列表插入到SQL表中.
在我的列表中,我有几列的NULL值,我无法将它们传递给以下查询

string strInsertListToTable = @"INSERT INTO ImpliedOutrightData (id,product,term,bid,offer,bidcp,offercp) VALUES(@id,@product,@term,@bid,@offer,@bidcp,@offercp)";
    for (int i = 0; i < resultList.Count; i++)
        {  


           SqlCommand cmdInsertList = new SqlCommand(strInsertListToTable,sqlcon);

            cmdInsertList.CommandType = CommandType.Text;
            cmdInsertList.Parameters.Clear();
            cmdInsertList.Parameters.AddWithValue("@id",resultList[i].id);
            cmdInsertList.Parameters.AddWithValue("@product",resultList[i].product);
            cmdInsertList.Parameters.AddWithValue("@term",resultList[i].term);
            cmdInsertList.Parameters.AddWithValue("@bid",resultList[i].bid);
            cmdInsertList.Parameters.AddWithValue("@offer",resultList[i].offer);

            cmdInsertList.Parameters.AddWithValue("@bidcp",resultList[i].bidcp);
            cmdInsertList.Parameters.AddWithValue("@offercp",resultList[i].offercp);
            cmdInsertList.ExecuteNonQuery();
        }

虽然上面的查询循环我得到错误

The parameterized query '(@id int,@product nvarchar(2),@term nvarchar(5),@bid float,@bidc' expects the parameter '@offercp',which was not supplied.

cmdInsertList.Parameters.AddWithValue(
    "@offercp",resultList[i].offercp == null ? (object)DbNull.Value : resultList[i].offercp
);