SqlTransaction 已完成;它再也無法使用解決方法

示例代碼：

       SqlServerDataBase obj = new SqlServerDataBase();
        SqlConnection conn = obj.DBconn();
        conn.Open();
        SqlTransaction myTrans;
        myTrans = conn.BeginTransaction(IsolationLevel.ReadCommitted);

        try
        {
            obj.Insert("insert into StuInfo (StuNumber,Name,Sex,Specialty) values('" + stuNumber + "','" + name + "','" + sex + "','" + specialty + "')", null);
            obj.Insert("insert into StuSkill(StuNumber,Skill) values('" + stuNumber + "','" + skill + "')", null);
            myTrans.Commit();
            Response.Write("兩條數據均插入到數據庫中！");
        }
        catch (Exception ex)
        {
            try
            {
                myTrans.Rollback();
            }
            catch (SqlException sqlEx)
            {
                if (obj.DBconn() != null)
                {
                    Response.Write(sqlEx.GetType(