当保存在Session中的对象，取出后，在外部发生改变时会怎样

            return_reason_model model = new return_reason_model();

            model.F_RetunrnReason = "";

            HttpContext.Session["Return"] = model;

            model.F_RetunrnReason = "";

            return_reason_model model2 = HttpContext.Session["Return"] as return_reason_model;

在上述代码中，model2.F_RetunrnReason=?? 答案是“2”

           int a = ;

            HttpContext.Session["Return"] = a;

            a = ;

            int b = (int)HttpContext.Session["Return"];

在上面代码中，b=?? 答案是1