asp.net-mvc – ASP.NET MVC：自定义排序

这是我的表头：

<tr>
    <th>
        S.No.
    </th>
    <th>
        @Html.ActionLink("UrlTitle","Index",new { SortOrder = ViewBag.SortOrder == null ? "Asc" : (ViewBag.SortOrder == "Asc"? "Desc":"Asc"),SortBy = "UrlTitle" })
    </th>
    <th>
        @Html.DisplayNameFor(model => model.Url)
    </th>
    <th>
        @Html.DisplayNameFor(model => model.UrlDesc)
    </th>

    <th>
        @Html.DisplayNameFor(model => model.tbl_Category.CategoryName)
    </th>
</tr>

这就是行动：

public ActionResult Index(String SortOrder,String SortBy)
    {
        ViewBag.SortOrder = SortOrder;
        ViewBag.SortBy = SortBy;

        var model = ObjBs.GetAll().Where(x=>x.IsApproved == "A");
        switch(SortOrder)
        {
            case "Asc":
                model = model.OrderBy(x => x.UrlTitle);
                break;
            case "Desc":
                model = model.OrderByDescending(x => x.UrlTitle);
                break;
        }
        return View(model);
    }

目前,我可以按UrlTitle排序,它没有任何问题.但如果我也想按其他列排序,我写了这样的东西：

switch(SortBy)
        {
            case "UrlTitle":
                switch(SortOrder)
                {
                    case "Asc":
                        model = model.OrderBy(x => x.UrlTitle);
                        break;
                    case "Desc":
                        model = model.OrderByDescending(x => x.UrlTitle);
                        break;
                    default:
                        break;
                }
                break;

            case "Category":
                switch (SortOrder)
                {
                    case "Asc":
                        model = model.OrderBy(x => x.UrlTitle);
                        break;
                    case "Desc":
                        model = model.OrderByDescending(x => x.UrlTitle);
                        break;
                    default:
                        break;
                }
                break;

            case "URL":
                switch (SortOrder)
                {
                    case "Asc":
                        model = model.OrderBy(x => x.UrlTitle);
                        break;
                    case "Desc":
                        model = model.OrderByDescending(x => x.UrlTitle);
                        break;
                    default:
                        break;
                }
                break;

            default:
                break;
        }

因为我可以通过参数传递列名,而不是编写嵌套开关,所以我不能这样做：

model = model.OrderBy(x => x.SortBy); Or,model = model.OrderBy(SortBy);

好吧,我认为当程序运行时,SortBy的值将是columnName.但它似乎不起作用.

我只是不想反复写相似的代码.如何最小化它或使其更好？