asp.net-mvc - ASP.NET MVC : Custom Sorting

Question

我正在尝试在我的小型 asp.net mvc 应用程序中实现自定义排序。嗯，有很多可用的插件。但这次我想自己做。

这是我的表格标题:

 <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>

这就是操作:

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，没有问题。但是如果我也想按其他列排序，我写了这样的内容:

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;
        }

既然我可以通过参数传递列名，而不是编写嵌套开关，我不能做这样的事情吗:

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

嗯，我认为当程序运行时，SortBy 的值将是columnName。但这似乎不起作用。

我只是不想重复写类似的代码。我怎样才能最大限度地减少它或使其变得更好？

Answer 1

如果你不想走反射路线，你应该可以使用 dynamic Linq供您查询。