Mvc Asp排序项目

本文关键字:项目 排序 Asp Mvc | 更新日期: 2023-09-27 18:22:08

我在应用程序中使用了PagedList.MVC进行分页。这很好用。寻呼工作正常,OrderBy下拉列表也工作正常。当我从下拉列表中选择值时,它会给出所需的排序结果。我的意思是,如果我选择A-Z,它会按升序对项目进行精细排序,但当我点击第二页或下一页时,它不会对任何项目进行排序,url会变成这样

http://localhost:41213/Home/Products?page=2&pageSize=6

此外,我如何使pageSize=6成为动态页面?我想把它放在像{5,10,15,20}这样的下拉列表中,当用户选择一个值时,它应该显示所选的项目数量。

控制器

    [HttpGet]
    public ActionResult Products(int? OrderBy, int page=1, int pageSize=6)
    {
        private Shopping db = new Shopping();
        switch (OrderBy)
        {
            case 1:
                List<Product> listProductsasc = db.Products.OrderBy(p => p.Name).ToList();
                PagedList<Product> modelasc = new PagedList<Product>(listProductsasc, page, pageSize);
                return View(modelasc);
            case 2:
                List<Product> listProductsdesc = db.Products.OrderByDescending(p => p.Name).ToList();
                PagedList<Product> modeldesc = new PagedList<Product>(listProductsdesc, page, pageSize);
                return View(modeldesc);
            default:
                List<Product> listProducts = db.Products.ToList();
                PagedList<Product> modeldefault = new PagedList<Product>(listProducts, page, pageSize);
                return View(modeldefault);
        }
    }

查看

@model PagedList.IPagedList<FypStore.Models.Product>
@using PagedList.Mvc
<div class="row">
        <div class="col-sm-6">
            @using (Html.BeginForm("Products", "Home", FormMethod.Get, new { id = "Form1" }))
            {
                <div class="col-sm-8">
                    Sort by:
                    @Html.DropDownList("OrderBy", new List<SelectListItem>
                     {
                        new SelectListItem{ Text="A-Z", Value = "1" },
                        new SelectListItem{ Text="Z-A", Value = "2" }
                     }, "-- Order By --")
                </div>
                <div class="col-sm-4">
                    <div class="form-group">
                        <div class="col-md-offset-2 col-md-10">
                            <input type="submit" class="btn btn-default" value="Filter" />
                        </div>
                    </div>
                </div>
            }
        </div>
</div>
<br />
@Html.PagedListPager(Model, page => Url.Action("Products", new { page, pageSize = Model.PageSize }))
Showing @Model.FirstItemOnPage to @Model.LastItemOnPage of @Model.TotalItemCount Products

Mvc Asp排序项目

您需要修改PagedListPager()方法的路由参数,以包括排序顺序的值,例如

@Html.PagedListPager(Model, page => Url.Action("Products", new { OrderBy = ViewBag.SortOrder, page, pageSize = Model.PageSize }))

然后在方法中,包括

ViewBag.SortOrder = OrderBy;

在返回视图之前。然而,更好的方法是使用包含视图使用的属性的视图模型,该视图模型将解决代码中的其他问题(例如,如果您选择"Z-A"选项并提交表单,当您返回表单时,集合已排序,但下拉列表显示"-- Order By --",表示其未排序。您的视图模型应该是

public class ProductsVM
{
  [Display(Name = "Sort by:")]
  public int? OrderBy { get; set; }
  public IEnumerable<SelectListItem> OrderList { get; set; }
  public int Page { get; set; }
  public int PageSize { get; set; }
  PagedList<Product> Products { get; set; }
}

控制器方法是

[HttpGet]
public ActionResult Products(int? orderBy, int page=1, int pageSize=6)
{
  private Shopping db = new Shopping();
  IEnumerable<Product> products = db.Products; // not .ToList()
  if (orderBy == 1)
  {
    products = products.OrderBy(p => p.Name);
  }
  else if (orderBy == 2)
  {
    products = products.OrderByDescending(p => p.Name)
  }
  ProductsVM model = new ProductsVM
  {
    OrderBy = orderBy,
    OrderList = new List<SelectListItem>
    {
      new SelectListItem{ Text="A-Z", Value = "1" },
      new SelectListItem{ Text="Z-A", Value = "2" }
    },
    Page = page,
    PageSize = pageSize,
    Products = new PagedList<Product>(products, page, pageSize);
  };
  return View(model);
}

最后修改您的视图以使用视图模型

@model ProductsVM
....
@using (Html.BeginForm("Products", "Home", FormMethod.Get))
{
  @Html.LabelFor(m => m.OrderBy)
  @Html.DropDownListForFor(m => m.OrderBy, Model.OrderList, "-- Order By --")
  <input type="submit" class="btn btn-default" value="Filter" />
}
@Html.PagedListPager(Model.Products, page => Url.Action("Products", new { orderBy = Model.OrderBy, page, pageSize = Model.PageSize }))
Showing @Model.Products.FirstItemOnPage to @Model.Products.LastItemOnPage of @Model.Products.TotalItemCount Products

要修复页面链接,需要将OrderBy参数传递给视图。最简单的方法是使用ViewBag。在您的控制器中:

[HttpGet]
public ActionResult Products(int? OrderBy, int page = 1, int pageSize = 2)
{
    ViewBag.OrderBy = OrderBy;
    ...

在您看来:

@Html.PagedListPager(Model, page => Url.Action("Products", new { page, pageSize = Model.PageSize, OrderBy = ViewBag.OrderBy }))

另一种方法是使用视图模型。创建一个名为ProductsViewModel的类,并在控制器中填充其属性,如下所示:

List<Product> modelasc = new PagedList<Product>(listProductsasc, page, pageSize);
var viewModel = ProductsViewModel();
viewModel.Products = modelasc;
viewModel.OrderBy = OrderBy;
return View(viewModel);

并在视图中使用它们:

@model FypStore.Models.ProductsViewModel
...
@Html.PagedListPager(Model, page => Url.Action("Products", new { page, pageSize = Model.Products.PageSize, OrderBy = Model.OrderBy }))

此外,我如何使pageSize=6成为动态页面?

您可以使用与OrderBy参数相同的方法:使用名称pageSize:制作下拉列表

<div class="col-sm-8">
    Page size:
    @Html.DropDownList("pageSize", new List<SelectListItem>
            {
            new SelectListItem{ Text="2", Value = "2" },
            new SelectListItem{ Text="3", Value = "3" }
            }, "-- Page Size --")
</div>

旁注:您可能希望在控制器中删除查询的.ToList();部分,然后将其移到其他位置。因为现在您的代码从数据库中获取所有数据,然后对其进行排序并提取必要数量的产品。您应该始终在数据库端执行排序和分页逻辑,并且只获取要在当前页面上显示的产品。