Asp.net mvc 3 ASP.NET MVC 3页面列表。方法'；跳过'；仅支持LINQ to实体中的排序输入。

为什么它在返回视图（contacts.ToPagedList（pageNumber，pageSize））中出现错误语句索引方法中的错误：

方法“Skip”仅支持LINQ to实体中的排序输入。方法“OrderBy”必须在方法“Skip”之前调用。

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using PhoneBook.Models;
using PagedList;

namespace PhoneBook.Controllers
{ 
public class ContactsController : Controller
{
    private PhoneDBContext db = new PhoneDBContext();

    //
    // GET: /Contacts/

    public ViewResult Index(string searchString, string sortOrder, Contact model, string currentFilter, int? page)
    {
        ViewBag.CurrentSort = sortOrder;

        ViewBag.FNameSortParm = sortOrder == "FName asc"? "FName desc" : "FName asc";
        ViewBag.DateSortParm = sortOrder == "Date asc" ? "Date desc" : "Date asc";
        ViewBag.LNameSortParm = sortOrder == "LName asc" ? "LName desc" : "LName asc";
        ViewBag.CompSortParm = sortOrder == "Company asc" ? "Company desc" : "Company asc";
        ViewBag.MobSortParm = sortOrder == "Mob asc" ? "Mob desc" : "Mob asc";
        ViewBag.TelSortParm = sortOrder == "Tel asc" ? "Tel desc" : "Tel asc";

        if (Request.HttpMethod == "GET") { searchString = currentFilter; }
        else {page = 1;}
        ViewBag.CurrentFilter = searchString;
        var contacts = from m in db.Contacts
                       select m;

        switch (sortOrder)
        {
            case "FName desc":
                contacts = contacts.OrderByDescending(s => s.FirstName);
                break;
            case "FName asc":
                contacts = contacts.OrderBy(s => s.FirstName);
                break;
            case "LName desc":
                contacts = contacts.OrderByDescending(s => s.LastName);
                break;
            case "LName asc":
                contacts = contacts.OrderBy(s => s.LastName);
                break;
            case "Company desc":
                contacts = contacts.OrderByDescending(s => s.Company);
                break;
            case "Company asc":
                contacts = contacts.OrderBy(s => s.Company);
                break;
            case "Date desc":
                contacts = contacts.OrderByDescending(s => s.DateAdded);
                break;
            case "Date asc":
                contacts = contacts.OrderBy(s => s.DateAdded);
                break;
            case "Mob desc":
                contacts = contacts.OrderByDescending(s => s.MobileNumber);
                break;
            case "Mob asc":
                contacts = contacts.OrderBy(s => s.MobileNumber);
                break;
            case "Tel desc":
                contacts = contacts.OrderByDescending(s => s.TelephoneNumber);
                break;
            case "Tel asc":
                contacts = contacts.OrderBy(s => s.TelephoneNumber);
                break;
        }


        if (!String.IsNullOrEmpty(searchString))
        {
            contacts = contacts.Where(s => s.LastName.ToUpper().Contains(searchString)||s.FirstName.ToUpper().Contains(searchString)||s.Company.ToUpper().Contains(searchString));
        }

        int pageSize = 3;
        int pageNumber = (page ?? 1);

       return View(contacts.ToPagedList(pageNumber, pageSize));
    }

    //
    // GET: /Contacts/Details/5

    public ViewResult Details(int id)
    {
        Contact contact = db.Contacts.Find(id);
        return View(contact);
    }

    //
    // GET: /Contacts/Create

    public ActionResult Create()
    {
        return View();
    } 

    //
    // POST: /Contacts/Create

    [HttpPost]
    public ActionResult Create(Contact contact)
    {
        if (ModelState.IsValid)
        {
            db.Contacts.Add(contact);
            contact.DateAdded = DateTime.Now;
            db.SaveChanges();
            return RedirectToAction("Index");  
        }

        return View(contact);
    }

    //
    // GET: /Contacts/Edit/5

    public ActionResult Edit(int id=0)
    {

        Contact contact = db.Contacts.Find(id);

        if (contact == null)    { return HttpNotFound(); } // returns blank page if id is not valid
        return View(contact);
    }

    //
    // POST: /Contacts/Edit/5

    [HttpPost]
    public ActionResult Edit(Contact contact)
    {
        if (ModelState.IsValid)
        {


            db.Entry(contact).State = EntityState.Modified;
            contact.DateAdded = DateTime.Now;
            db.SaveChanges();
            return RedirectToAction("Index");
        }
        return View(contact);
    }

    //
    // GET: /Contacts/Delete/5

    public ActionResult Delete(int id)
    {
        Contact contact = db.Contacts.Find(id);
        if (contact == null) { return HttpNotFound(); }
        return View(contact);
    }

    //
    // POST: /Contacts/Delete/5

    [HttpPost, ActionName("Delete")]
    public ActionResult DeleteConfirmed(int id)
    {            
        Contact contact = db.Contacts.Find(id);
        if (contact == null) { return HttpNotFound(); }
        db.Contacts.Remove(contact);
        db.SaveChanges();
        return RedirectToAction("Index");
    }

    public ActionResult SearchIndex(string searchString)
    {
        var contacts = from m in db.Contacts
                     select m;

        if (!String.IsNullOrEmpty(searchString))
        {
            contacts = contacts.Where(s => s.LastName.Contains(searchString));
        }

        return View(contacts);
    }

    protected override void Dispose(bool disposing)
    {
        db.Dispose();
        base.Dispose(disposing);
    }


}
}

下面是Index.cshtml代码：

@model PagedList.IPagedList<PhoneBook.Models.Contact>
@{
    ViewBag.Title = "Phone Book";
}

<p>

     @using (Html.BeginForm()){   
         <p> Search: @Html.TextBox("SearchString", ViewBag.CurrentFilter as string) 
         <input type="submit" value="Go" /></p>
        }
</p>


<p>
    @Html.ActionLink("Create New", "Create")
</p>

<table>
    <tr>
        <th>
             @Html.ActionLink("First Name", "Index", new { sortOrder=ViewBag.FNameSortParm, currentFilter=ViewBag.CurrentFilter })
        </th>
        <th>
             @Html.ActionLink("Last Name", "Index", new { sortOrder = ViewBag.LNameSortParm, currentFilter = ViewBag.CurrentFilter })
        </th>
        <th>
            @Html.ActionLink("Mobile Num", "Index", new { sortOrder = ViewBag.MobSortParm, currentFilter = ViewBag.CurrentFilter })
        </th>
        <th>
            @Html.ActionLink("Tel Num", "Index", new { sortOrder = ViewBag.TelSortParm, currentFilter = ViewBag.CurrentFilter })
        </th>
        <th>
             @Html.ActionLink("Company", "Index", new { sortOrder = ViewBag.CompSortParm, currentFilter = ViewBag.CurrentFilter })
        </th>
        <th>
           @Html.ActionLink("Date Added/Updated", "Index", new { sortOrder = ViewBag.DateSortParm, currentFilter = ViewBag.CurrentFilter })
        </th>
        <th></th>
    </tr>

@foreach (var item in Model) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.FirstName)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.LastName)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.MobileNumber)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.TelephoneNumber)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Company)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.DateAdded)
        </td>
        <td>
            @Html.ActionLink("Details", "Details", new { id=item.ID })
            @Html.ActionLink("Edit", "Edit", new { id=item.ID }) 
            @Html.ActionLink("Delete", "Delete", new { id=item.ID })
        </td>
    </tr>
}

</table>

<div>
    Page @(Model.PageCount < Model.PageNumber ? 0 : Model.PageNumber)
    of @Model.PageCount

    @if (Model.HasPreviousPage)
    {
        @Html.ActionLink("<<", "Index", new { page = 1, sortOrder = ViewBag.CurrentSort, currentFilter=ViewBag.CurrentFilter  })
        @Html.Raw(" ");
        @Html.ActionLink("< Prev", "Index", new { page = Model.PageNumber - 1, sortOrder = ViewBag.CurrentSort, currentFilter=ViewBag.CurrentFilter  })
    }
    else
    {
        @:<<
        @Html.Raw(" ");
        @:< Prev
    }

    @if (Model.HasNextPage)
    {
        @Html.ActionLink("Next >", "Index", new { page = Model.PageNumber + 1, sortOrder = ViewBag.CurrentSort, currentFilter=ViewBag.CurrentFilter  })
        @Html.Raw(" ");
        @Html.ActionLink(">>", "Index", new { page = Model.PageCount, sortOrder = ViewBag.CurrentSort, currentFilter=ViewBag.CurrentFilter  })
    }
    else
    {
        @:Next >
        @Html.Raw(" ")
        @:>>
    }
</div>

@model PagedList.IPagedList
@{
ViewBag.Title=“电话簿”；
}

@使用（Html.BeginForm（））{
搜索：@Html.TextBox（“搜索字符串”，ViewBag.CurrentFilter为字符串）

}


@ActionLink（“新建”、“创建”）

@ActionLink（“名字”，“索引”，新{sortOrder=ViewBag.FNameSortParm，currentFilter=ViewBag.currentFilter}）
@ActionLink（“姓氏”，“索引”，新{sortOrder=ViewBag.LNameSortParm，currentFilter=ViewBag.currentFilter}）
@ActionLink（“Mobile Num”，“Index”，new{sortOrder=ViewBag.MobSortParm，currentFilter=ViewBag.currentFilter}）
@ActionLink（“电话号码”，“索引”，新的{sortOrder=ViewBag.TelSortParm，currentFilter=ViewBag.currentFilter}）
@ActionLink（“公司”，“索引”，新{sortOrder=ViewBag.CompSortParm，currentFilter=ViewBag.currentFilter}）
@ActionLink（“添加/更新的日期”，“索引”，新的{sortOrder=ViewBag.DateSortParm，currentFilter=ViewBag.currentFilter}）
@foreach（模型中的var项目）{
@DisplayFor（modelItem=>item.FirstName）
@DisplayFor（modelItem=>item.LastName）
@DisplayFor（modelItem=>item.MobileNumber）
@DisplayFor（modelItem=>item.TelephoneNumber）
@DisplayFor（modelItem=>item.Company）
@DisplayFor（modelItem=>item.DateAdd）
@ActionLink（“详细信息”，“详细信息”，新的{id=item.id}）
@ActionLink（“编辑”，“编辑”，新的{id=item.id}）
@ActionLink（“删除”，“删除”，新的{id=item.id}）
}
页码@（Model.PageCount”，“Index”，新{page=Model.PageCount，sortOrder=ViewBag.CurrentSort，currentFilter=ViewBag.currentFilter}）
}
其他的
{
@：下一步>
@Html.Raw（“”）
@:>>
}

尝试以下三种更改

将此代码置于switch语句之前：

if (!String.IsNullOrEmpty(searchString))
{
    contacts = contacts.Where(s => s.LastName.ToUpper().Contains(searchString)||s.FirstName.ToUpper().Contains(searchString)||s.Company.ToUpper().Contains(searchString));
}

在switch语句中添加一个

default

大小写，并使其抛出

switch (sortOrder) {
    case ...:
        ...
    default:
        throw new ArgumentException("Bad sort order specified", "sortOrder");
}

使用类型

IOrderedQueryable

IOrderedQueryable orderedContacts；
开关（分拣机）
{
案例“FName desc”：
orderedContacts=contacts.OrderByDescending（s=>s.FirstName）；
打破
...
}
...
返回视图（orderedContacts.ToPagedList（pageNumber，pageSize））；

---

谢谢第二个代码片段帮助了我，我认为错误是由

开关（sortOrder）

块中的

sortOrder

变量引起的。ReturnView对如何处理排序器感到困惑，因为它不是为页面列表显示而订购的。。如果我错了，请纠正我。。。然后我安装了最新版本的页面列表。。。谢谢你帮我解决这个问题。这不是一个完整的答案。请说明这是怎么回事。在分页之前是否将整个数据库表加载到内存中？坏主意。

IOrderedQueryable<T> orderedContacts;
switch (sortOrder)
{
    case "FName desc":
        orderedContacts = contacts.OrderByDescending(s => s.FirstName);
        break;
    ...
}

...

return View(orderedContacts.ToPagedList(pageNumber, pageSize));

return View(orderedContacts.ToList().ToPagedList(pageNumber, pageSize));