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[ASP.net教程]MVC学习系列8


      分页和排序,应该是软件开发中,需要必知必会的技能了,对于分页,网上很多教程,当然,别人终究是别人的,只有自己理解,会了,并且吸收之后,再用自己的语言,传授出来,这才是硬道理。好了,废话说多了。现在我们进入正题:

     这里,我打算使用EF Code-First方式分页控件就是用PagedList.MVC,来做分页,对于排序,实现的思路是,加载数据出来之后,默认是升序排序,然后我们点击一下相应的列标题,就按照该字段降序排序,查数据。思路明确了,就开始干吧!

     1.首先新建一个空白的MVC项目,在Model文件夹里,新建一个Student实体

 

Student实体中的代码:

using System;using System.Collections.Generic;using System.Linq;using System.Web;namespace PagingAndSortingInMVC.Models{  public class Student  {    public int ID { get; set; }    public string Name { get; set; }    public string Sex { get; set; }    public string Email { get; set; }    public int Age { get; set; }   }}

2.添加EF引用之后,我们在根目录下,在创建一个文件夹Map,在里面创建一个类StudentMap

 

StudentMap类的代码:

using PagingAndSortingInMVC.Models;using System;using System.Collections.Generic;using System.ComponentModel.DataAnnotations.Schema;using System.Data.Entity.ModelConfiguration;using System.Linq;using System.Web;namespace PagingAndSortingInMVC.Map{  public class StudentMap:EntityTypeConfiguration<Student>  {    public StudentMap()    {      //配置主键      this.HasKey(s => s.ID);      //把ID列设置为自增列      this.Property(s => s.ID).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);      //配置列      this.Property(s => s.Name).HasMaxLength(50).IsRequired();      this.Property(s => s.Sex).HasMaxLength(2).IsRequired();      this.Property(s => s.Age).IsRequired();      this.Property(s => s.Email).HasMaxLength(100).IsRequired();    }  }}

3.在根目录下,再新建一个文件夹DBHelper,在里面新建一个类StudentDBContext

StudentDBContext类的代码:

using PagingAndSortingInMVC.Map;using System;using System.Collections.Generic;using System.Data.Entity;using System.Linq;using System.Web;namespace PagingAndSortingInMVC.DBHelper{  public class StudentDBContext:DbContext  {    public StudentDBContext()      : base("name=DbConnectionString")     {        }    protected override void OnModelCreating(DbModelBuilder modelBuilder)    {      //因为这里只有一个实体,就不搞的那么复杂了,不用反射来做。直接添加单个实体的配置      modelBuilder.Configurations.Add(new StudentMap());      base.OnModelCreating(modelBuilder);    }  }}

然后在配置文件中加上:

<connectionStrings><add name="DbConnectionString" connectionString="Server=.;Database=MyStudentDB;UID=sa;PWD=Password_1" providerName="System.Data.SqlClient"/></connectionStrings>

具体的位置在这:

4.好了,现在实体和数据库的配置都写好了,现在我们使用数据库迁移技术【Migrations】来自动生成数据库,

首先打开程序包管理控制台。

添加一行语句:Enable-Migrations,然后按回车键:

 这个时候,就在我们程序中生成了一个文件夹Migrations,里面有一个类Configuration:

修改Configuration类中的代码:把 AutomaticMigrationsEnabled 设置为true;并添加一句代码,让迁移过程中,没有数据丢失: 

AutomaticMigrationDataLossAllowed = false;

 

然后在程序包管理控制台中接着输入:

Update-Database -Verbose

  注意:【-Verbose和Database之间有空格】,之所以输入-Verbose就是可以在控制台看到生成的SQL语句:

PM> Update-Database -VerboseUsing StartUp project 'PagingAndSortingInMVC'.Using NuGet project 'PagingAndSortingInMVC'.Specify the '-Verbose' flag to view the SQL statements being applied to the target database.Target database is: 'MyStudentDB' (DataSource: ., Provider: System.Data.SqlClient, Origin: Configuration).No pending explicit migrations.Applying automatic migration: 201607180249098_AutomaticMigration.CREATE TABLE [dbo].[Students] (  [ID] [int] NOT NULL IDENTITY,  [Name] [nvarchar](50) NOT NULL,  [Sex] [nvarchar](2) NOT NULL,  [Email] [nvarchar](100) NOT NULL,  [Age] [int] NOT NULL,  CONSTRAINT [PK_dbo.Students] PRIMARY KEY ([ID]))CREATE TABLE [dbo].[__MigrationHistory] (  [MigrationId] [nvarchar](150) NOT NULL,  [ContextKey] [nvarchar](300) NOT NULL,  [Model] [varbinary](max) NOT NULL,  [ProductVersion] [nvarchar](32) NOT NULL,  CONSTRAINT [PK_dbo.__MigrationHistory] PRIMARY KEY ([MigrationId], [ContextKey]))INSERT [dbo].[__MigrationHistory]([MigrationId], [ContextKey], [Model], [ProductVersion])VALUES (N'201607180249098_AutomaticMigration', N'PagingAndSortingInMVC.Migrations.Configuration', 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unning Seed method.PM> 

 

 打开数据库,我们看到,就生成我们想要的数据库和表了:

 

5.既然要分页,就开始引入分页控件吧,引入PagedList.MVC

 

5.新建一个空白模板的Student控制器。

控制器里面就是我们主要的逻辑代码了:

 

using PagingAndSortingInMVC.DBHelper;using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.Mvc;using PagedList;using PagingAndSortingInMVC.Models;namespace PagingAndSortingInMVC.Controllers{  public class StudentController : Controller  {    private StudentDBContext db=null;    public StudentController()    {      db = new StudentDBContext();    }        /// <summary>    /// 首页【查询分页数据】    /// </summary>    /// <param name="sortBy">根据什么排序</param>    /// <param name="currentSort">当前排序字段</param>    /// <param name="page">当前页</param>    /// <returns></returns>    public ActionResult Index(string sortBy,string currentSort,int? page)    {      int pageIndex = 1;      int pageSize = 5;      //判断page是否有值,有的话就给值,没有就赋值1      pageIndex = page.HasValue ? Convert.ToInt32(page) : 1;      ViewBag.CurrentSort = sortBy;

//这句必须要,否则刚开始是空的,报错,就不能循环了。
sortBy = string.IsNullOrEmpty(sortBy) ? "Name" : sortBy; //如果sortBy为空,就设置为Name,下面设置的时候,默认按照名称排序

      IPagedList<Student> lstStudent = null;      switch (sortBy)      {        case "Name":          //如果sortBy==currentSort,就按照对应字段降序排列,并分页。否则升序。          if (sortBy.Equals(currentSort))          {            lstStudent = db.Set<Student>().              OrderByDescending(s => s.Name).              ToPagedList(pageIndex, pageSize);          }          else          {            lstStudent = db.Set<Student>().              OrderBy(s => s.Name).              ToPagedList(pageIndex, pageSize);          }          break;        case "Sex":          //如果sortBy==currentSort,就按照对应字段降序排列,并分页。否则升序。          if (sortBy.Equals(currentSort))          {            lstStudent = db.Set<Student>().              OrderByDescending(s => s.Sex).              ToPagedList(pageIndex, pageSize);          }          else          {            lstStudent = db.Set<Student>().              OrderBy(s => s.Sex).              ToPagedList(pageIndex, pageSize);          }          break;        case "Email":          //如果sortBy==currentSort,就按照对应字段降序排列,并分页。否则升序。          if (sortBy.Equals(currentSort))          {            lstStudent = db.Set<Student>().              OrderByDescending(s => s.Email).              ToPagedList(pageIndex, pageSize);          }          else          {            lstStudent = db.Set<Student>().              OrderBy(s => s.Email).              ToPagedList(pageIndex, pageSize);          }          break;        case "Age":          //如果sortBy==currentSort,就按照对应字段降序排列,并分页。否则升序。          if (sortBy.Equals(currentSort))          {            lstStudent = db.Set<Student>().              OrderByDescending(s => s.Age).              ToPagedList(pageIndex, pageSize);          }          else          {            lstStudent = db.Set<Student>().              OrderBy(s => s.Age).              ToPagedList(pageIndex, pageSize);          }          break;        default:          //如果sortBy==currentSort,就按照对应字段降序排列,并分页。否则升序。          if (sortBy.Equals(currentSort))          {            lstStudent = db.Set<Student>().              OrderByDescending(s => s.Name).              ToPagedList(pageIndex, pageSize);          }          else          {            lstStudent = db.Set<Student>().              OrderBy(s => s.Name).              ToPagedList(pageIndex, pageSize);          }          break;      }      return View(lstStudent);    }    public ActionResult AddStudent()    {      return View();    }    [HttpPost]    [ValidateAntiForgeryToken]    public ActionResult AddStudent(Student model)    {      db.Set<Student>().Add(model);      db.SaveChanges();      return RedirectToAction("Index");    }  }}

创建相对应的Index视图和AddStudent视图:

Index视图:

@using PagedList.Mvc;@*//引入分页的组件*@@model PagedList.IPagedList<PagingAndSortingInMVC.Models.Student>@{  ViewBag.Title = "Index";}<style>  table {    width: 100%;  }    table tr td {      border: 2px solid black;      text-align: center;      word-wrap: break-word;    }    table tr:hover {      background-color: #000;      color: #fff;    }    table tr th {      border: 2px solid black;      text-align: center;      background-color: #fff;      color: #000;    }</style> <h2>Index</h2><p>  @Html.ActionLink("Create New", "Create")</p>@using(Html.BeginForm("Index","Employee",FormMethod.Get)){ <table class="table">  <tr>    <th>      @* 通过创建匿名对象,传递参数到控制器中,new { sortBy = "Name", currentSort = ViewBag.CurrentSort }*@      @*参数的大小写无所谓,只要和控制器名称一样就行,sortBy,currentSort*@      @Html.ActionLink("Name", "Index", new { sortBy = "Name", currentSort = ViewBag.CurrentSort })    </th>    <th>      @Html.ActionLink("Sex", "Index", new { sortBy = "Sex", currentSort = ViewBag.CurrentSort })    </th>    <th>      @Html.ActionLink("Email", "Index", new { sortBy = "Email", currentSort = ViewBag.CurrentSort })    </th>    <th>      @Html.ActionLink("Age", "Index", new {sortBy = "Age", currentSort = ViewBag.CurrentSort })    </th>    <th></th>  </tr>@foreach (var item in Model) {  <tr>    <td>      @Html.DisplayFor(modelItem => item.Name)    </td>    <td>      @Html.DisplayFor(modelItem => item.Sex)    </td>    <td>      @Html.DisplayFor(modelItem => item.Email)    </td>    <td>      @Html.DisplayFor(modelItem => item.Age)    </td>    <td>          </td>  </tr>}</table>}<div id="Paging" style="text-align:center">  @*总页数是否小于当前页,小于就说明没数据,赋值0,否则赋值PageNumber*@   Page @(Model.PageCount< Model.PageNumber?0:Model.PageNumber) of @Model.PageCount   @Html.PagedListPager(Model, page => Url.Action("Index", new { page}),PagedListRenderOptions.Classic)</div>

 

 

 AddStudent视图:

@model PagingAndSortingInMVC.Models.Student@{  ViewBag.Title = "AddStudent";}<h2>AddStudent</h2>@using (Html.BeginForm()) {  @Html.AntiForgeryToken()    <div class="form-horizontal">    <h4>Student</h4>    <hr />    @Html.ValidationSummary(true, "", new { @class = "text-danger" })    <div class="form-group">      @Html.LabelFor(model => model.Name, htmlAttributes: new { @class = "control-label col-md-2" })      <div class="col-md-10">        @Html.EditorFor(model => model.Name, new { htmlAttributes = new { @class = "form-control" } })        @Html.ValidationMessageFor(model => model.Name, "", new { @class = "text-danger" })      </div>    </div>    <div class="form-group">      @Html.LabelFor(model => model.Sex, htmlAttributes: new { @class = "control-label col-md-2" })      <div class="col-md-10">        @Html.EditorFor(model => model.Sex, new { htmlAttributes = new { @class = "form-control" } })        @Html.ValidationMessageFor(model => model.Sex, "", new { @class = "text-danger" })      </div>    </div>    <div class="form-group">      @Html.LabelFor(model => model.Email, htmlAttributes: new { @class = "control-label col-md-2" })      <div class="col-md-10">        @Html.EditorFor(model => model.Email, new { htmlAttributes = new { @class = "form-control" } })        @Html.ValidationMessageFor(model => model.Email, "", new { @class = "text-danger" })      </div>    </div>    <div class="form-group">      @Html.LabelFor(model => model.Age, htmlAttributes: new { @class = "control-label col-md-2" })      <div class="col-md-10">        @Html.EditorFor(model => model.Age, new { htmlAttributes = new { @class = "form-control" } })        @Html.ValidationMessageFor(model => model.Age, "", new { @class = "text-danger" })      </div>    </div>    <div class="form-group">      <div class="col-md-offset-2 col-md-10">        <input type="submit" value="Create" class="btn btn-default" />      </div>    </div>  </div>}<div>  @Html.ActionLink("Back to List", "Index")</div><script src="~/Scripts/jquery-1.10.2.min.js"></script><script src="~/Scripts/jquery.validate.min.js"></script><script src="~/Scripts/jquery.validate.unobtrusive.min.js"></script>

 

接着修改一下布局页:

<!DOCTYPE html><html><head>  <meta charset="utf-8" />  <meta name="viewport" content="width=device-width, initial-scale=1.0">  <title>@ViewBag.Title - My ASP.NET Application</title>  <link href="~/Content/Site.css" rel="stylesheet" type="text/css" />  <link href="~/Content/bootstrap.min.css" rel="stylesheet" type="text/css" />  <script src="~/Scripts/modernizr-2.6.2.js"></script></head><body>  <div class="navbar navbar-inverse navbar-fixed-top">    <div class="container">      <div class="navbar-header">        <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">          <span class="icon-bar"></span>          <span class="icon-bar"></span>          <span class="icon-bar"></span>        </button>        @Html.ActionLink("Application name", "Index", "Home", new { area = "" }, new { @class = "navbar-brand" })      </div>      <div class="navbar-collapse collapse">        <ul class="nav navbar-nav">          @Html.ActionLink("Student List","Index")          @Html.ActionLink("Add Student ", "AddStudent")        </ul>      </div>    </div>  </div>  <div class="container body-content">    @RenderBody()    <hr />    <footer>      <p>&copy; @DateTime.Now.Year - My ASP.NET Application</p>    </footer>  </div>  <script src="~/Scripts/jquery-1.10.2.min.js"></script>  <script src="~/Scripts/bootstrap.min.js"></script></body></html>

 

修改一下默认路由:

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.Mvc;using System.Web.Routing;namespace PagingAndSortingInMVC{  public class RouteConfig  {    public static void RegisterRoutes(RouteCollection routes)    {      routes.IgnoreRoute("{resource}.axd/{*pathInfo}");      routes.MapRoute(        name: "Default",        url: "{controller}/{action}/{id}",        defaults: new { controller = "Student", action = "Index", id = UrlParameter.Optional }      );    }  }}

 

运行项目:

刚开始没有任何数据,我们添加几条测试数据:

 

 我们来验证一下,结果:

 

 看到了么,点击相应的列标题就可以进行排序了。分页也实现了。当然分页的样式可以通过改变这个选项:

 @Html.PagedListPager(Model, page => Url.Action("Index", new { page}),PagedListRenderOptions.Classic)

 

 这里,我修改了一下

 @Html.PagedListPager(Model, page => Url.Action("Index", new { page}),PagedListRenderOptions.TwitterBootstrapPager)

 分页控件的效果就是这样了。

 

 

 好了,这篇文章到此结束。

总结:分页和排序是很重要的功能,需要熟练掌握。