MVC与EasyUI DataGrid 分页

上一节我们讲了,DataGrid获取数据的一些用法,这一节讲DataGrid的分页

  • DataGrid将传递“当前页码”“每页条数”

  • 控制器获取参数之后交给BLL层处理逻辑和分页,返回总页数和当前页的数据

  • 最后交给DataGrid处理

课外:从此次前端的处理速度我看出,没有以前的JQGrid控件的处理数据快。

首先在让DataGrid支持分页,我们需要加入几个属性

  1. 是否启用分页:pagination 默认是false

  2. 每页数量:pageSize 默认10

  3. 可选择每页数量:pageList 默认[10,20,30,40,50]

  4. 排序字段:sortName 默认null

  5. 排序类型:sortOrder 默认asc

OK加入后的代码变成这样


  $(function () {
        $('#List').datagrid({
            url: '/SysSample/GetList',
            width: $(window).width() - 10,
            methord: 'post',
            height: $(window).height() - 35,
            fitColumns: true,
            sortName: 'Id',
            sortOrder: 'desc',
            idField: 'Id',
            pageSize: 15,
            pageList: [15, 20, 30, 40, 50],
            pagination: true,
            striped: true, //奇偶行是否区分
            singleSelect: true,//单选模式
            rownumbers: true,//行号
            columns: [[
                { field: 'Id', title: 'ID', width: 80 },
                { field: 'Name', title: '名称', width: 120 },
                { field: 'Age', title: '年龄', width: 80, align: 'right' },
                { field: 'Bir', title: '生日', width: 80, align: 'right' },
                { field: 'Photo', title: '照片', width: 250 },
                { field: 'Note', title: '说明', width: 60, align: 'center' },
                { field: 'CreateTime', title: '创建时间', width: 60, align: 'center' }
            ]]
        });
    });

预览一下

实际已经分页,但是不正确的,每一页的数据一样。我们要根据分页的参数去取

我们打开谷歌浏览器,看他传递了什么

OK我们控制器要根据他传递的参数写同样的参数名称,否则获取不到

看我们的SysSampleController 下的GetList方法,加入参数


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using App.BLL;
using App.IBLL;
using App.Models;
using App.Models.Sys;
using Microsoft.Practices.Unity;

namespace App.Admin.Controllers
{
    public class SysSampleController : Controller
    {
        //
        // GET: /SysSample/
        /// <summary>
        /// 业务层注入
        /// </summary>
        [Dependency]
        public ISysSampleBLL m_BLL { get; set; }
        public ActionResult Index()
        {
            
            return View();
        }
        [HttpPost]
        public JsonResult GetList(int page = 1, int rows = 10, string sort = "Id", string order = "desc")
        {
            int total = 0;
            List<SysSampleModel> list = m_BLL.GetList(page, rows, sort, order, ref total);
            var json = new
            {
                total = total,
                rows = (from r in list
                        select new SysSampleModel()
                        {

                            Id = r.Id,
                            Name = r.Name,
                            Age = r.Age,
                            Bir = r.Bir,
                            Photo = r.Photo,
                            Note = r.Note,
                            CreateTime = r.CreateTime,

                        }).ToArray()
            };
            return Json(json, JsonRequestBehavior.AllowGet);
        }
    }
}

BLL代码修改(IBLL也要修改参数 List<SysSampleModel> GetList(int page, int rows, string sort, string order,ref int total);)


using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Practices.Unity;
using App.Models;
using App.Common;
using App.Models.Sys;
using App.IBLL;
using App.IDAL;


namespace App.BLL
{
    public class SysSampleBLL : ISysSampleBLL
    {
        DBContainer db = new DBContainer();
        [Dependency]
        public ISysSampleRepository Rep { get; set; }
        /// <summary>
        /// 获取列表
        /// </summary>
        /// <param name="pager">JQgrid分页</param>
        /// <param name="queryStr">搜索条件</param>
        /// <returns>列表</returns>
        public List<SysSampleModel> GetList(int page, int rows, string sort, string order, ref int total)
        {
            IQueryable<SysSample> queryData = null;
            queryData = Rep.GetList(db);
            
            //排序
            if (order == "desc")
            {
                switch (order)
                {
                    case "Id":
                        queryData = queryData.OrderByDescending(c => c.Id);
                        break;
                    case "Name":
                        queryData = queryData.OrderByDescending(c => c.Name);
                        break;
                    default:
                        queryData = queryData.OrderByDescending(c => c.CreateTime);
                        break;
                }
            }
            else
            {

                switch (order)
                {
                    case "Id":
                        queryData = queryData.OrderBy(c => c.Id);
                        break;
                    case "Name":
                        queryData = queryData.OrderBy(c => c.Name);
                        break;
                    default:
                        queryData = queryData.OrderBy(c => c.CreateTime);
                        break;
                }
            }
            return CreateModelList(ref queryData,page,rows,ref total);
        }


        private List<SysSampleModel> CreateModelList(ref IQueryable<SysSample> queryData,int page,int rows,ref int total)
        {

            total = queryData.Count();
            if (total > 0)
            {
                if (page <= 1)
                {
                    queryData = queryData.Take(rows);
                }
                else
                {
                    queryData = queryData.Skip((page - 1) * rows).Take(rows);
                }
            }
            List<SysSampleModel> modelList = (from r in queryData
                                              select new SysSampleModel
                                              {
                                                  Id = r.Id,
                                                  Name = r.Name,
                                                  Age = r.Age,
                                                  Bir = r.Bir,
                                                  Photo = r.Photo,
                                                  Note = r.Note,
                                                  CreateTime = r.CreateTime,

                                              }).ToList();

            return modelList;
        }

        /// <summary>
        /// 创建一个实体
        /// </summary>
        /// <param name="errors">持久的错误信息</param>
        /// <param name="model">模型</param>
        /// <returns>是否成功</returns>
        public bool Create( SysSampleModel model)
        {
            try
            {
                SysSample entity = Rep.GetById(model.Id);
                if (entity != null)
                {
                    return false;
                }
                entity = new SysSample();
                entity.Id = model.Id;
                entity.Name = model.Name;
                entity.Age = model.Age;
                entity.Bir = model.Bir;
                entity.Photo = model.Photo;
                entity.Note = model.Note;
                entity.CreateTime = model.CreateTime;

                if (Rep.Create(entity) == 1)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch (Exception ex)
            {
                //ExceptionHander.WriteException(ex);
                return false;
            }
        }
        /// <summary>
        /// 删除一个实体
        /// </summary>
        /// <param name="errors">持久的错误信息</param>
        /// <param name="id">id</param>
        /// <returns>是否成功</returns>
        public bool Delete(string id)
        {
            try
            {
                if (Rep.Delete(id) == 1)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch (Exception ex)
            {
                return false;
            }
        }
   
        /// <summary>
        /// 修改一个实体
        /// </summary>
        /// <param name="errors">持久的错误信息</param>
        /// <param name="model">模型</param>
        /// <returns>是否成功</returns>
        public bool Edit(SysSampleModel model)
        {
            try
            {
                SysSample entity = Rep.GetById(model.Id);
                if (entity == null)
                {
                    return false;
                }
                entity.Name = model.Name;
                entity.Age = model.Age;
                entity.Bir = model.Bir;
                entity.Photo = model.Photo;
                entity.Note = model.Note;


                if (Rep.Edit(entity) == 1)
                {
                    return true;
                }
                else
                {

                    return false;
                }

            }
            catch (Exception ex)
            {

                //ExceptionHander.WriteException(ex);
                return false;
            }
        }
        /// <summary>
        /// 判断是否存在实体
        /// </summary>
        /// <param name="id">主键ID</param>
        /// <returns>是否存在</returns>
        public bool IsExists(string id)
        {
            if (db.SysSample.SingleOrDefault(a => a.Id == id) != null)
            {
                return true;
            }
            return false;
        }
        /// <summary>
        /// 根据ID获得一个实体
        /// </summary>
        /// <param name="id">id</param>
        /// <returns>实体</returns>
        public SysSampleModel GetById(string id)
        {
            if (IsExist(id))
            {
                SysSample entity = Rep.GetById(id);
                SysSampleModel model = new SysSampleModel();
                model.Id = entity.Id;
                model.Name = entity.Name;
                model.Age = entity.Age;
                model.Bir = entity.Bir;
                model.Photo = entity.Photo;
                model.Note = entity.Note;
                model.CreateTime = entity.CreateTime;

                return model;
            }
            else
            {
                return new SysSampleModel();
            }
        }

        /// <summary>
        /// 判断一个实体是否存在
        /// </summary>
        /// <param name="id">id</param>
        /// <returns>是否存在 true or false</returns>
        public bool IsExist(string id)
        {
            return Rep.IsExist(id);
        }
    }
}

我们要在BLL层返回当前查询的全部条数,还要返回当前页得数据

这里我们用到“ref”关键字:传递引用,简单理解下,我们把一个参数count传递给BLL,BLL再把它传递给DAL,假设count=0加入ref在BLL处理是10,那么返回就是 10如果没有加ref那么count还是0,这等于一个持久的可赋值的变量,现在可以分页和返回查询条件的条数了 到DataGrid浏览一下,OK没问题。

大家看出这样太麻烦了,代码太不漂亮了,我们把常用的参数给封装了。这个是我封装类库


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace App.Common
{
     public class GridPager
    {
 
      
         public int rows { get; set; }//每页行数
         public int page { get; set; }//当前页是第几页
         public string order { get; set; }//排序方式
         public string sord { get; set; }//排序列
         public int totalRows { get; set; }//总行数

         public int totalPages //总页数
         {
             get
             {
                 return (int)Math.Ceiling((float)totalRows / (float)rows);
             }
         }
    }
}

把这个类放到App.Common, 我们的App.Common终于用到了 再次修改Controller的GetList


   [HttpPost]
        public JsonResult GetList(GridPager pager)
        {
            List<SysSampleModel> list = m_BLL.GetList(ref pager);
            var json = new
            {
                total = pager.totalRows,
                rows = (from r in list
                        select new SysSampleModel()
                        {

                            Id = r.Id,
                            Name = r.Name,
                            Age = r.Age,
                            Bir = r.Bir,
                            Photo = r.Photo,
                            Note = r.Note,
                            CreateTime = r.CreateTime,

                        }).ToArray()

            };

            return Json(json, JsonRequestBehavior.AllowGet);
        }

和修改BLL的GetList 还要修改IBLL --List<SysSampleModel> GetList(ref GridPager pager);


using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Practices.Unity;
using App.Models;
using App.Common;
using App.Models.Sys;
using App.IBLL;
using App.IDAL;


namespace App.BLL
{
    public class SysSampleBLL : ISysSampleBLL
    {
        DBContainer db = new DBContainer();
        [Dependency]
        public ISysSampleRepository Rep { get; set; }
        /// <summary>
        /// 获取列表
        /// </summary>
        /// <param name="pager">JQgrid分页</param>
        /// <param name="queryStr">搜索条件</param>
        /// <returns>列表</returns>
        public List<SysSampleModel> GetList(ref GridPager pager)
        {

            IQueryable<SysSample> queryData = null;
          
                queryData = Rep.GetList(db);

            //排序
            if (pager.order == "desc")
            {
                switch (pager.order)
                {
                    case "CreateTime":
                        queryData = queryData.OrderByDescending(c => c.CreateTime);
                        break;
                    case "Name":
                        queryData = queryData.OrderByDescending(c => c.Name);
                        break;
                    default:
                        queryData = queryData.OrderByDescending(c => c.CreateTime);
                        break;
                }
            }
            else
            {

                switch (pager.order)
                {
                    case "CreateTime":
                        queryData = queryData.OrderBy(c => c.CreateTime);
                        break;
                    case "Name":
                        queryData = queryData.OrderBy(c => c.Name);
                        break;
                    default:
                        queryData = queryData.OrderBy(c => c.CreateTime);
                        break;
                }
            }
            return CreateModelList(ref pager, ref queryData);
        }
        private List<SysSampleModel> CreateModelList(ref GridPager pager, ref IQueryable<SysSample> queryData)
        {

            pager.totalRows = queryData.Count();
            if (pager.totalRows > 0)
            {
                if (pager.page <= 1)
                {
                    queryData = queryData.Take(pager.rows);
                }
                else
                {
                    queryData = queryData.Skip((pager.page - 1) * pager.rows).Take(pager.rows);
                }
            }
            List<SysSampleModel> modelList = (from r in queryData
                                              select new SysSampleModel
                                              {
                                                  Id = r.Id,
                                                  Name = r.Name,
                                                  Age = r.Age,
                                                  Bir = r.Bir,
                                                  Photo = r.Photo,
                                                  Note = r.Note,
                                                  CreateTime = r.CreateTime,

                                              }).ToList();

            return modelList;
        }

        /// <summary>
        /// 创建一个实体
        /// </summary>
        /// <param name="errors">持久的错误信息</param>
        /// <param name="model">模型</param>
        /// <returns>是否成功</returns>
        public bool Create( SysSampleModel model)
        {
            try
            {
                SysSample entity = Rep.GetById(model.Id);
                if (entity != null)
                {
                    return false;
                }
                entity = new SysSample();
                entity.Id = model.Id;
                entity.Name = model.Name;
                entity.Age = model.Age;
                entity.Bir = model.Bir;
                entity.Photo = model.Photo;
                entity.Note = model.Note;
                entity.CreateTime = model.CreateTime;

                if (Rep.Create(entity) == 1)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch (Exception ex)
            {
                //ExceptionHander.WriteException(ex);
                return false;
            }
        }
        /// <summary>
        /// 删除一个实体
        /// </summary>
        /// <param name="errors">持久的错误信息</param>
        /// <param name="id">id</param>
        /// <returns>是否成功</returns>
        public bool Delete(string id)
        {
            try
            {
                if (Rep.Delete(id) == 1)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch (Exception ex)
            {
                return false;
            }
        }
   
        /// <summary>
        /// 修改一个实体
        /// </summary>
        /// <param name="errors">持久的错误信息</param>
        /// <param name="model">模型</param>
        /// <returns>是否成功</returns>
        public bool Edit(SysSampleModel model)
        {
            try
            {
                SysSample entity = Rep.GetById(model.Id);
                if (entity == null)
                {
                    return false;
                }
                entity.Name = model.Name;
                entity.Age = model.Age;
                entity.Bir = model.Bir;
                entity.Photo = model.Photo;
                entity.Note = model.Note;


                if (Rep.Edit(entity) == 1)
                {
                    return true;
                }
                else
                {

                    return false;
                }

            }
            catch (Exception ex)
            {

                //ExceptionHander.WriteException(ex);
                return false;
            }
        }
        /// <summary>
        /// 判断是否存在实体
        /// </summary>
        /// <param name="id">主键ID</param>
        /// <returns>是否存在</returns>
        public bool IsExists(string id)
        {
            if (db.SysSample.SingleOrDefault(a => a.Id == id) != null)
            {
                return true;
            }
            return false;
        }
        /// <summary>
        /// 根据ID获得一个实体
        /// </summary>
        /// <param name="id">id</param>
        /// <returns>实体</returns>
        public SysSampleModel GetById(string id)
        {
            if (IsExist(id))
            {
                SysSample entity = Rep.GetById(id);
                SysSampleModel model = new SysSampleModel();
                model.Id = entity.Id;
                model.Name = entity.Name;
                model.Age = entity.Age;
                model.Bir = entity.Bir;
                model.Photo = entity.Photo;
                model.Note = entity.Note;
                model.CreateTime = entity.CreateTime;

                return model;
            }
            else
            {
                return new SysSampleModel();
            }
        }

        /// <summary>
        /// 判断一个实体是否存在
        /// </summary>
        /// <param name="id">id</param>
        /// <returns>是否存在 true or false</returns>
        public bool IsExist(string id)
        {
            return Rep.IsExist(id);
        }
    }
}

代码漂亮了不少,预览一下,还是正确的效果了。

好,这一讲我们就讲到这里,我不知道这种讲解大家是否看得很反感,因为这很循序渐进,是要这样好呢?还是直接上好代码就可以了?大家响应一下

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