本次参考学习了


https://www.cnblogs.com/ymnets/p/3424309.htmlC


这个人的教程

但是由于时代久远，教程节奏快，版本的问题。对于初学者来说，很不友好。

正好我也要学习，所以自己重新写一下，顺带改一改其中的小bug。

系统目标：实现一个权限管理案例 用户—角色—权限

本节目标

：将数据库中的数据的展示在前台

1.直接呱唧呱唧上代码吧

上一节，我们一起添加了EF模型

下面的截图中红色圈出来的部分是需要创建的。

注意哪些是类，哪些是接口


创建完控制器后，记得顺带把视图创建了

当然，这部分代码中，有一部分并没有起到作用，后面会用到

还有一部分代码，是下一节才会创建的，但是本节会用的，所以就先创建了

莫怪某怪

• 
  SysSampleBLL
  
• 
  ISysSampleBLL
  
• 
  SysSampleRepository
  
• 
  ISysSampleRepository
  
• 
  GridPager
  
• 
  ValidationErrorHelper
  
• 
  SysSampleController
  
• 
  SysSampleModel
  

<1>SysSampleBLL

using Apps.App.DAL;
using Apps.App.IBLL;
using Apps.App.IDAL;
using Apps.App.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace Apps.App.BLL
{
    public class SysSampleBLL
    {
        DBContainer db = new DBContainer();

        ISysSampleRepository Rep = new SysSampleRepository();


        /// <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<SysSample> GetList(string queryStr)
        {

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


            return queryData.ToList();
        }

        /// <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(SysSample entity)
        {
            try
            {
                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)
            {
                //ExceptionHander.WriteException(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(SysSample entity)
        {
            try
            {
                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 SysSample GetById(string id)
        {
            if (IsExist(id))
            {
                SysSample entity = Rep.GetById(id);


                return entity;
            }
            else
            {
                return null;
            }
        }

        /// <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);
        }
    }
}

<2>ISysSampleBLL

using Apps.App.Common;
using Apps.Models.Sys;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Apps.App.IBLL
{
    interface ISysSampleBLL
    {
        /// <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>
        List<SysSampleModel> GetList(ref GridPager pager, string queryStr);
        /// <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>
        bool Create(ref ValidationErrors errors, SysSampleModel model);
        /// <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>
        bool Delete(ref ValidationErrors errors, string id);
        /// <summary>
        /// 删除多个实体，中断将回滚
        /// </summary>
        /// <param name="errors">持久的错误信息</param>
        /// <param name="deleteCollection">主键数组集合</param>
        /// <returns>是否成功</returns>
        bool Delete(ref ValidationErrors errors, string[] deleteCollection);
        /// <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>
        bool Edit(ref ValidationErrors errors, SysSampleModel model);
        /// <summary>
        /// 根据ID获得一个Model实体
        /// </summary>
        /// <param name="id">id</param>
        /// <returns>Model实体</returns>
        SysSampleModel GetById(string id);
        /// <summary>
        /// 判断是否存在实体
        /// </summary>
        /// <param name="id">主键ID</param>
        /// <returns>是否存在</returns>
        bool IsExist(string id);
    }
}

<3>SysSampleRepository

using Apps.App.IDAL;
using Apps.App.Models;
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;

namespace Apps.App.DAL
{
    public class SysSampleRepository : ISysSampleRepository, IDisposable
    {
        /// <summary>
        /// 获取列表
        ///</summary>
        /// <param name="db">数据库上下文</param>
        /// <returns>数据列表</returns>
        public IQueryable<SysSample> GetList(DBContainer db)
        {
            IQueryable<SysSample>
                list = db.SysSample.AsQueryable();
            return list;
        }
        /// <summary>
        /// 创建一个实体
        ///</summary>
        /// <param name="db">数据库上下文</param>
        /// <param name="entity">实体</param>
        public int Create(SysSample entity)
        {
            using (DBContainer db = new DBContainer())
            {
                db.Set<SysSample>().Add(entity);
                return db.SaveChanges();
            }
        }
        /// <summary>
        /// 删除一个实体
        ///</summary>
        /// <param name="db">数据库上下文</param>
        /// <param name="entity">主键ID</param>
        public int Delete(string id)
        {
            using (DBContainer db = new DBContainer())
            {
                SysSample entity = db.SysSample.SingleOrDefault(a => a.Id == id);
                db.Set<SysSample>().Remove(entity);
                return db.SaveChanges();
            }
        }

        /// <summary>
        /// 修改一个实体
        ///</summary>
        /// <param name="db">数据库上下文</param>
        /// <param name="entity">实体</param>
        public int Edit(SysSample entity)
        {
            using (DBContainer db = new DBContainer())
            {
                db.Set<SysSample>().Attach(entity);
                db.Entry<SysSample>(entity).State = EntityState.Modified;
                return db.SaveChanges();
            }
        }
        /// <summary>
        /// 获得一个实体
        ///</summary>
        /// <param name="id">id</param>
        /// <returns>实体</returns>
        public SysSample GetById(string id)
        {
            using (DBContainer db = new DBContainer())
            {
                return db.SysSample.SingleOrDefault(a => a.Id == id);
            }
        }
        /// <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)
        {
            using (DBContainer db = new DBContainer())
            {
                SysSample entity = GetById(id);
                if (entity != null)
                    return true;
                return false;
            }
        }
        public void Dispose()
        {

        }
    }
}

<4>ISysSampleRepository

using Apps.App.Models;
using System.Linq;


namespace Apps.App.IDAL
{
    interface ISysSampleRepository
    {
        /// <summary>
        /// 获取列表
        /// </summary>
        /// <param name="db">数据库上下文</param>
        /// <returns>数据列表</returns>
        IQueryable<SysSample> GetList(DBContainer db);
        /// <summary>
        /// 创建一个实体
        /// </summary>
        /// <param name="entity">实体</param>
        int Create(SysSample entity);
        /// <summary>
        /// 删除一个实体
        /// </summary>
        /// <param name="entity">主键ID</param>
        int Delete(string id);

        /// <summary>
        /// 修改一个实体
        /// </summary>
        /// <param name="entity">实体</param>
        int Edit(SysSample entity);
        /// <summary>
        /// 获得一个实体
        /// </summary>
        /// <param name="id">id</param>
        /// <returns>实体</returns>
        SysSample GetById(string id);
        /// <summary>
        /// 判断一个实体是否存在
        /// </summary>
        bool IsExist(string id);
    }
}

<5>GridPager

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace Apps.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 sort { 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);
            }
        }
    }
}

<6>ValidationErrorHelper

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace Apps.App.Common
{
    public class ValidationErrorHelper
    {
    }
    public class ValidationError
    {
        public ValidationError() { }
        public string ErrorMessage { get; set; }

    }
    public class ValidationErrors : List<ValidationError>
    {
        /// <summary>
        /// 添加错误
        /// </summary>
        /// <param name="errorMessage">信息描述</param>
        public void Add(string errorMessage)
        {
            base.Add(new ValidationError { ErrorMessage = errorMessage });
        }
        /// <summary>
        /// 获取错误集合
        /// </summary>
        public string Error
        {
            get
            {
                string error = "";
                this.All(a => {
                    error += a.ErrorMessage;
                    return true;
                });
                return error;
            }
        }
    }
}

<7>SysSampleController

using Apps.App.BLL;
using Apps.App.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace Apps.Controllers
{
    public class SysSampleController : Controller
    {
        // GET: SysSample
        public ActionResult Index()
        {
            SysSampleBLL bll = new SysSampleBLL();
            List<SysSample> list = bll.GetList("");
            return View(list);
        }
    }
}

<8>SysSampleModel

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;

namespace Apps.Models.Sys
{
    public class SysSampleModel
    {
        [Display(Name = "ID")]
        public string Id { get; set; }


        [Display(Name = "名称")]
        public string Name { get; set; }


        [Display(Name = "年龄")]
        [Range(0, 10000)]
        public int? Age { get; set; }

        [Display(Name = "生日")]
        public DateTime? Bir { get; set; }

        [Display(Name = "照片")]
        public string Photo { get; set; }


        [Display(Name = "简介")]
        public string Note { get; set; }

        [Display(Name = "创建时间")]
        public DateTime? CreateTime { get; set; }
    }
}

好了到现在我们把后台代码基本完成了，下面添加前台代码

@using Apps;
@model IEnumerable<Apps.App.Models.SysSample>

@{
    Layout = null;
}

<!DOCTYPE html>

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Index</title>
</head>
<body>
    <p>
        @Html.ActionLink("Create New", "Create")
    </p>
    <table>
        <tr>
            <th>
                @Html.DisplayNameFor(model => model.Name)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Age)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Bir)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Photo)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Note)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.CreateTime)
            </th>
            <th></th>
        </tr>

        @foreach (var item in Model)
        {
            <tr>
                <td>
                    @Html.DisplayFor(modelItem => item.Name)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.Age)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.Bir)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.Photo)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.Note)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.CreateTime)
                </td>
                <td>
                    @Html.ActionLink("Edit", "Edit", new { id = item.Id }) |
                    @Html.ActionLink("Details", "Details", new { id = item.Id }) |
                    @Html.ActionLink("Delete", "Delete", new { id = item.Id })
                </td>
            </tr>
        }

    </table>
</body>
</html>

让我们一起运行一下代码看看





有的伙伴就郁闷了，为啥自己没有数据显示。。。

自己去数据库填写几条几可以了

下面我们再去修改一下第一篇文章那个界面，把这次界面啊嵌入到那个里面

来，运行这个页面





OK！！！！！

2.总结

说实话

只读原文章

有几处坑

emmmm

好了我们这一节的小任务就算完成了，不足的地方欢迎批评指正