ASP.NET?MVC+EF實(shí)現(xiàn)異步增刪改查

更新時(shí)間：2022年03月23日 08:52:54 作者：.NET開(kāi)發(fā)菜鳥(niǎo)

這篇文章介紹了ASP.NET?MVC+EF實(shí)現(xiàn)異步增刪改查的方法，文中通過(guò)示例代碼介紹的非常詳細(xì)。對(duì)大家的學(xué)習(xí)或工作具有一定的參考借鑒價(jià)值，需要的朋友可以參考下

功能實(shí)現(xiàn)

我們以學(xué)生為例，實(shí)現(xiàn)增刪改查功能。

1、搭建UI層

我們這里使用ASP.NET MVC作為界面層顯示數(shù)據(jù)，首先創(chuàng)建一個(gè)解決方案，然后添加一個(gè)MVC項(xiàng)目，命名為TaskAsync.UI，創(chuàng)建后的項(xiàng)目結(jié)構(gòu)如下圖所示：

2、添加實(shí)體類

我們把實(shí)體類放在單獨(dú)的類庫(kù)里面，新建一個(gè)類型項(xiàng)目，命名為TaskAsync.Model，里面有一個(gè)Student類，Student類代碼如下：

namespace TaskAsync.Model
{
    /// <summary>
    /// 學(xué)生類
    /// </summary>
    public class Student
    {
        /// <summary>
        /// 主鍵
        /// </summary>
        public int Id { get; set; }

        /// <summary>
        /// 姓名
        /// </summary>
        public string Name { get; set; }

        /// <summary>
        /// 年齡
        /// </summary>
        public int Age { get; set; }

        /// <summary>
        /// 性別
        /// </summary>
        public int Gender { get; set; }
    }
}

3、添加服務(wù)接口層

我們把增刪改查的方法定義在接口里面，新添加一個(gè)類型項(xiàng)目，命名為TaskAsync.IService，需要引用上面創(chuàng)建的實(shí)體類庫(kù)。里面有一個(gè)IStudentService接口，接口代碼如下：

using System.Collections.Generic;
using System.Threading.Tasks;
using TaskAsync.Model;

namespace TaskAsync.IService
{
    public interface IStudentService
    {
        /// <summary>
        /// 增加的異步方法
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        Task<int> AddPersonAsync(Student entity);

        /// <summary>
        /// 刪除的異步方法
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        Task<int> DeleteByIdAsync(int id);

        /// <summary>
        /// 獲取所有數(shù)據(jù)
        /// </summary>
        /// <returns></returns>
        Task<IEnumerable<Student>> GetAllAsync();

        /// <summary>
        /// 根據(jù)Id獲取單一值
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        Task<Student> GetStudentByIdAsync(int id);

        /// <summary>
        /// 更新的異步方法
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        Task<int> UpdateAsync(Student entity);
    }
}

所有的方法返回值都是Task<T>類型的，方法名稱默認(rèn)以Async結(jié)尾，標(biāo)注為異步方法。

4、添加Entity Framework

我們使用EF作為ORM框架，把EF放在單獨(dú)類庫(kù)里面，命名為TaskAsync.Data。直接在NuGet里面安裝：

安裝完成以后，我們同樣需要在創(chuàng)建的ASP.NET MVC程序里面EntityFramework，然后在外層的Web.config文件里面添加鏈接字符串：

<connectionStrings>
    <add name="EFContext" connectionString="Data Source=.;Initial Catalog=TaskAsyncDb;User ID=sa;Password=123456;" providerName="System.Data.SqlClient" />
  </connectionStrings>

注意：鏈接字符串里面的providerName不能省略，否則進(jìn)行數(shù)據(jù)遷移的時(shí)候會(huì)報(bào)錯(cuò)。

我們?cè)赥askAsync.Data項(xiàng)目里面添加數(shù)據(jù)上下文類，繼承自父類的DbContext：

using System.Data.Entity;
using TaskAsync.Model;

namespace TaskAsync.Data
{
    /// <summary>
    /// 數(shù)據(jù)上下文類，繼承自父類的DbContext
    /// </summary>
    public class AppDbContext:DbContext
    {
        /// <summary>
        /// 通過(guò)創(chuàng)建連接，給父類的構(gòu)造函數(shù)傳遞參數(shù)
        /// 參數(shù)是連接字符串的名稱
        /// 表示使用連接字符串中名字為DbConnectionString的去連接數(shù)據(jù)庫(kù)
        /// </summary>
        public AppDbContext():base("name=DbConnectionString")
        {

        }

        /// <summary>
        /// 重寫OnModelCreating方法
        /// </summary>
        /// <param name="modelBuilder"></param>
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            // 配置生成的表名
            modelBuilder.Entity<Student>().ToTable("T_Student");
            base.OnModelCreating(modelBuilder);
        }

        public DbSet<Student> Students { get; set; }
    }
}

數(shù)據(jù)上下文類創(chuàng)建完成以后，我們接下來(lái)在程序包管理器控制臺(tái)里面進(jìn)行數(shù)據(jù)遷移：

注意：項(xiàng)目要選擇EntityFramework所在的類庫(kù)項(xiàng)目。

1、開(kāi)啟遷移

使用下面的命令開(kāi)啟數(shù)據(jù)遷移：

Enable-Migrations

命令執(zhí)行如下圖所示：

2、增加遷移

使用下面的命令開(kāi)始遷移：

Add-Migration Init

命令執(zhí)行如下圖所示：

執(zhí)行成功以后，會(huì)在TaskAsync.Data項(xiàng)目下面添加一個(gè)Migrations文件夾

這個(gè)文件夾下面有兩個(gè)類文件：Configuration.cs文件里面是配置信息，另外一個(gè)是本次遷移記錄文件。我們?cè)贑onfiguration.cs類里面添加一些種子數(shù)據(jù)：

namespace TaskAsync.Data.Migrations
{
    using System.Collections.Generic;
    using System.Data.Entity.Migrations;
    using System.Linq;
    using TaskAsync.Model;

    internal sealed class Configuration : DbMigrationsConfiguration<TaskAsync.Data.AppDbContext>
    {
        public Configuration()
        {
            AutomaticMigrationsEnabled = false;
        }

        protected override void Seed(TaskAsync.Data.AppDbContext context)
        {
            List<Student> list = new List<Student>()
            {
                new Student()
                {
                    Name="Jack",
                    Age=23,
                    Gender=1
                },
                new Student()
                {
                    Name="Tom",
                    Age=25,
                    Gender=2
                }
            };

            if(!context.Students.Any())
            {
                context.Students.AddRange(list);
            }
        }
    }
}

3、生成數(shù)據(jù)庫(kù)

我們?cè)谏厦媾渲猛瓿梢院?，就可以使用下面的命令去生成?shù)據(jù)庫(kù)：

Update-Database

命令執(zhí)行如下圖所示：

命令執(zhí)行成功，就會(huì)自動(dòng)創(chuàng)建數(shù)據(jù)庫(kù)和表，表里面插入我們添加的種子數(shù)據(jù)：

5、添加接口的實(shí)現(xiàn)類

我們添加IStudentService接口的實(shí)現(xiàn)類。添加一個(gè)單獨(dú)的類庫(kù)，命名為TaskAsync.Service，并添加對(duì)TaskAsync.Model、TaskAsync.IService、TaskAsync.Data的引用，然后實(shí)現(xiàn)IStudentService接口：

using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using TaskAsync.Data;
using TaskAsync.IService;
using TaskAsync.Model;

namespace TaskAsync.Service
{
    public class StudentService : IStudentService
    {
        /// <summary>
        /// 新增 方法標(biāo)注為async
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        public async Task<int> AddPersonAsync(Student entity)
        {
            using (AppDbContext dbContext = new AppDbContext())
            {
                dbContext.Students.Add(entity);
                // 調(diào)用異步方法
                int count = await dbContext.SaveChangesAsync();
                return count;
            }
        }

        /// <summary>
        /// 刪除
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        public async Task<int> DeleteByIdAsync(int id)
        {
            using (AppDbContext dbContext = new AppDbContext())
            {
                Student student =await dbContext.Students.FindAsync(new object[] { id });
                if(student!=null)
                {
                    dbContext.Students.Remove(student);
                    return await dbContext.SaveChangesAsync();
                }
                else
                {
                    return 0;
                }
            }
        }

        public async Task<IEnumerable<Student>> GetAllAsync()
        {
            List<Student> list = await Task.Run<List<Student>>(() => 
            {
                using (AppDbContext dbContext = new AppDbContext())
                {
                    return dbContext.Students.ToList();
                }
            });

            return list;
        }

        public async Task<Student> GetStudentByIdAsync(int id)
        {
            using (AppDbContext dbContext = new AppDbContext())
            {
                Student student = await dbContext.Students.FindAsync(new object[] { id });
                if (student != null)
                {
                    return student
                }
                else
                {
                    return null;
                }
            }
        }

        public async Task<int> UpdateAsync(Student entity)
        {
            using (AppDbContext dbContext = new AppDbContext())
            {
                Student student = await dbContext.Students.FindAsync(new object[] { entity.Id });
                if (student != null)
                {
                    student.Name = entity.Name;
                    student.Age = entity.Age;
                    student.Gender = entity.Gender;
                    dbContext.Entry(student).State = System.Data.Entity.EntityState.Modified;
                    return await dbContext.SaveChangesAsync();
                }
                else
                {
                    return 0;
                }
            }
        }
    }
}

注意：這里同樣需要添加到EntityFramework的引用。

6、添加控制器

我們?cè)贏SP.NET MVC項(xiàng)目里面首先添加對(duì)上面幾個(gè)類庫(kù)的引用。

為了測(cè)試方法，我們直接添加一個(gè)包含視圖的MVC5控制器（使用Entity Framework），這樣就會(huì)自動(dòng)生成UI界面了，如下圖所示：

模型類選擇Student，數(shù)據(jù)上下文類選擇AppDbContext，如下圖所示：

創(chuàng)建完成之后，會(huì)看到自動(dòng)添加了視圖：

控制器里也自動(dòng)生成了代碼：

using System.Data.Entity;
using System.Linq;
using System.Net;
using System.Web.Mvc;
using TaskAsync.Data;
using TaskAsync.Model;

namespace TaskAsync.UI.Controllers
{
    public class StudentController : Controller
    {
        private AppDbContext db = new AppDbContext();

        // GET: Student
        public ActionResult Index()
        {
            return View(db.Students.ToList());
        }

        // GET: Student/Details/5
        public ActionResult Details(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Student student = db.Students.Find(id);
            if (student == null)
            {
                return HttpNotFound();
            }
            return View(student);
        }

        // GET: Student/Create
        public ActionResult Create()
        {
            return View();
        }

        // POST: Student/Create
        // 為了防止“過(guò)多發(fā)布”攻擊，請(qǐng)啟用要綁定到的特定屬性，有關(guān) 
        // 詳細(xì)信息，請(qǐng)參閱 https://go.microsoft.com/fwlink/?LinkId=317598。
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create([Bind(Include = "Id,Name,Age,Gender")] Student student)
        {
            if (ModelState.IsValid)
            {
                db.Students.Add(student);
                db.SaveChanges();
                return RedirectToAction("Index");
            }

            return View(student);
        }

        // GET: Student/Edit/5
        public ActionResult Edit(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Student student = db.Students.Find(id);
            if (student == null)
            {
                return HttpNotFound();
            }
            return View(student);
        }

        // POST: Student/Edit/5
        // 為了防止“過(guò)多發(fā)布”攻擊，請(qǐng)啟用要綁定到的特定屬性，有關(guān) 
        // 詳細(xì)信息，請(qǐng)參閱 https://go.microsoft.com/fwlink/?LinkId=317598。
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Edit([Bind(Include = "Id,Name,Age,Gender")] Student student)
        {
            if (ModelState.IsValid)
            {
                db.Entry(student).State = EntityState.Modified;
                db.SaveChanges();
                return RedirectToAction("Index");
            }
            return View(student);
        }

        // GET: Student/Delete/5
        public ActionResult Delete(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Student student = db.Students.Find(id);
            if (student == null)
            {
                return HttpNotFound();
            }
            return View(student);
        }

        // POST: Student/Delete/5
        [HttpPost, ActionName("Delete")]
        [ValidateAntiForgeryToken]
        public ActionResult DeleteConfirmed(int id)
        {
            Student student = db.Students.Find(id);
            db.Students.Remove(student);
            db.SaveChanges();
            return RedirectToAction("Index");
        }

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

但是框架生成的代碼都是同步方法的，不是我們需要的，我們改成異步的方法：

using System.Data.Entity;
using System.Linq;
using System.Net;
using System.Threading.Tasks;
using System.Web.Mvc;
using TaskAsync.Data;
using TaskAsync.IService;
using TaskAsync.Model;
using TaskAsync.Service;

namespace TaskAsync.UI.Controllers
{
    public class StudentController : Controller
    {
        //private AppDbContext db = new AppDbContext();

        IStudentService service = new StudentService();
        // GET: Student
        public async Task<ActionResult> Index()
        {
            return View(await service.GetAllAsync());
        }

        // GET: Student/Details/5
        public async Task<ActionResult> Details(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Student student =await service.GetStudentByIdAsync((int)id);
            if (student == null)
            {
                return HttpNotFound();
            }
            return View(student);
        }

        // GET: Student/Create
        public ActionResult Create()
        {
            return View();
        }

        // POST: Student/Create
        // 為了防止“過(guò)多發(fā)布”攻擊，請(qǐng)啟用要綁定到的特定屬性，有關(guān) 
        // 詳細(xì)信息，請(qǐng)參閱 https://go.microsoft.com/fwlink/?LinkId=317598。
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async  Task<ActionResult> Create([Bind(Include = "Id,Name,Age,Gender")] Student student)
        {
            if (ModelState.IsValid)
            {
                int count = await service.AddPersonAsync(student);
                if(count>0)
                {
                    return RedirectToAction("Index");
                }
            }

            return View(student);
        }

        // GET: Student/Edit/5
        public async Task<ActionResult> Edit(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Student student = await service.GetStudentByIdAsync((int)id);
            if (student == null)
            {
                return HttpNotFound();
            }
            return View(student);
        }

        // POST: Student/Edit/5
        // 為了防止“過(guò)多發(fā)布”攻擊，請(qǐng)啟用要綁定到的特定屬性，有關(guān) 
        // 詳細(xì)信息，請(qǐng)參閱 https://go.microsoft.com/fwlink/?LinkId=317598。
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<ActionResult> Edit([Bind(Include = "Id,Name,Age,Gender")] Student student)
        {
            if (ModelState.IsValid)
            {
                int count = await service.UpdateAsync(student);
                if (count > 0)
                {
                    return RedirectToAction("Index");
                }
            }
            return View(student);
        }

        // GET: Student/Delete/5
        public async  Task<ActionResult> Delete(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Student student = await service.GetStudentByIdAsync((int)id);
            if (student == null)
            {
                return HttpNotFound();
            }
            return View(student);
        }

        // POST: Student/Delete/5
        [HttpPost, ActionName("Delete")]
        [ValidateAntiForgeryToken]
        public async Task<ActionResult> DeleteConfirmed(int id)
        {
            int count = await service.DeleteByIdAsync(id);
            return RedirectToAction("Index");
        }

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

然后我們?cè)谛薷腳Layout.cshtml視圖文件，添加學(xué)生管理的一個(gè)標(biāo)簽：

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>@ViewBag.Title - 我的 ASP.NET 應(yīng)用程序</title>
    @Styles.Render("~/Content/css")
    @Scripts.Render("~/bundles/modernizr")
</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("應(yīng)用程序名稱", "Index", "Home", new { area = "" }, new { @class = "navbar-brand" })
            </div>
            <div class="navbar-collapse collapse">
                <ul class="nav navbar-nav">
                    <li>@Html.ActionLink("主頁(yè)", "Index", "Home")</li>
                    <li>@Html.ActionLink("關(guān)于", "About", "Home")</li>
                    <li>@Html.ActionLink("聯(lián)系方式", "Contact", "Home")</li>
                    <li>@Html.ActionLink("學(xué)生管理", "Index", "Student")</li>
                </ul>
            </div>
        </div>
    </div>
    <div class="container body-content">
        @RenderBody()
        <hr />
        <footer>
            <p>? @DateTime.Now.Year - 我的 ASP.NET 應(yīng)用程序</p>
        </footer>
    </div>

    @Scripts.Render("~/bundles/jquery")
    @Scripts.Render("~/bundles/bootstrap")
    @RenderSection("scripts", required: false)
</body>
</html>

運(yùn)行程序，點(diǎn)擊“學(xué)生管理”標(biāo)簽，就可以看到列表數(shù)據(jù)了：