[聚合文章] 在ASP.NET MVC中使用Web API和EntityFramework构建应用程序

.Net 2018-02-12 9 阅读

最近做了一个项目技术预研:在ASP.NET MVC框架中使用Web API和EntityFramework,构建一个基础的架构,并在此基础上实现基本的CRUD应用。

以下是详细的步骤。

第一步

在数据库中创建一张数据表,表名为Customer,见下图:

第二步

  • 打开 Visual Studio,新建项目。

  • 选择'ASP.NET Web Application',命名为'WebApi'。

  • 我们要创建一个'Web API',在模板中选择'Web API',点击'确定'。

    第三步

    接下来我要添加一个类。

  • 右键点击这个 web api项目,添加一个'ADO.NET Entity Data Model'。

  • 添加'EF Designer from database',点击'下一步'。

  • 在配置窗口中添加新连接,输入服务器名称,选择数据库,点击'确定'。

  • 点击'下一步',选择要关联的数据表。

  • 点击'完成'。

    第四步

    现在的工作就是要为Wep Api添加控制器了。

  • 右键选择'controllers'文件夹。

  • 选择'MVC5 Controller with views, using Entity Framework'。

  • 点击'添加'。

  • 选择数据模型类Customer,选择Data context类文件,本例中为SystemTestEntity。

  • 设置控制器名称为CustomersController,点击'添加'。

    上述操作完成后,CustomerController.cs会自动生成。

CustomerController.cs

using System.Data.Entity;  using System.Data.Entity.Infrastructure;  using System.Linq;  using System.Net;  using System.Web.Http;  using System.Web.Http.Description;  using CRUDWebApiExam.Models;    namespace CRUDWebApiExam.Controllers  {      public class CustomersController : ApiController      {          private SystemTestEntities db = new SystemTestEntities();            // GET: api/Customers          public IQueryable<Customer> GetCustomer()          {              return db.Customer;          }            // GET: api/Customers/5          [ResponseType(typeof(Customer))]          public IHttpActionResult GetCustomer(int id)          {              Customer customer = db.Customer.Find(id);              if (customer == null)              {                  return NotFound();              }              return Ok(customer);          }            // PUT: api/Customers/5          [ResponseType(typeof(void))]          public IHttpActionResult PutCustomer(int id, Customer customer)          {              if (!ModelState.IsValid)              {                  return BadRequest(ModelState);              }              if (id != customer.CustomerId)              {                  return BadRequest();              }              db.Entry(customer).State = EntityState.Modified;              try              {                  db.SaveChanges();              }              catch (DbUpdateConcurrencyException)              {                  if (!CustomerExists(id))                  {                      return NotFound();                  }                  else                  {                      throw;                  }              }              return StatusCode(HttpStatusCode.NoContent);          }            // POST: api/Customers          [ResponseType(typeof(Customer))]          public IHttpActionResult PostCustomer(Customer customer)          {              if (!ModelState.IsValid)              {                  return BadRequest(ModelState);              }              db.Customer.Add(customer);              db.SaveChanges();               return CreatedAtRoute("DefaultApi", new { id = customer.CustomerId }, customer);          }            // DELETE: api/Customers/5          [ResponseType(typeof(Customer))]          public IHttpActionResult DeleteCustomer(int id)          {              Customer customer = db.Customer.Find(id);              if (customer == null)              {                  return NotFound();              }              db.Customer.Remove(customer);              db.SaveChanges();              return Ok(customer);          }            protected override void Dispose(bool disposing)          {              if (disposing)              {                  db.Dispose();              }              base.Dispose(disposing);          }            private bool CustomerExists(int id)          {              return db.Customer.Count(e => e.CustomerId == id) > 0;          }      }  }  

运行这个 Web Api项目,你会看到下面的结果

第五步

到此为止,web api已经构建成功了。接下来我们需要为这个web api服务添加消费对象了,这个消费对象就是本文要涉及的MVC项目。

  • 首先要添加一个model类,我们可以直接采用上文中的Customer类。右键点击models文件夹,添加类并命名。本例中,我直接命名为Customer.cs。
    Customer.cs
using System;  using System.ComponentModel.DataAnnotations;    namespace MVCPersatantion.Models  {      public class Customer      {          [Display(Name = "CustomerId")]          public int CustomerId { get; set; }          [Display(Name = "Name")]          public string Name { get; set; }          [Display(Name = "Address")]          public string Address { get; set; }          [Display(Name = "MobileNo")]          public string MobileNo { get; set; }          [Display(Name = "Birthdate")]          [DataType(DataType.Date)]          public DateTime Birthdate { get; set; }          [Display(Name = "EmailId")]          public string EmailId { get; set; }              }   }  
  • customer类添加完成后,接下来需要添加一个ViewModel文件夹,并在里面新建一个CustomerViewModel.cs文件。
    CustomerViewModel.cs
using MVCPersatantion.Models;    namespace MVCPersatantion.ViewModel  {      public class CustomerViewModel      {          public Customer customer { get; set; }      }  }

第六步

我已经添加了一个消费web api服务的类,现在我还需要添加一个Client类。

  • 右键点击models文件夹,添加类文件CustomerClient.cs。
    CustomerClient.cs
using System;  using System.Collections.Generic;  using System.Net.Http;  using System.Net.Http.Headers;    namespace MVCPersatantion.Models  {      public class CustomerClient      {          private string Base_URL = "http://localhost:30110/api/";            public IEnumerable<Customer> findAll()          {              try              {                  HttpClient client = new HttpClient();                  client.BaseAddress = new Uri(Base_URL);                  client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));                  HttpResponseMessage response = client.GetAsync("customers").Result;                    if (response.IsSuccessStatusCode)                      return response.Content.ReadAsAsync<IEnumerable<Customer>>().Result;                  return null;              }              catch              {                  return null;              }          }          public Customer find(int id)          {              try              {                  HttpClient client = new HttpClient();                  client.BaseAddress = new Uri(Base_URL);                  client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));                  HttpResponseMessage response = client.GetAsync("customers/" + id).Result;                    if (response.IsSuccessStatusCode)                      return response.Content.ReadAsAsync<Customer>().Result;                  return null;              }              catch              {                  return null;              }          }          public bool Create(Customer customer)          {              try              {                  HttpClient client = new HttpClient();                  client.BaseAddress = new Uri(Base_URL);                  client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));                  HttpResponseMessage response = client.PostAsJsonAsync("customers", customer).Result;                  return response.IsSuccessStatusCode;              }              catch              {                  return false;              }          }          public bool Edit(Customer customer)          {              try              {                  HttpClient client = new HttpClient();                  client.BaseAddress = new Uri(Base_URL);                  client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));                  HttpResponseMessage response = client.PutAsJsonAsync("customers/" + customer.CustomerId, customer).Result;                  return response.IsSuccessStatusCode;              }              catch              {                  return false;              }          }          public bool Delete(int id)          {              try              {                  HttpClient client = new HttpClient();                  client.BaseAddress = new Uri(Base_URL);                  client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));                  HttpResponseMessage response = client.DeleteAsync("customers/" + id).Result;                  return response.IsSuccessStatusCode;              }              catch              {                  return false;              }          }      }  }

细心的朋友们可能已经发现,我的代码中有一些重复代码。实际应用中我们可以抽取成公用代码,这样任何地方都能够使用了。这里为了清楚的阐述过程,所以写了一些重复的代码。

我们看第一行private string Base_URL = "http://localhost:50985/api/",这个Base_URL是web api的服务地址。

接下来就可以编写Insert、Update、Delete、Select的业务逻辑了。

第七步

右键点击Controllers文件夹,添加一个名为Customer控制器,控制器中添加服务客户端调用的方法。

using System;  using System.Collections.Generic;  using System.Linq;  using System.Web;  using System.Web.Mvc;  using MVCPersatantion.Models;  using MVCPersatantion.ViewModel;    namespace MVCPersatantion.Controllers  {      public class CustomerController : Controller      {          // GET: Customer          public ActionResult Index()          {              CustomerClient CC = new CustomerClient();              ViewBag.listCustomers = CC.findAll();               return View();          }          [HttpGet]          public ActionResult Create()          {              return View("Create");          }          [HttpPost]          public ActionResult Create(CustomerViewModel cvm)          {              CustomerClient CC = new CustomerClient();              CC.Create(cvm.customer);              return RedirectToAction("Index");          }                   public ActionResult Delete(int id)          {              CustomerClient CC = new CustomerClient();              CC.Delete(id);              return RedirectToAction("Index");          }          [HttpGet]          public ActionResult Edit(int id)          {              CustomerClient CC = new CustomerClient();              CustomerViewModel CVM = new CustomerViewModel();              CVM.customer = CC.find(id);              return View("Edit",CVM);          }          [HttpPost]          public ActionResult Edit(CustomerViewModel CVM)          {              CustomerClient CC = new CustomerClient();              CC.Edit(CVM.customer);              return RedirectToAction("Index");          }      }  }  

第八步

  • 创建视图页面Index.cshtml。

  • 在Index页面中添加代码。
    Index.cshtml

@{    ViewBag.Title = "Index";}<h2>Index</h2><div align="center">    @Html.ActionLink("Create", "Create", "Customer", new { area = "" }, null)    <br /><br />    <table cellpadding="2"           class="table"           cellspacing="2"           border="1">        <tr class="btn-primary">            <th>                CustomerId            </th>            <th> Name</th>            <th> Address</th>            <th> MobileNo</th>            <th> Birthdate</th>            <th> EmailId</th>            <th> Action</th>        </tr>        @foreach (var Cust in ViewBag.listCustomers)        {            <tr class="btn-success">                <td>                    @Cust.CustomerId                </td>                <td>                    @Cust.Name                </td>                <td>                    @Cust.Address                </td>                <td>                    @Cust.MobileNo                </td>                <td>                    @Cust.Birthdate.ToString("dd/MM/yyyy")                </td>                <td>                    @Cust.EmailId                </td>                <td>                    <a onclick="return confirm('确定要删除这条数据?')"                       href="@Url.Action("Delete","Customer",new {id= Cust.CustomerId})">Delete</a> ||                    <a href="@Url.Action("Edit","Customer",new {id= Cust.CustomerId})">Edit</a>                   @*@Html.ActionLink("Edit", "Edit", "Customer", new { id = Cust.CustomerId })*@                </td>            </tr>        }    </table></div>
  • 添加新增数据模块Create。

  • 在Customer控制器中添加create方法,在view中增加Create.cshtml。

Create.cshtml

@model WebApiMVC.ViewModel.CustomerViewModel@{    ViewBag.Title = "Create";}<h2>Create</h2><div align = "center" >@using (Html.BeginForm("create", "Customer", FormMethod.Post)){    <table class="table">        <tr>            <td>                @Html.LabelFor(model => model.customer.Name)            </td>            <td>                @Html.TextBoxFor(model => model.customer.Name)            </td>        </tr>        <tr>            <td>                @Html.LabelFor(model => model.customer.Address)            </td>            <td>                @Html.TextBoxFor(model => model.customer.Address)            </td>        </tr>        <tr>            <td>                @Html.LabelFor(model => model.customer.MobileNo)            </td>            <td>                @Html.TextBoxFor(model => model.customer.MobileNo)            </td>        </tr>        <tr>            <td>                @Html.LabelFor(model => model.customer.Birthdate)            </td>            <td>                @Html.TextBoxFor(model => model.customer.Birthdate)            </td>        </tr>        <tr>            <td>                @Html.LabelFor(model => model.customer.EmailId)            </td>            <td>                @Html.TextBoxFor(model => model.customer.EmailId)            </td>        </tr>        <tr>            <td></td>            <td>                <input type="submit"  value="保存" />            </td>        </tr>    </table>}    </div>
  • 添加修改数据模块Edit。

  • 在Customer控制器中添加edit方法,在view中增加Edit.cshtml。

Edit.cshtml

@{    ViewBag.Title = "Edit";}@model WebApiMVC.ViewModel.CustomerViewModel<h2> Edit </h2><div align="center" width="500px">    @using (Html.BeginForm("Edit", "Customer", FormMethod.Post))    {        <table class="table"               width="400px"               cellpadding="20">            <tr class="btn-default">                <td>                    @Html.LabelFor(model => model.customer.Name)                </td>                <td>                    @Html.TextBoxFor(model => model.customer.Name)                </td>            </tr>            <tr>                <td>                    @Html.LabelFor(model => model.customer.Address)                </td>                <td>                    @Html.TextBoxFor(model => model.customer.Address)                </td>            </tr>            <tr>                <td>                    @Html.LabelFor(model => model.customer.MobileNo)                </td>                <td>                    @Html.TextBoxFor(model => model.customer.MobileNo)                </td>            </tr>            <tr>                <td>                    @Html.LabelFor(model => model.customer.Birthdate)                </td>                <td>                    @Html.TextBoxFor(model => model.customer.Birthdate)                </td>            </tr>            <tr>                <td>                    @Html.LabelFor(model => model.customer.EmailId)                </td>                <td>                    @Html.TextBoxFor(model => model.customer.EmailId)                </td>            </tr>            <tr>                <td> </td>                <td>                    <input type="submit" value="保存" /> &nbsp; <a class="btn-primary" href="@Url.Action("Index ","Customer ")"> 返回 </a>                    @Html.HiddenFor(model => model.customer.CustomerId)                </td>            </tr>        </table>    }</div>

最终项目代码已经完成了。这时候我们运行项目试试看了。但还有一点要注意的是,我们必须同时运行web api和mvc项目。怎么办呢?其实只要在项目属性里设置就可以了。

  • 右键解决方案,选择属性(Properties)。

  • 接来下在启动项目选项中,选择多项目启动,在Action中设置两个项目同时启动。

  • 运行项目,看看CRUD操作的执行结果。

Select

Insert

Update

Delete

这是整个技术预研的过程,本文末尾位置提供代码下载。

 作者:阿子
 博客地址:http://www.cnblogs.com/yayazi/
 本文地址:http://www.cnblogs.com/yayazi/p/8444054.html
 声明:本博客原创文字允许转载,转载时必须保留此段声明,且在文章页面明显位置给出原文链接。
 源码下载:https://github.com/daivven/WebApiMVC

PS:本人近期打算换工作,目标地点武汉,目标职位.Net软件工程师,期望月薪资12k以上,春节后可参加面试。有没有园友有合适岗位推荐,私信我可发简历,求内推哇~

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