MVC 框架 - 高级示例

在第一章中,我们学习了控制器和视图如何在 MVC 中交互。在本教程中,我们将更进一步,学习如何使用模型并创建高级应用程序来创建、编辑、删除。并查看我们应用程序中的用户列表。

创建高级 MVC 应用程序

步骤 1 − 选择文件 → 新建 → 项目 → ASP.NET MVC Web 应用程序。将其命名为 AdvancedMVCApplication。单击确定。在下一个窗口中,选择 Internet 应用程序作为模板,Razor 作为视图引擎。请注意,我们这次使用的是模板,而不是空应用程序。

MVC New Internet Project

这将创建一个新的解决方案项目,如以下屏幕截图所示。由于我们使用默认的 ASP.NET 主题,它附带示例视图、控制器、模型和其他文件。

MVC 模型视图控制器

第 2 步 −构建解决方案并运行应用程序以查看其默认输出,如以下屏幕截图所示。

MVC 示例互联网应用程序

步骤 3 − 添加一个新模型,该模型将定义用户数据的结构。右键单击"模型"文件夹,然后单击"添加"→ 类。将其命名为 UserModel,然后单击"添加"。

MVC 添加模型步骤 1 MVC 添加模型步骤 2

步骤 4 −在新创建的UserModel.cs中复制以下代码。

using System; 
using System.ComponentModel; 
using System.ComponentModel.DataAnnotations; 
using System.Web.Mvc.Html;  

namespace AdvancedMVCApplication.Models { 
   public class UserModels { 
   
      [Required] 
      public int Id { get; set; } 
      [DisplayName("First Name")] 
      [Required(ErrorMessage = "First name is required")] 
      public string FirstName { get; set; }  
      [Required] 
      public string LastName { get; set; } 
         
      public string Address { get; set; } 
         
      [Required] 
      [StringLength(50)] 
      public string Email { get; set; } 
         
      [DataType(DataType.Date)] 
      public DateTime DOB { get; set; } 
         
      [Range(100,1000000)] 
      public decimal Salary { get; set; } 
   } 
} 

在上面的代码中,我们指定了 User 模型具有的所有参数、它们的数据类型和验证,例如必填字段和长度。

现在我们的 User 模型已准备好保存数据,我们将创建一个类文件 Users.cs,其中包含查看用户、添加、编辑和删除用户的方法。

步骤 5 − 右键单击​​ Models,然后单击 Add → Class。将其命名为 Users。这将在 Models 中创建 users.cs 类。将以下代码复制到 users.cs 类中。

using System; 
using System.Collections.Generic; 
using System.EnterpriseServices;  

namespace AdvancedMVCApplication.Models { 
   
   public class Users { 
      public List UserList = new List();  
      
      //action to get user details 
      public UserModels GetUser(int id) { 
         UserModels usrMdl = null;  
         
         foreach (UserModels um in UserList) 
            
            if (um.Id == id) 
               usrMdl = um; 
               return usrMdl; 
      }  
      
      //action to create new user 
      public void CreateUser(UserModels userModel) { 
         UserList.Add(userModel); 
      }  
      
      //action to udpate existing user 
      public void UpdateUser(UserModels userModel) { 
         
         foreach (UserModels usrlst in UserList) { 
            
            if (usrlst.Id == userModel.Id) { 
               usrlst.Address = userModel.Address; 
               usrlst.DOB = userModel.DOB; 
               usrlst.Email = userModel.Email; 
               usrlst.FirstName = userModel.FirstName; 
               usrlst.LastName = userModel.LastName; 
               usrlst.Salary = userModel.Salary; 
               break; 
            } 
         } 
      }  
      
      //action to delete exising user 
      public void DeleteUser(UserModels userModel) { 
         
         foreach (UserModels usrlst in UserList) { 
            
            if (usrlst.Id == userModel.Id) { 
               UserList.Remove(usrlst); 
               break; 
            } 
         } 
      } 
   } 
} 

一旦我们有了 UserModel.cs 和 Users.cs,我们将向模型添加视图,用于查看用户、添加、编辑和删除用户。首先让我们创建一个视图来创建用户。

步骤 6 − 右键单击​​ Views 文件夹,然后单击添加 → 视图。

mvc_advanced_add_view

步骤 7 −在下一个窗口中,选择视图名称为 UserAdd,视图引擎为 Razor,然后选中创建强类型视图复选框。

MVC Advanced User Add View

步骤 8 − 单击添加。这将默认创建以下 CSHML 代码,如下所示 −

@model AdvancedMVCApplication.Models.UserModels  

@{ 
   ViewBag.Title = "UserAdd"; 
}

<h2>UserAdd</h2>  

@using (Html.BeginForm()) { 
   @Html.ValidationSummary(true)  
   
   <fieldset> 
      <legend>UserModels</legend>  
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.FirstName) 
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.FirstName) 
         @Html.ValidationMessageFor(model => model.FirstName) 
      </div>  
      
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.LastName) 
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.LastName) 
         @Html.ValidationMessageFor(model => model.LastName) 
      </div>  
      
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.Address) 
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.Address) 
         @Html.ValidationMessageFor(model => model.Address) 
      </div>  
      
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.Email)
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.Email) 
         @Html.ValidationMessageFor(model => model.Email) 
      </div>  
      
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.DOB) 
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.DOB) 
         @Html.ValidationMessageFor(model => model.DOB) 
      </div>  
      
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.Salary) 
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.Salary) 
         @Html.ValidationMessageFor(model => model.Salary) 
      </div>  
      
      <p> 
         <input type = "submit" value = "Create" /> 
      </p> 
   </fieldset> 
}  
<div> 
   @Html.ActionLink("Back to List", "Index") 
</div>  

@section Scripts { 
   
   @Scripts.Render("~/bundles/jqueryval") 
}

如您所见,此视图包含字段的所有属性的视图详细信息,包括其验证消息、标签等。此视图在我们的最终应用程序中将如下所示。

MVC Advanced Application 1

与 UserAdd 类似,现在我们将使用给定的代码 − 添加下面给出的另外四个视图

Index.cshtml

此视图将在 Index 页面上显示我们系统中存在的所有用户。

@model IEnumerable<AdvancedMVCApplication.Models.UserModels>  

@{ 
   ViewBag.Title = "Index"; 
}  

<h2>Index</h2>  

<p> 
   @Html.ActionLink("Create New", "UserAdd") 
</p>  

<table> 
   <tr> 
      <th> 
         @Html.DisplayNameFor(model => model.FirstName) 
      </th> 
   
      <th> 
         @Html.DisplayNameFor(model => model.LastName) 
      </th> 
   
      <th> 
         @Html.DisplayNameFor(model => model.Address) 
      </th> 
   
      <th> 
         @Html.DisplayNameFor(model => model.Email) 
      </th> 
   
      <th> 
         @Html.DisplayNameFor(model => model.DOB) 
      </th> 
   
      <th> 
         @Html.DisplayNameFor(model => model.Salary) 
      </th> 
   
      <th></th>  
   </tr>  
   
   @foreach (var item in Model) { 
      <tr> 
         <td>
            @Html.DisplayFor(modelItem => item.FirstName) 
         </td> 
    
         <td> 
            @Html.DisplayFor(modelItem => item.LastName) 
         </td> 
    
         <td> 
            @Html.DisplayFor(modelItem => item.Address) 
         </td> 
    
         <td> 
            @Html.DisplayFor(modelItem => item.Email) 
         </td> 
    
         <td> 
            @Html.DisplayFor(modelItem => item.DOB) 
         </td> 
    
         <td> 
            @Html.DisplayFor(modelItem => item.Salary) 
         </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>

此视图在我们的最终应用程序中将如下所示。

MVC Advanced Application 2

Details.cshtml

当我们单击用户记录时,此视图将显示特定用户的详细信息。

@model AdvancedMVCApplication.Models.UserModels  

@{ 
   ViewBag.Title = "Details"; 
}  

<h2>Details</h2>  
<fieldset> 
   <legend>UserModels</legend>  
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.FirstName) 
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.FirstName) 
   </div>  
   
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.LastName) 
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.LastName)
   </div>  
   
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.Address) 
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.Address) 
   </div>  
   
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.Email) 
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.Email) 
   </div>  
    
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.DOB) 
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.DOB) 
   </div>  
   
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.Salary) 
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.Salary) 
   </div> 
  
</fieldset>  
<p>
   @Html.ActionLink("Edit", "Edit", new { id = Model.Id }) | 
   @Html.ActionLink("Back to List", "Index") 
</p>

此视图在我们的最终应用程序中将如下所示。

MVC Advanced Application Details

Edit.cshtml

此视图将显示编辑表单以编辑现有用户的详细信息。

@model AdvancedMVCApplication.Models.UserModels  

@{ 
   ViewBag.Title = "Edit"; 
}  

<h2>Edit</h2>  
@using (Html.BeginForm()) { 
   @Html.AntiForgeryToken() 
   @Html.ValidationSummary(true)  
   
   <fieldset> 
      <legend>UserModels</legend>  
      @Html.HiddenFor(model => model.Id)  
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.FirstName) 
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.FirstName) 
         @Html.ValidationMessageFor(model => model.FirstName) 
      </div>  
      
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.LastName) 
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.LastName) 
         @Html.ValidationMessageFor(model => model.LastName) 
      </div>  
      
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.Address) 
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.Address) 
         @Html.ValidationMessageFor(model => model.Address) 
      </div>  
      
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.Email) 
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.Email) 
         @Html.ValidationMessageFor(model => model.Email) 
      </div>  
      
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.DOB)
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.DOB) 
         @Html.ValidationMessageFor(model => model.DOB) 
      </div>  
      
      <div class = "editor-label"> 
         @Html.LabelFor(model => model.Salary) 
      </div> 
   
      <div class = "editor-field"> 
         @Html.EditorFor(model => model.Salary) 
         @Html.ValidationMessageFor(model => model.Salary) 
      </div>  
      
      <p> 
         <input type = "submit" value = "Save" /> 
      </p> 
   </fieldset> 
}  
<div> 
   @Html.ActionLink("Back to List", "Index") 
</div>  

@section Scripts { 
   @Scripts.Render("~/bundles/jqueryval") 
}

此视图在我们的应用程序中将如下所示。

MVC Advanced Application Details

Delete.cshtml

此视图将显示删除现有用户的表单。

@model AdvancedMVCApplication.Models.UserModels  

@{ 
   ViewBag.Title = "Delete"; 
} 

<h2>Delete</h2>  
<h3>Are you sure you want to delete this?</h3>  
<fieldset> 
   <legend>UserModels</legend>  
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.FirstName) 
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.FirstName) 
   </div>  
   
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.LastName) 
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.LastName) 
   </div>  
   
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.Address) 
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.Address) 
   </div>  
   
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.Email) 
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.Email) 
   </div>  
   
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.DOB) 
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.DOB) 
   </div>  
   
   <div class = "display-label"> 
      @Html.DisplayNameFor(model => model.Salary)
   </div> 
  
   <div class = "display-field"> 
      @Html.DisplayFor(model => model.Salary) 
   </div> 
</fieldset>  

@using (Html.BeginForm()) { 
   @Html.AntiForgeryToken() 
   
   <p> 
      <input type = "submit" value = "Delete" /> | 
      @Html.ActionLink("Back to List", "Index") 
   </p> 
}

此视图在我们的最终应用程序中将如下所示。

MVC advanced Application Details Delete

第 9 步 − 我们已经在应用程序中添加了模型和视图。现在我们终于可以为视图添加一个控制器了。右键单击 Controllers 文件夹,然后单击 Add → Controller。将其命名为 UserController。

MVC Advanced Add Controller

默认情况下,您的 Controller 类将使用以下代码创建 −

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.Mvc; 
using AdvancedMVCApplication.Models;  

namespace AdvancedMVCApplication.Controllers {  
   
   public class UserController : Controller { 
      private static Users _users = new Users(); 
      
      public ActionResult Index() { 
         return View(_users.UserList); 
      } 
   } 
} 

在上面的代码中,Index 方法将在 Index 页面上呈现用户列表时使用。

步骤 10 − 右键单击​​ Index 方法并选择"创建视图"以创建 Index 页面的视图(它将列出所有用户并提供创建新用户的选项)。

MVC Advanced add Index View

步骤 11 − 现在在 UserController.cs 中添加以下代码。在此代码中,我们为不同的用户操作创建操作方法并返回我们之前创建的相应视图。

我们将为每个操作添加两种方法:GET 和 POST。HttpGet 将在获取数据并呈现数据时使用。HttpPost 将用于创建/更新数据。例如,当我们添加新用户时,我们需要一个表单来添加用户,这是一个 GET 操作。填写表单并提交这些值后,我们将需要 POST 方法。

//索引视图的操作  
public ActionResult Index() { 
   return View(_users.UserList); 
}  

//UserAdd 视图的操作
[HttpGet]
public ActionResult UserAdd() {
    return View();
}

[HttpPost]
public ActionResult UserAdd(UserModels userModel) {
    _users.CreateUser(userModel);
    r​​eturn View("Index", _users.UserList);
}

//Details 视图的操作
[HttpGet]
public ActionResult Details(int id) {
    return View(_users.UserList.FirstOrDefault(x => x.Id == id));
}

[HttpPost]
public ActionResult Details() {
    return View("Index", _users.UserList);
}

//Edit 视图的操作
[HttpGet]
public ActionResult Edit(int id) {
    return View(_users.UserList.FirstOrDefault(x=>x.Id==id));
}

[HttpPost]
public ActionResult Edit(UserModels userModel) {
    _users.UpdateUser(userModel);
    r​​eturn View("Index", _users.UserList);
}

//删除视图的操作
[HttpGet] 
public ActionResult Delete(int id) { 
   return View(_users.UserList.FirstOrDefault(x => x.Id == id)); 
}  

[HttpPost] 
public ActionResult Delete(UserModels userModel) { 
   _users.DeleteUser(userModel); 
   return View("Index", _users.UserList); 
} sers.UserList);

步骤 12 − 最后一件事是转到 App_Start 文件夹中的 RouteConfig.cs 文件并将默认控制器更改为 User。

defaults: new { controller = "User", action = "Index", id = UrlParameter.Optional }

这就是我们启动和运行高级应用程序所需的全部内容。

步骤 13 − 现在运行该应用程序。您将能够看到如以下屏幕截图所示的应用程序。您可以执行我们在之前的屏幕截图中看到的所有添加、查看、编辑和删除用户的功能。

MVC Advanced Add Index Final