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ASP.NET - WF模型绑定

ASP.NET - WF模型绑定

本主题说明如何使用模型绑定和Web窗体处理数据。与处理ObjectDataSource或SqlDataSource等数据源对象相比，模型绑定使数据交互更加直接。

在本教程中，无涯教程将使用Entity Framework for Data和GridView在网页上显示数据。在这里，正在创建一个包括以下步骤的示例。

创建ASP.NET Web应用程序

ASP Model building 1

选择模板

选择模板作为Web表单，并将身份验证更改为单个用户帐户。

ASP Model building 2

创建主页

使用母版页模板创建新的Web表单。将使用此母版页显示模型数据。

ASP Model building 3

创建数据模型和数据库

将使用代码优先迁移来创建对象和相应的数据库表。这些表将存储有关学生及其课程的信息。

在Model文件夹中创建一个新的模型类。

//StudentModels.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;
using System.ComponentModel.DataAnnotations;
namespace ModelBindingDemo.Models
{
public class SchoolContextDemo : DbContext
    {
public DbSet<Student> Students { get; set; }
public DbSet<Enrollment> Enrollments { get; set; }
public DbSet<Course> Courses { get; set; }
    }
public class Student
    {
        [Key, Display(Name = "Email ID")]
        [ScaffoldColumn(false)]
public int StudentID { get; set; }
        [Required, StringLength(40), Display(Name = "Last Name")]
public string LastName { get; set; }
        [Required, StringLength(20), Display(Name = "First Name")]
public string FirstName { get; set; }
        [Required, StringLength(50), Display(Name = "Email ID")]
public string Email { get; set; }
        [EnumDataType(typeof(AcademicYear)), Display(Name = "Academic Year")]
public AcademicYear Year { get; set; }
public virtual ICollection<Enrollment> Enrollments { get; set; }
    }
public class Enrollment
    {
        [Key]
public int EnrollmentID { get; set; }
public int CourseID { get; set; }
public int StudentID { get; set; }
public decimal? Grade { get; set; }
public virtualCourse Course { get; set; }
public virtualStudent Student { get; set; }
    }
public class Course
    {
        [Key]
public int CourseID { get; set; }
public string Title { get; set; }
public int Credits { get; set; }
public virtual ICollection<Enrollment> Enrollments { get; set; }
    }
public enum AcademicYear
    {
        Freshman,
        Sophomore,
        Junior,
        Senior
    }
}

SchoolContextDemo类派生自DbContext，后者管理数据库连接和数据更改。

将使用代码优先迁移工具来设置基于这些类的数据库。按照view->other windows-> Package Manager Console。

它将在Visual Studio IDE的底部提示一个屏幕。需要在此控制台中执行以下命令。

enable-migrations -Force -ContextTypeName ModelBindingDemo.Models.SchoolContextDemo

执行上述命令后，它将生成以下输出。

ASP Model building 4

之后，将创建名为Configuration.cs的新文件。此文件在创建后会自动打开。

在配置文件中添加测试数据

在这里，将向配置文件添加一些数据，以便在网页上显示给用户。将数据添加到文件后，Configuration.cs文件如下所示：

//Configuration.cs

namespace ModelBindingDemo.Migrations
{
using System;
using System.Data.Entity;
using System.Data.Entity.Migrations;
using System.Linq;
using ModelBindingDemo.Models;
internal sealed class Configuration : DbMigrationsConfiguration<ModelBindingDemo.Models.SchoolContextDemo>
    {
public Configuration()
        {
            AutomaticMigrationsEnabled = false;
        }
protected override void Seed(ModelBindingDemo.Models.SchoolContextDemo context)
        {
            context.Students.AddOrUpdate(
new Student
                 {
                     FirstName = "M. Irfan",
                     LastName = "Khan",
                     Email = "irfan@example.com",
                     Year = AcademicYear.Freshman
                 },
new Student
                 {
                     FirstName = "Arvind",
                     LastName = "Kumar",
                     Email = "Arvind@example.com",
                     Year = AcademicYear.Freshman
                 },
new Student
                 {
                     FirstName = "Arturo",
                     LastName = "Anand",
                     Email = "Anand@example.com",
                     Year = AcademicYear.Sophomore
                 },
new Student
                 {
                     FirstName = "Moris",
                     LastName = "Mano",
                     Email = "moris@example.com",
                     Year = AcademicYear.Sophomore
                 },
new Student
                 {
                     FirstName = "Roman",
                     LastName = "Sigh",
                     Email = "roman@example.com",
                     Year = AcademicYear.Junior
                 },
new Student
                 {
                     FirstName = "Jimmi",
                     LastName = "Seth",
                     Email = "jimmi@example.com",
                     Year = AcademicYear.Junior
                 },
new Student
                 {
                     FirstName = "Shayam",
                     LastName = "Rana",
                     Email = "Shayam@example.com",
                     Year = AcademicYear.Senior
                 },
new Student
                 {
                     FirstName = "Jecub",
                     LastName = "Cunto",
                     Email = "Nino@example.com",
                     Year = AcademicYear.Senior
                 }
                 );
         context.SaveChanges();
            context.Courses.AddOrUpdate(
new Course { Title = "Chemistry", Credits = 3 },
new Course { Title = "Microeconomics", Credits = 3 },
new Course { Title = "Macroeconomics", Credits = 3 },
new Course { Title = "Calculus", Credits = 4 },
new Course { Title = "Trigonometry", Credits = 4 },
new Course { Title = "Composition", Credits = 3 },
new Course { Title = "Literature", Credits = 4 }
                );
         context.SaveChanges();
            context.Enrollments.AddOrUpdate(
new Enrollment { StudentID = 1, CourseID = 1, Grade = 1 },
new Enrollment { StudentID = 1, CourseID = 2, Grade = 3 },
new Enrollment { StudentID = 1, CourseID = 3, Grade = 1 },
new Enrollment { StudentID = 2, CourseID = 4, Grade = 2 },
new Enrollment { StudentID = 2, CourseID = 5, Grade = 4 },
new Enrollment { StudentID = 2, CourseID = 6, Grade = 4 },
new Enrollment { StudentID = 3, CourseID = 1 },
new Enrollment { StudentID = 4, CourseID = 1 },
new Enrollment { StudentID = 4, CourseID = 2, Grade = 4 },
new Enrollment { StudentID = 5, CourseID = 3, Grade = 3 },
new Enrollment { StudentID = 6, CourseID = 4 },
new Enrollment { StudentID = 7, CourseID = 5, Grade = 2 }
                );
         context.SaveChanges();
        }
    }
}

之后，在package Manager控制台中，运行以下命令。

PM> add-migration initial

和

PM> update-database

ASP Model building 5

现在，已经创建了一个数据库，并将其添加到App_Data文件夹下的项目中。

现在，将创建的数据库中的数据显示到网页上。将使用GridView控件以网格形式显示数据。Student.aspx文件如下所示：

//Student.aspx

<%@PageTitle="" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" 
CodeBehind="Students.aspx.cs" Inherits="ModelBindingDemo.Students" %>
<asp:ContentID="Content1"ContentPlaceHolderID="MainContent"runat="server">
<asp:GridViewrunat="server"ID="studentsGrid"
ItemType="ModelBindingDemo.Models.Student"DataKeyNames="StudentID"
SelectMethod="studentsGrid_GetData"
AutoGenerateColumns="false">
<Columns>
<asp:DynamicFieldDataField="StudentID"/>
<asp:DynamicFieldDataField="FirstName"/>
<asp:DynamicFieldDataField="LastName"/>
<asp:DynamicFieldDataField="Email"/>
</Columns>
</asp:GridView>
</asp:Content>

//Student.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using ModelBindingDemo.Models;
using System.Data.Entity;
namespace ModelBindingDemo
{
public partial class Students : System.Web.UI.Page
    {
protected void Page_Load(object sender, EventArgs e)
        {
        }
public IQueryable<Student> studentsGrid_GetData()
        {
SchoolContextDemo db = newSchoolContextDemo();
var query = db.Students.Include(s => s.Enrollments.Select(e => e.Course));
return query;
        }
    }
}

最后，无涯教程的项目如下所示。

ASP Model building 6

输出：

在浏览器中以视图形式运行Student.aspx文件，将产生以下输出。

ASP Model building 7

祝学习愉快！(内容编辑有误？请选中要编辑内容 -> 右键 -> 修改 -> 提交！)

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