WPF开发学生信息管理系统【WPF+Prism+MAH+WebApi】（二）

最近通过WPF开发项目，为了对WPF知识点进行总结，所以利用业余时间，开发一个学生信息管理系统【Student Information Management System】。上一篇文章进行了框架搭建和模块划分，本文在前一篇基础之上，继续深入开发学生信息管理系统的数据库和WebApi接口搭建相关内容，仅供学习分享使用，如有不足之处，还请指正。

涉及知识点

本篇内容主要是数据库的操作和WebApi的创建，涉及到知识点如下所示：

  • 数据库知识，基于SQL Server 2012的数据表创建，以及CRUD【(Create)、检索(Retrieve)、更新(Update)和删除(Delete)】等基础操作。
  • WebApi接口创建基础操作，本文会涉及到通过WebApi提供数据接口给客户端，用于封装数据持久化的操作。

数据库相关

在学生信息管理系统中，学生，班级，课程，成绩等内容和管理模块的相关内容，都离不开数据库的支持，所以数据是支撑，页面是对数据的展示。数据库结构，如下所示：

 

主要涉及的表如下所示：

1. 学生表Student

学生表主要存储学生的基础信息，如下所示：

 

学生表创建语句，如下所示：

 1 USE [SIMS]
 2 GO
 3 
 4 /****** Object:  Table [dbo].[Students]    Script Date: 2022/5/25 0:11:41 ******/
 5 SET ANSI_NULLS ON
 6 GO
 7 
 8 SET QUOTED_IDENTIFIER ON
 9 GO
10 
11 SET ANSI_PADDING ON
12 GO
13 
14 CREATE TABLE [dbo].[Students](
15     [Id] [int] IDENTITY(1,1) NOT NULL,
16     [No] [varchar](50) NULL,
17     [Name] [varchar](50) NULL,
18     [Age] [int] NULL,
19     [Sex] [bit] NULL,
20     [ClassesId] [int] NULL,
21     [CreateUser] [int] NULL,
22     [CreateTime] [datetime] NULL,
23     [LastEditUser] [int] NULL,
24     [LastEditTime] [datetime] NULL
25 ) ON [PRIMARY]
26 
27 GO
28 
29 SET ANSI_PADDING OFF
30 GO

2. 班级表Classes

班级表主要用于保存班级相关信息，如下所示：

 

 班级表创建语句，如下所示：

 1 USE [SIMS]
 2 GO
 3 
 4 /****** Object:  Table [dbo].[Classes]    Script Date: 2022/5/25 0:16:31 ******/
 5 SET ANSI_NULLS ON
 6 GO
 7 
 8 SET QUOTED_IDENTIFIER ON
 9 GO
10 
11 SET ANSI_PADDING ON
12 GO
13 
14 CREATE TABLE [dbo].[Classes](
15     [Id] [int] IDENTITY(1,1) NOT NULL,
16     [Name] [varchar](50) NULL,
17     [Dept] [varchar](50) NULL,
18     [Grade] [varchar](50) NULL,
19     [HeadTeacher] [varchar](50) NULL,
20     [Monitor] [int] NULL,
21     [CreateUser] [int] NULL,
22     [CreateTime] [datetime] NULL,
23     [LastEditUser] [int] NULL,
24     [LastEditTime] [datetime] NULL
25 ) ON [PRIMARY]
26 
27 GO
28 
29 SET ANSI_PADDING OFF
30 GO

3. 课程表Courses

课程表主要保存课程信息，如下所示：

 

 课程表创建语句，如下所示：

 1 USE [SIMS]
 2 GO
 3 
 4 /****** Object:  Table [dbo].[Courses]    Script Date: 2022/5/25 0:20:11 ******/
 5 SET ANSI_NULLS ON
 6 GO
 7 
 8 SET QUOTED_IDENTIFIER ON
 9 GO
10 
11 SET ANSI_PADDING ON
12 GO
13 
14 CREATE TABLE [dbo].[Courses](
15     [Id] [int] IDENTITY(1,1) NOT NULL,
16     [Name] [varchar](50) NULL,
17     [Teacher] [varchar](50) NULL,
18     [CreateUser] [int] NULL,
19     [CreateTime] [datetime] NULL,
20     [LastEditUser] [int] NULL,
21     [LastEditTime] [datetime] NULL
22 ) ON [PRIMARY]
23 
24 GO
25 
26 SET ANSI_PADDING OFF
27 GO

4. 成绩表Scores

成绩表用于保存学生各科的成绩，如下所示：

 

 成绩表创建语句，如下所示：

 1 USE [SIMS]
 2 GO
 3 
 4 /****** Object:  Table [dbo].[Scores]    Script Date: 2022/5/25 0:23:19 ******/
 5 SET ANSI_NULLS ON
 6 GO
 7 
 8 SET QUOTED_IDENTIFIER ON
 9 GO
10 
11 CREATE TABLE [dbo].[Scores](
12     [Id] [int] IDENTITY(1,1) NOT NULL,
13     [StudentId] [int] NULL,
14     [CourseId] [int] NULL,
15     [Score] [float] NULL,
16     [CreateUser] [int] NULL,
17     [CreateTime] [datetime] NULL,
18     [LastEditUser] [int] NULL,
19     [LastEditTime] [datetime] NULL
20 ) ON [PRIMARY]
21 
22 GO

5. 其他数据表

其他数据表包括用户表【Users】，角色表【Roles】，用户角色对应关系表【UserRoles】，角色菜单对应关系表【RoleMenus】菜单表【Menus】 创建语句，如下所示：

  1 USE [SIMS]
  2 GO
  3 
  4 /****** Object:  Table [dbo].[Users]    Script Date: 2022/5/25 0:29:55 ******/
  5 SET ANSI_NULLS ON
  6 GO
  7 
  8 SET QUOTED_IDENTIFIER ON
  9 GO
 10 
 11 SET ANSI_PADDING ON
 12 GO
 13 
 14 CREATE TABLE [dbo].[Users](
 15     [Id] [int] IDENTITY(1,1) NOT NULL,
 16     [UserName] [varchar](50) NULL,
 17     [Password] [varchar](50) NULL,
 18     [NickName] [varchar](50) NULL
 19 ) ON [PRIMARY]
 20 
 21 GO
 22 
 23 SET ANSI_PADDING OFF
 24 GO
 25 ------------------------------------------
 26 USE [SIMS]
 27 GO
 28 
 29 /****** Object:  Table [dbo].[Roles]    Script Date: 2022/5/25 0:30:21 ******/
 30 SET ANSI_NULLS ON
 31 GO
 32 
 33 SET QUOTED_IDENTIFIER ON
 34 GO
 35 
 36 SET ANSI_PADDING ON
 37 GO
 38 
 39 CREATE TABLE [dbo].[Roles](
 40     [id] [int] IDENTITY(1,1) NOT NULL,
 41     [Name] [varchar](50) NULL,
 42     [Description] [varchar](50) NULL
 43 ) ON [PRIMARY]
 44 
 45 GO
 46 
 47 SET ANSI_PADDING OFF
 48 GO
 49 ------------------------------------------
 50 USE [SIMS]
 51 GO
 52 
 53 /****** Object:  Table [dbo].[Menus]    Script Date: 2022/5/25 0:31:04 ******/
 54 SET ANSI_NULLS ON
 55 GO
 56 
 57 SET QUOTED_IDENTIFIER ON
 58 GO
 59 
 60 SET ANSI_PADDING ON
 61 GO
 62 
 63 CREATE TABLE [dbo].[Menus](
 64     [id] [int] IDENTITY(1,1) NOT NULL,
 65     [Name] [varchar](50) NULL,
 66     [Description] [varchar](50) NULL,
 67     [Url] [varchar](250) NULL,
 68     [ParentId] [int] NULL,
 69     [SortId] [int] NULL
 70 ) ON [PRIMARY]
 71 
 72 GO
 73 
 74 SET ANSI_PADDING OFF
 75 GO
 76 
 77 ------------------------------------------
 78 USE [SIMS]
 79 GO
 80 
 81 /****** Object:  Table [dbo].[UserRoles]    Script Date: 2022/5/25 0:31:20 ******/
 82 SET ANSI_NULLS ON
 83 GO
 84 
 85 SET QUOTED_IDENTIFIER ON
 86 GO
 87 
 88 CREATE TABLE [dbo].[UserRoles](
 89     [id] [int] IDENTITY(1,1) NOT NULL,
 90     [UserId] [int] NULL,
 91     [RoleId] [int] NULL
 92 ) ON [PRIMARY]
 93 
 94 GO
 95 ------------------------------------------
 96 USE [SIMS]
 97 GO
 98 
 99 /****** Object:  Table [dbo].[RoleMenus]    Script Date: 2022/5/25 0:31:35 ******/
100 SET ANSI_NULLS ON
101 GO
102 
103 SET QUOTED_IDENTIFIER ON
104 GO
105 
106 CREATE TABLE [dbo].[RoleMenus](
107     [id] [int] IDENTITY(1,1) NOT NULL,
108     [RoleId] [int] NULL,
109     [MenuId] [int] NULL
110 ) ON [PRIMARY]
111 
112 GO
View Code

数据库实体类

数据库实体类是数据库表与类的映射，通过操作实体类来达到操作数据库的目的，实体类需要与EntityFramework结合起来使用。如下所示：

1. 学生类StudentEntity

学生类与学生表对应，如下所示：

 1 namespace SIMS.Entity
 2 {
 3     /// <summary>
 4     /// 学生实体
 5     /// </summary>
 6     public class StudentEntity
 7     {
 8         /// <summary>
 9         /// 唯一标识
10         /// </summary>
11         public int Id { get; set; }
12 
13         /// <summary>
14         /// 学号
15         /// </summary>
16         public string No { get; set; }
17 
18         /// <summary>
19         /// 学生名称
20         /// </summary>
21         public string Name { get; set; }
22 
23         /// <summary>
24         /// 年纪
25         /// </summary>
26         public int Age { get; set; }
27 
28         /// <summary>
29         /// 性别
30         /// </summary>
31         public Boolean Sex { get; set; }
32 
33         /// <summary>
34         /// 班级标识
35         /// </summary>
36         public int? ClassesId { get; set; }
37 
38         /// <summary>
39         /// 创建时间
40         /// </summary>
41         public DateTime? CreateTime { get; set; }
42 
43         /// <summary>
44         /// 当前登录的账号的ID
45         /// </summary>
46         public int? CreateUser { get; set; }
47 
48         /// <summary>
49         /// 最后编辑时间
50         /// </summary>
51         public DateTime? LastEditTime { get; set; }
52 
53         /// <summary>
54         /// 最后修改人
55         /// </summary>
56         public int? LastEditUser { get; set; }
57     }
58 }

2. 班级类ClassesEntity

班级类与班级表对应，如下所示：

 1 namespace SIMS.Entity
 2 {
 3     /// <summary>
 4     /// 班级实体
 5     /// </summary>
 6     public class ClassesEntity
 7     {
 8         /// <summary>
 9         /// 唯一标识
10         /// </summary>
11         public int Id { get; set; }
12 
13         /// <summary>
14         /// 专业
15         /// </summary>
16         public string Dept { get; set; }
17 
18         /// <summary>
19         /// 年级
20         /// </summary>
21         public string Grade { get; set; }
22 
23         /// <summary>
24         /// 班级名称
25         /// </summary>
26         public string Name { get; set; }
27 
28         /// <summary>
29         /// 班主任老师名称
30         /// </summary>
31         public string HeadTeacher { get; set; }
32 
33         /// <summary>
34         /// 班长id，对应学生表的学生
35         /// </summary>
36         public int? Monitor { get; set; }
37 
38         /// <summary>
39         /// 创建时间
40         /// </summary>
41         public DateTime CreateTime { get; set; }
42 
43         /// <summary>
44         /// 当前登录的账号的ID
45         /// </summary>
46         public int CreateUser { get; set; }
47 
48         /// <summary>
49         /// 最后编辑时间
50         /// </summary>
51         public DateTime LastEditTime { get; set; }
52 
53         /// <summary>
54         /// 最后修改人
55         /// </summary>
56         public int LastEditUser { get; set; }
57     }
58 }

3. 课程类CourseEntity

课程类与课程表对应，如下所示：

 1 namespace SIMS.Entity
 2 {
 3     /// <summary>
 4     /// 课程实体
 5     /// </summary>
 6     public class CourseEntity
 7     {
 8         /// <summary>
 9         /// 唯一标识
10         /// </summary>
11         public int Id { get; set; }
12 
13         /// <summary>
14         /// 课程名称
15         /// </summary>
16         public string Name { get; set; }
17 
18         /// <summary>
19         /// 授课老师
20         /// </summary>
21         public string Teacher { get; set; }
22 
23         /// <summary>
24         /// 创建时间
25         /// </summary>
26         public DateTime CreateTime { get; set; }
27 
28         /// <summary>
29         /// 当前登录的账号的ID
30         /// </summary>
31         public int CreateUser { get; set; }
32 
33         /// <summary>
34         /// 最后编辑时间
35         /// </summary>
36         public DateTime LastEditTime { get; set; }
37 
38         /// <summary>
39         /// 最后修改人
40         /// </summary>
41         public int LastEditUser { get; set; } 
42     }
43 }

4. 成绩类ScoreEntity

成绩类与成绩表对应，如下所示：

 1 namespace SIMS.Entity
 2 {
 3     /// <summary>
 4     /// 成绩实体
 5     /// </summary>
 6     public class ScoreEntity
 7     {
 8         /// <summary>
 9         /// 唯一标识
10         /// </summary>
11         public int Id { get; set; }
12 
13         /// <summary>
14         ///学生id
15         /// </summary>
16         public int StudentId { get; set; }
17 
18         /// <summary>
19         /// 课程id
20         /// </summary>
21         public int CourseId { get; set; }
22 
23         /// <summary>
24         /// 成绩
25         /// </summary>
26         public double Score { get; set; }
27 
28         /// <summary>
29         /// 创建时间
30         /// </summary>
31         public DateTime CreateTime { get; set; }
32 
33         /// <summary>
34         /// 当前登录的账号的ID
35         /// </summary>
36         public int CreateUser { get; set; }
37 
38         /// <summary>
39         /// 最后编辑时间
40         /// </summary>
41         public DateTime LastEditTime { get; set; }
42 
43         /// <summary>
44         /// 最后修改人
45         /// </summary>
46         public int LastEditUser { get; set; }
47     }
48 }

5. 其他实体类

除了以上四个主要的实体类，还有其他实体类，如下所示：

菜单实体MenuEntity，如下所示：

 1 namespace SIMS.Entity
 2 {
 3     /// <summary>
 4     /// 菜单管理
 5     /// </summary>
 6     public class MenuEntity
 7     {
 8         /// <summary>
 9         /// 唯一标识
10         /// </summary>
11         public int Id { get; set; }
12 
13         /// <summary>
14         /// 菜单名称
15         /// </summary>
16         public string Name { get; set; }
17 
18         /// <summary>
19         /// 菜单描述
20         /// </summary>
21         public string Description { get; set; }
22 
23         /// <summary>
24         /// 菜单路径
25         /// </summary>
26         public string Url { get; set; }
27 
28         /// <summary>
29         /// 父ID
30         /// </summary>
31         public int? ParentId { get; set; }
32 
33         /// <summary>
34         /// 排序
35         /// </summary>
36         public int? SortId { get; set; }
37     }
38 }
View Code

用户实体类UserEntity，如下所示：

 1 namespace SIMS.Entity
 2 {
 3     public class UserEntity
 4     {
 5         /// <summary>
 6         /// 用户唯一标识
 7         /// </summary>
 8         public int Id { get; set; }
 9 
10         /// <summary>
11         /// 登录账号
12         /// </summary>
13         public string UserName { get; set; }
14 
15         /// <summary>
16         /// 密码
17         /// </summary>
18         public string Password { get; set; }
19 
20         /// <summary>
21         /// 显示名称
22         /// </summary>
23         public string NickName { get; set; }
24     }
25 }
View Code

角色实体类RoleEntity，如下所示：

 1 namespace SIMS.Entity
 2 {
 3     /// <summary>
 4     /// 角色
 5     /// </summary>
 6     public class RoleEntity
 7     {
 8         /// <summary>
 9         /// 唯一标识
10         /// </summary>
11         public int Id { get; set; }
12 
13         /// <summary>
14         /// 角色名称
15         /// </summary>
16         public string Name { get; set; }
17 
18         /// <summary>
19         /// 角色描述
20         /// </summary>
21         public string Description { get; set; }
22     }
23 }
View Code

用户角色关系实体类UserRoleEntityr，如下所示：

 1 namespace SIMS.Entity
 2 {
 3     /// <summary>
 4     /// 用户-角色模型
 5     /// </summary>
 6     public class UserRoleEntity
 7     {
 8         /// <summary>
 9         /// 唯一标识
10         /// </summary>
11         public int Id { get; set; }
12 
13         /// <summary>
14         /// 用户ID
15         /// </summary>
16         public int UserId { get; set; }
17 
18         /// <summary>
19         /// 角色ID
20         /// </summary>
21         public int RoleId { get; set; }
22     }
23 }
View Code

角色菜单关系实体RoleMenuEntity，如下所示：

 1 namespace SIMS.Entity
 2 {
 3     /// <summary>
 4     /// 角色-菜单关联
 5     /// </summary>
 6     public class RoleMenuEntity
 7     {
 8         /// <summary>
 9         /// 唯一标识
10         /// </summary>
11         public int Id { get; set; }
12 
13         /// <summary>
14         /// 菜单IP
15         /// </summary>
16         public int MenuId { get; set; }
17 
18         /// <summary>
19         /// 角色ID
20         /// </summary>
21         public int RoleId { get; set; }
22     }
23 }
View Code

一共九个实体类，对应数据库中的九个表。

WebApi数据接口

在本示例中，客户端和服务端交互通过webapi接口进行，避免直接操作数据库。具体步骤如下所示：

1. EntityFramework框架

EntityFramework是.Net领域通用的ORM框架，有CodeFirst和DBFirst两种方式，本文采用DBFirst方式，即先设计数据库表结构，再创建实体和映射。如果要使用EntityFramework框架，首先进行安装，可通过NuGet包管理器进行安装，如下所示：

 

 创建DataContext数据操作类，继承自DbContext，并重写OnModelCreating方法，将数据表和实体类建立联系，实现映射，如下所示：

 1 namespace SIMS.WebApi.Data
 2 {
 3     public class DataContext:DbContext
 4     {
 5         public DbSet<UserEntity> Users { get; set; }
 6 
 7         public DbSet<MenuEntity> Menus { get; set; }
 8 
 9         public DbSet<RoleEntity> Roles { get; set; }
10 
11         public DbSet<UserRoleEntity> UserRoles { get; set; }
12 
13         public DbSet<RoleMenuEntity> RoleMenus { get; set; }
14 
15         /// <summary>
16         /// 学生
17         /// </summary>
18         public DbSet<StudentEntity> Students { get; set; }
19 
20         /// <summary>
21         /// 班级
22         /// </summary>
23         public DbSet<ClassesEntity> Classes { get; set; }
24 
25         /// <summary>
26         /// 课程
27         /// </summary>
28         public DbSet<CourseEntity> Courses { get; set; }
29 
30         /// <summary>
31         /// 成绩
32         /// </summary>
33         public DbSet<ScoreEntity> Scores { get; set; }
34 
35         public DataContext(DbContextOptions options) : base(options)
36         {
37 
38         }
39 
40         protected override void OnModelCreating(ModelBuilder modelBuilder)
41         {
42             base.OnModelCreating(modelBuilder);
43             modelBuilder.Entity<UserEntity>().ToTable("Users");
44             modelBuilder.Entity<MenuEntity>().ToTable("Menus");
45             modelBuilder.Entity<StudentEntity>().ToTable("Students");
46             modelBuilder.Entity<RoleEntity>().ToTable("Roles");
47             modelBuilder.Entity<UserRoleEntity>().ToTable("UserRoles");
48             modelBuilder.Entity<RoleMenuEntity>().ToTable("RoleMenus");
49         }
50     }
51 }

2. 创建服务

在本示例中，为了封装数据库的底层操作，提取了四个服务接口和类，如下所示：

学生服务接口IStudentAppService，是对学生表操作的封装，如下所示：

 1 namespace SIMS.WebApi.Services.Student
 2 {
 3     public interface IStudentAppService
 4     {
 5         /// <summary>
 6         /// 查询学生列表
 7         /// </summary>
 8         /// <param name="name"></param>
 9         /// <returns></returns>
10         public PagedRequest<StudentEntity> GetStudents(string no,string name, int pageNum, int pageSize);
11 
12         /// <summary>
13         /// 查询某一班级的学生列表
14         /// </summary>
15         /// <param name="classId"></param>
16         /// <returns></returns>
17         public PagedRequest<StudentEntity> GetStudentsByClasses(int classId);
18 
19         /// <summary>
20         /// 通过id查询学生信息
21         /// </summary>
22         /// <param name="id"></param>
23         /// <returns></returns>
24         public StudentEntity GetSudent(int id);
25 
26         /// <summary>
27         /// 新增学生
28         /// </summary>
29         /// <param name="student"></param>
30         /// <returns></returns>
31         public int AddStudent(StudentEntity student);
32 
33         /// <summary>
34         /// 修改学生
35         /// </summary>
36         /// <param name="student"></param>
37         /// <returns></returns>
38         public int UpdateStudent(StudentEntity student);
39 
40         /// <summary>
41         /// 删除学生
42         /// </summary>
43         /// <param name="id"></param>
44         public int DeleteStudent(int id);
45     }
46 }

学生服务实现类StudentAppService

学生服务实现类是对接口的实现，如下所示：

  1 namespace SIMS.WebApi.Services.Student
  2 {
  3     public class StudentAppService : IStudentAppService
  4     {
  5         private DataContext dataContext;
  6 
  7         public StudentAppService(DataContext dataContext) { 
  8             this.dataContext = dataContext;
  9         }
 10 
 11         /// <summary>
 12         /// 新增学生
 13         /// </summary>
 14         /// <param name="student"></param>
 15         /// <returns></returns>
 16         public int AddStudent(StudentEntity student)
 17         {
 18             var entry = dataContext.Students.Add(student);
 19             dataContext.SaveChanges();
 20             return 0;
 21         }
 22 
 23         /// <summary>
 24         /// 删除学生
 25         /// </summary>
 26         /// <param name="id"></param>
 27         public int DeleteStudent(int id)
 28         {
 29             var entity = dataContext.Students.FirstOrDefault(x => x.Id == id);
 30             if (entity != null)
 31             {
 32                 dataContext.Students.Remove(entity);
 33                 dataContext.SaveChanges();
 34             }
 35             return 0;
 36         }
 37 
 38         /// <summary>
 39         /// 查询学生列表
 40         /// </summary>
 41         /// <param name="name"></param>
 42         /// <param name="pageNum">页数</param>
 43         /// <param name="pageSize">每页大小</param>
 44         /// <returns></returns>
 45         public PagedRequest<StudentEntity> GetStudents(string no,string name,int pageNum,int pageSize)
 46         {
 47             IQueryable<StudentEntity> students = null;
 48             if (!string.IsNullOrEmpty(name) && string.IsNullOrEmpty(no))
 49             {
 50                 students = dataContext.Students.Where(r => r.Name.Contains(name) && r.No.Contains(no)).OrderBy(r => r.Id);
 51             }
 52             else if (!string.IsNullOrEmpty(name))
 53             {
 54                 students = dataContext.Students.Where(r => r.Name.Contains(name)).OrderBy(r => r.Id);
 55             }
 56             else if (!string.IsNullOrEmpty(name)) {
 57                 students = dataContext.Students.Where(r => r.No.Contains(no)).OrderBy(r => r.Id);
 58             }
 59             else
 60             {
 61                 students = dataContext.Students.Where(r => true).OrderBy(r => r.Id);
 62             }
 63             int count = students.Count();
 64             List<StudentEntity> items;
 65             if (pageSize > 0)
 66             {
 67                 items = students.Skip((pageNum - 1) * pageSize).Take(pageSize).ToList();
 68             }
 69             else {
 70                 items = students.ToList();
 71             }
 72             return new PagedRequest<StudentEntity>()
 73             {
 74                 count = count,
 75                 items = items
 76             };
 77         }
 78 
 79         /// <summary>
 80         /// 查询某一班级的学生列表
 81         /// </summary>
 82         /// <param name="classId"></param>
 83         /// <returns></returns>
 84         public PagedRequest<StudentEntity> GetStudentsByClasses(int classId)
 85         {
 86             IQueryable<StudentEntity> students = dataContext.Students.Where(r => r.ClassesId==classId).OrderBy(r => r.Id);
 87             int count = students.Count();
 88             var items = students.ToList();
 89             return new PagedRequest<StudentEntity>()
 90             {
 91                 count = count,
 92                 items = items
 93             };
 94         }
 95 
 96         /// <summary>
 97         /// 通过id查询学生信息
 98         /// </summary>
 99         /// <param name="id"></param>
100         /// <returns></returns>
101         public StudentEntity GetSudent(int id)
102         {
103             var entity = dataContext.Students.FirstOrDefault(r => r.Id == id);
104             return entity;
105         }
106 
107         /// <summary>
108         /// 修改学生
109         /// </summary>
110         /// <param name="student"></param>
111         /// <returns></returns>
112         public int UpdateStudent(StudentEntity student)
113         {
114             dataContext.Students.Update(student);
115             dataContext.SaveChanges();
116             return 0;
117         }
118     }
119 }
View Code

班级服务接口IClassesAppService

班级服务接口是对班级表操作的封装，如下所示：

 1 namespace SIMS.WebApi.Services.Classes
 2 {
 3     public interface IClassesAppService
 4     {
 5         public PagedRequest<ClassesEntity> GetClassess(string dept, string grade, int pageNum, int pageSize);
 6 
 7         /// <summary>
 8         /// 通过id查询班级信息
 9         /// </summary>
10         /// <param name="id"></param>
11         /// <returns></returns>
12         public ClassesEntity GetClasses(int id);
13 
14         /// <summary>
15         /// 新增班级
16         /// </summary>
17         /// <param name="classes"></param>
18         /// <returns></returns>
19         public int AddClasses(ClassesEntity classes);
20 
21         /// <summary>
22         /// 修改班级
23         /// </summary>
24         /// <param name="classes"></param>
25         /// <returns></returns>
26         public int UpdateClasses(ClassesEntity classes);
27 
28         /// <summary>
29         /// 删除班级
30         /// </summary>
31         /// <param name="id"></param>
32         public int DeleteClasses(int id);
33     }
34 }

班级服务实现类ClassesAppService，如下所示：

 1 namespace SIMS.WebApi.Services.Classes
 2 {
 3     public class ClassesAppService : IClassesAppService
 4     {
 5         private DataContext dataContext;
 6 
 7         public ClassesAppService(DataContext dataContext)
 8         {
 9             this.dataContext = dataContext;
10         }
11 
12         /// <summary>
13         /// 新增班级
14         /// </summary>
15         /// <param name="classes"></param>
16         /// <returns></returns>
17         public int AddClasses(ClassesEntity classes)
18         {
19             var entry = dataContext.Classes.Add(classes);
20             dataContext.SaveChanges();
21             return 0;
22         }
23 
24         /// <summary>
25         /// 删除班级
26         /// </summary>
27         /// <param name="id"></param>
28         public int DeleteClasses(int id)
29         {
30             var entity = dataContext.Classes.FirstOrDefault(x => x.Id == id);
31             if (entity != null)
32             {
33                 dataContext.Classes.Remove(entity);
34                 dataContext.SaveChanges();
35             }
36             return 0;
37         }
38 
39         /// <summary>
40         /// 查询班级
41         /// </summary>
42         /// <param name="id"></param>
43         /// <returns></returns>
44         public ClassesEntity GetClasses(int id)
45         {
46             var entity = dataContext.Classes.FirstOrDefault(r => r.Id == id);
47             return entity;
48         }
49 
50         public PagedRequest<ClassesEntity> GetClassess(string dept, string grade, int pageNum, int pageSize)
51         {
52             IQueryable<ClassesEntity> classes = null;
53             if (!string.IsNullOrEmpty(dept) && string.IsNullOrEmpty(grade))
54             {
55                 classes = dataContext.Classes.Where(r => r.Dept.Contains(dept) && r.Grade.Contains(grade)).OrderBy(r => r.Id);
56             }
57             else if (!string.IsNullOrEmpty(dept))
58             {
59                 classes = dataContext.Classes.Where(r => r.Dept.Contains(dept)).OrderBy(r => r.Id);
60             }
61             else if (!string.IsNullOrEmpty(grade))
62             {
63                 classes = dataContext.Classes.Where(r => r.Grade.Contains(grade)).OrderBy(r => r.Id);
64             }
65             else
66             {
67                 classes = dataContext.Classes.Where(r => true).OrderBy(r => r.Id);
68             }
69             int count = classes.Count();
70             List<ClassesEntity> items=new List<ClassesEntity>();
71             if (pageSize < 1)
72             {
73                 items = classes.ToList();
74             }
75             else { 
76                items = classes.Skip((pageNum - 1) * pageSize).Take(pageSize).ToList();
77             }
78             
79             return new PagedRequest<ClassesEntity>()
80             {
81                 count = count,
82                 items = items
83             };
84         }
85 
86         /// <summary>
87         /// 修改班级
88         /// </summary>
89         /// <param name="classes"></param>
90         /// <returns></returns>
91         public int UpdateClasses(ClassesEntity classes)
92         {
93             dataContext.Classes.Update(classes);
94             dataContext.SaveChanges();
95             return 0;
96         }
97     }
98 }
View Code

其他服务接口和类尚不完善，暂时先不贴代码。

3. 创建控制器

接口控制器就是客户端访问的入口，与接口服务对应，一个四个接口控制器，如下所示：

学生控制器StudentController

学生控制器封装学生操作的服务，包括学生的增删改查的接口，如下所示：

 1 namespace SIMS.WebApi.Controllers
 2 {
 3     /// <summary>
 4     /// 学生控制器
 5     /// </summary>
 6     [Route("api/[controller]/[action]")]
 7     [ApiController]
 8     public class StudentController : ControllerBase
 9     {
10         private readonly ILogger<StudentController> logger;
11 
12         private readonly IStudentAppService studentAppService;
13 
14         public StudentController(ILogger<StudentController> logger, IStudentAppService studentAppService) {
15             this.logger = logger;
16             this.studentAppService = studentAppService;
17         }
18 
19         /// <summary>
20         /// 学生列表，带分页
21         /// </summary>
22         /// <param name="pageNum"></param>
23         /// <param name="pageSize"></param>
24         /// <param name="no"></param>
25         /// <param name="name"></param>
26         /// <returns></returns>
27         [HttpGet]
28         public PagedRequest<StudentEntity> GetStudents(int pageNum, int pageSize,string? no = null ,string? name=null ) { 
29             return studentAppService.GetStudents(no,name, pageNum, pageSize);
30         }
31 
32         /// <summary>
33         /// 查询某一班级的学生列表
34         /// </summary>
35         /// <param name="classId"></param>
36         /// <returns></returns>
37         [HttpGet]
38         public PagedRequest<StudentEntity> GetStudentsByClasses(int classId) {
39             return studentAppService.GetStudentsByClasses(classId);
40         }
41 
42         /// <summary>
43         /// 获取学生信息
44         /// </summary>
45         /// <param name="id"></param>
46         /// <returns></returns>
47         [HttpGet]
48         public StudentEntity GetStudent(int id) {
49             return studentAppService.GetSudent(id);
50         }
51 
52         /// <summary>
53         /// 新增学生
54         /// </summary>
55         /// <param name="student"></param>
56         /// <returns></returns>
57         [HttpPost]
58         public int AddStudent(StudentEntity student)
59         {
60             return studentAppService.AddStudent(student);
61         }
62 
63         /// <summary>
64         /// 修改学生
65         /// </summary>
66         /// <param name="student"></param>
67         /// <returns></returns>
68         [HttpPut]
69         public int UpdateStudent(StudentEntity student) { 
70             return studentAppService.UpdateStudent(student);
71         }
72 
73         /// <summary>
74         /// 删除学生
75         /// </summary>
76         /// <param name="id"></param>
77         [HttpDelete]
78         public int DeleteStudent(int id)
79         {
80             return studentAppService.DeleteStudent(id);
81         }
82     }
83 }

班级控制器ClassesController

班级控制器是对班级接口服务的封装，包含对班级的增删改查，如下所示：

 1 namespace SIMS.WebApi.Controllers
 2 {
 3     /// <summary>
 4     /// 班级控制器
 5     /// </summary>
 6     [Route("api/[controller]/[action]")]
 7     [ApiController]
 8     public class ClassesController : ControllerBase
 9     {
10         private readonly ILogger<ClassesController> logger;
11 
12         private readonly IClassesAppService classesAppService;
13 
14         public ClassesController(ILogger<ClassesController> logger, IClassesAppService classesAppService)
15         {
16             this.logger = logger;
17             this.classesAppService = classesAppService;
18         }
19 
20         /// <summary>
21         /// 获取班级信息
22         /// </summary>
23         /// <param name="id"></param>
24         /// <returns></returns>
25         [HttpGet]
26         public ClassesEntity GetClasses(int id)
27         {
28             return classesAppService.GetClasses(id);
29         }
30 
31         /// <summary>
32         /// 获取班级列表
33         /// </summary>
34         /// <param name="id"></param>
35         /// <returns></returns>
36         [HttpGet]
37         public PagedRequest<ClassesEntity> GetClassess(string? dept, string? grade, int pageNum, int pageSize)
38         {
39             return classesAppService.GetClassess(dept,grade,pageNum,pageSize);
40         }
41 
42         /// <summary>
43         /// 新增班级
44         /// </summary>
45         /// <param name="classes"></param>
46         /// <returns></returns>
47         [HttpPost]
48         public int AddClasses(ClassesEntity classes)
49         {
50             return classesAppService.AddClasses(classes);
51         }
52 
53         /// <summary>
54         /// 修改班级
55         /// </summary>
56         /// <param name="classes"></param>
57         /// <returns></returns>
58         [HttpPut]
59         public int UpdateClasses(ClassesEntity classes)
60         {
61             return classesAppService.UpdateClasses(classes);
62         }
63 
64         /// <summary>
65         /// 删除班级
66         /// </summary>
67         /// <param name="id"></param>
68         [HttpDelete]
69         public int DeleteClasses(int id)
70         {
71             return classesAppService.DeleteClasses(id);
72         }
73     }
74 }

注意：其他控制器，暂是代码不全，暂不贴示。

通过以上示例可以看出，接口服务依赖DataContext，控制器依赖接口服务，那么如果要使程序得以运行，就要逐层创建对象，并传递对象实体。手工创建非常不方便，所以就需要引入Autofac进行自动注入，如下所示：

4. 注入DataContext

在Program中，通过构造器，注入DataContext，如下所示：

1 builder.Services.AddDbContext<DataContext>(options => options.UseSqlServer(builder.Configuration.GetConnectionString("Default")));

注意：Default为appsetting.json中配置的数据库连接字符串。如下所示：

 1 {
 2   "Logging": {
 3     "LogLevel": {
 4       "Default": "Information",
 5       "Microsoft.AspNetCore": "Warning"
 6     }
 7   },
 8   "ConnectionStrings": {
 9     "Default": "Server=localhost;Database=SIMS;Trusted_Connection=True;User Id=sa;Password=abc123"
10   },
11   "AllowedHosts": "*"
12 }

5. 配置Autofac框架

Autoface框架可以实现接口的自动注入，减少繁琐的人工操作，如下所示：

1 // 以下是autofac依赖注入
2 builder.Host.UseServiceProviderFactory(new AutofacServiceProviderFactory());
3 builder.Host.ConfigureContainer<ContainerBuilder>(builder =>
4 {   // 注入Service程序集
5     string assemblyName = Assembly.GetExecutingAssembly().GetName().Name;
6     builder.RegisterAssemblyTypes(Assembly.Load(assemblyName))
7     .AsImplementedInterfaces()
8     .InstancePerDependency();
9 });

Program中全部代码，如下所示：

 1 using Autofac;
 2 using Autofac.Extensions.DependencyInjection;
 3 using Microsoft.EntityFrameworkCore;
 4 using SIMS.WebApi;
 5 using SIMS.WebApi.Data;
 6 using SIMS.WebApi.Services.Student;
 7 using System.Configuration;
 8 using System.Reflection;
 9 
10 var builder = WebApplication.CreateBuilder(args);
11 
12 // Add services to the container.
13 
14 builder.Services.AddControllers();
15 // Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
16 builder.Services.AddEndpointsApiExplorer();
17 builder.Services.AddSwaggerGen();
18 builder.Services.AddDbContext<DataContext>(options => options.UseSqlServer(builder.Configuration.GetConnectionString("Default")));
19 // 以下是autofac依赖注入
20 builder.Host.UseServiceProviderFactory(new AutofacServiceProviderFactory());
21 builder.Host.ConfigureContainer<ContainerBuilder>(builder =>
22 {   // 注入Service程序集
23     string assemblyName = Assembly.GetExecutingAssembly().GetName().Name;
24     builder.RegisterAssemblyTypes(Assembly.Load(assemblyName))
25     .AsImplementedInterfaces()
26     .InstancePerDependency();
27 });
28 var app = builder.Build();
29 
30 // Configure the HTTP request pipeline.
31 if (app.Environment.IsDevelopment())
32 {
33     app.UseSwagger();
34     app.UseSwaggerUI();
35 }
36 
37 app.UseHttpsRedirection();
38 
39 app.UseAuthorization();
40 
41 app.MapControllers();
42 
43 app.Run();
View Code

 

6. 代码结构

 

WebApi中代码结构如下所示：

 

 

7. 运行WebApi服务

经过以上步骤的操作，Api接口已经基本搭建完成，将SIMS.WebApi作为启动项目，运行VS，如下所示：

 

8. 接口测试

默认情况下WebApi继承了Swagger，可以进行简单的测试，以/api/Classes/GetClasses为例，输入班级ID，就可查询班级信息，如下所示：

 

 以上就是本次的主要内容，包含数据库的基本操作和WebApi接口的创建流程，旨在抛转引玉，一起学习，共同进步。

备注

上邪【作者】佚名 【朝代】汉

上邪，我欲与君相知，长命无绝衰。

山无陵，江水为竭。

冬雷震震，夏雨雪。

天地合，乃敢与君绝。

posted @ 2022-05-25 22:57  老码识途呀  阅读(2537)  评论(0)  编辑  收藏  举报