ASP.NETCore使用AutoFac依赖注入

实现代码

1、新建接口类：IRepository.cs，规范各个操作类的都有那些方法，方便管理。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;

namespace CMS.Entity.Interfaces
{
    public  interface IRepository<T> where T:class
    {
        /// <summary>
        /// 添加
        /// </summary>
        /// <param name="entity">实体对象</param>
        void Add(T entity);
        /// <summary>
        /// 更新
        /// </summary>
        /// <param name="entity">实体对象</param>
        void Update(T entity);
        /// <summary>
        /// 删除
        /// </summary>
        /// <param name="entity">实体对象</param>
        void Delete(T entity);
        /// <summary>
        /// 删除
        /// </summary>
        /// <param name="where">条件(lambda表达式)</param>
        void Delete(Expression<Func<T, bool>> where);
        /// <summary>
        /// 根据ID获取一个对象
        /// </summary>
        /// <param name="Id">主键ID</param>
        /// <returns>对象</returns>
        T GetById(long Id);
        /// <summary>
        /// 根据ID获取一个对象
        /// </summary>
        /// <param name="Id">主键ID</param>
        /// <returns>对象</returns>
        T GetById(string Id);
        /// <summary>
        /// 根据条件获取一个对象
        /// </summary>
        /// <param name="where">条件(lambda表达式)</param>
        /// <returns>对象</returns>
        T Get(Expression<Func<T, bool>> where);
        /// <summary>
        /// 获取所有数据
        /// </summary>
        /// <returns>所有数据</returns>
        IQueryable<T> GetAll();
        /// <summary>
        /// 根据条件获取数据
        /// </summary>
        /// <param name="where">条件(lambda表达式)</param>
        /// <returns>数据</returns>
        IQueryable<T> GetMany(Expression<Func<T, bool>> where);
        /// <summary>
        /// 根据条件获取记录数
        /// </summary>
        /// <param name="where">条件(lambda表达式)</param>
        /// <returns></returns>
        int GetCount(Expression<Func<T, bool>> where);
        /// <summary>
        /// 关闭代理
        /// </summary>
        void CloseProxy();
        /// <summary>
        /// 打开代理
        /// </summary>
        void OpenProxy();
        /// <summary>
        /// 是否有指定条件的元素
        /// </summary>
        /// <param name="where">条件(lambda表达式)</param>
        /// <returns></returns>
        bool IsHasValue(Expression<Func<T, bool>> where);
    }
}

2、新建仓储基础操作类RepositoryBase.cs，注意要一一对应实现IRepositroy接口的方法

using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;

namespace CMS.Entity.Interfaces
{
    public abstract class BaseRepository<T>  where T: class
    {
        private BcmfDBContext db;//数据库上下文

        public BaseRepository(BcmfDBContext _db) {
            db = _db;
        }

        public virtual void Save()
        {
            db.SaveChanges();
        }

        public  virtual  void Add(T entity)
        {
            db.Set<T>().Add(entity);
        }

        public virtual void CloseProxy()
        {
            db.Database.CommitTransaction();
        }

        public virtual void Delete(T entity)
        {
            db.Set<T>().Remove(entity);
        }

        public virtual void Delete(System.Linq.Expressions.Expression<Func<T, bool>> where)
        {
            var dataList = db.Set<T>().Where(where).AsEnumerable();
            db.Set<T>().RemoveRange(dataList);
        }

        public virtual T Get(System.Linq.Expressions.Expression<Func<T, bool>> where)
        {
           return db.Set<T>().FirstOrDefault(where);
        }

        public virtual System.Linq.IQueryable<T> GetAll()
        {
            return db.Set<T>();
        }

        public virtual T GetById(long Id)
        {
            return db.Set<T>().Find(Id);
        }

        public virtual T GetById(string Id)
        {
            return db.Set<T>().Find(Id);
        }

        public virtual int GetCount(System.Linq.Expressions.Expression<Func<T, bool>> where)
        {
            return db.Set<T>().Count(where);
        }

        public virtual System.Linq.IQueryable<T> GetMany(System.Linq.Expressions.Expression<Func<T, bool>> where)
        {
            return db.Set<T>().Where(where);
        }

        public virtual bool IsHasValue(System.Linq.Expressions.Expression<Func<T, bool>> where)
        {
            return db.Set<T>().Any(where);
        }

        public virtual void OpenProxy()
        {
            db.Database.BeginTransaction();
        }

        public virtual void Update(T entity)
        {
            db.Set<T>().Attach(entity);
            db.Entry<T>(entity).State = Microsoft.EntityFrameworkCore.EntityState.Modified;
        }
    }
}

3、新建仓储类TUserRepository与TOperateLogRepository，TUserRepository用于操作用户表，TOperateLogRepository用于操作用户记录表，对应的User类与OperateLog类根据项目需求自行创建

using System;
using System.Collections.Generic;
using System.Text;
using CMS.Entity.Repository;
using CMS.Entity.Entity;
using Microsoft.EntityFrameworkCore;
using System.Linq;
using CMS.Entity.Interfaces;

namespace CMS.Entity.Repository
{
    public class TUserRepository :BaseRepository<User>,IUserRepository
    {
        public TUserRepository(BcmfDBContext db) : base(db) { }
    }
    public interface IUserRepository : IRepository<User> { }
}

using System;
using System.Collections.Generic;
using System.Text;
using CMS.Entity.Repository;
using CMS.Entity.Entity;
using Microsoft.EntityFrameworkCore;
using System.Linq;
using CMS.Entity.Interfaces;

namespace CMS.Entity.Repository
{

    public class TOperateLogRepository : BaseRepository<OperateLog>, IOperateLogRepository
    {
        public TOperateLogRepository(BcmfDBContext db) : base(db) { }
    }
    public interface IOperateLogRepository : IRepository<OperateLog>
    {
    }
}

4、分别在UserController与OperateLogController控制器中的构造函数注入仓储类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using CMS.Entity;
using CMS.Entity.Entity;
using Newtonsoft.Json;
using CMS.WebApi.Core;
using Microsoft.EntityFrameworkCore.Query;
using CMS.Entity.Repository;

namespace CMS.WebApi.Controllers
{
    /// <summary>
    /// 用户中心
    /// </summary>
    //[Produces("application/json")]
    [Route("api/[controller]")]
    [ApiController]
    public class UsersController : ControllerBase
    {

        private readonly IUserRepository userRepository;
        public UsersController(IUserRepository _userRepository)
        {
            userRepository = _userRepository;
        }

        /// <summary>
        /// 获取用户列表
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        public string Get()
        {
            var userList= userRepository.GetAll().ToList();
            return JsonConvert.SerializeObject(userList);
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using CMS.Entity.Repository;
using Newtonsoft.Json;

namespace CMS.WebApi.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class OperateLogController : ControllerBase
    {
        private readonly IOperateLogRepository operateLogRepository;
        public OperateLogController(IOperateLogRepository _operateLogRepository)
        {
            operateLogRepository = _operateLogRepository;
        }

        [HttpGet]
        public string Get()
        {
            var result = operateLogRepository.GetMany(m=>m.ActionLogId<100);
            return JsonConvert.SerializeObject(result);
        }
    }
}

5、完成上述操作后，运行获取数据时会系统报错，那是由于还没将仓储类注入到服务中，接下来就实现用AutoFac注入仓储类到项目服务中

添加引用Autofac，Auto.Configuration，Autofac.Extensions.DependencyInjection到项目中

这里贴出Nuget程序控制台命令：

Install-Package Autofac -Version 4.9.2

Install-Package Autofac.Configuration -Version 4.1.0

Install-Package Autofac.Extensions.DependencyInjection -Version 4.4.0

6、打开项目Startup.cs，找到ConfigureServices方法，将void改为IServiceProvider返回值，如下

 //先引用命名空间using Autofac;using Autofac.Extensions.DependencyInjection;

public IServiceProvider ConfigureServices(IServiceCollection services)
        {
            ...

            ////批量匹配注入，使用AutoFac提供的容器接管当前项目默认容器
            var builder = new ContainerBuilder();
            //注入entity层的repository类builder.RegisterType(typeof(TUserRepository)).As(typeof(IUserRepository)).InstancePerDependency();
            //批量注入Repository的类
       　　builder.RegisterAssemblyTypes(typeof(TUserRepository).Assembly)
                .Where(t => t.Name.EndsWith("Repository"))
                .AsImplementedInterfaces();
            builder.Populate(services);
            var container = builder.Build();
            //ConfigureServices方法由void改为返回IServiceProvider
            return new AutofacServiceProvider(container);
        }

7、重新生成发布项目，完成

原文地址：https://www.cnblogs.com/luckypc/p/11002805.html