按照DDD的方式写的一个.net有关Web项目框架

理想很丰满，现实往往很残酷。

一种按照ddd的方式，根据业务来把自己需要的模块一个一个写出来，再按照模块把需要的接口一个一个的写出来，堆砌一些中间件，以及解耦的command，handler等等

，一个项目就这么成型了。上面的项目有一个非常清晰的特点，就是按需开发，不需要去可以定义业务相关的公共的模块，有就有没就没。这项目看起来没有什么公共框架，就是一个项目。当然这样效率性能也是最高的，不需要过多的包装一层又一层的公共代码。

有关示例如下，不做过多的赘述：

liuzhixin405/netcore-micro (github.com)

一种业务非常大，开发人员只需要写业务实现，这就需要一个公共框架，提供公共的可复制模块让业务人员写业务代码。

下面以为简洁的方式呈现这种开发模式，项目层级如下：

三个模块分别是业务模块，主机，基础模块。业务模块Business通过dll形式提供给host来完成注册和发布。

主机host可以存放公共的基础模块，例如注册、登录、认证等，这里省略。

业务模块存放业务代码，包括提供接口。

流程如下：request => 业务模块controller => business => service=> repository

整个项目接口不变，实现可各异。

在仓储层定义几个公共的方法，

 public interface IRepository<TEntity,TID> where TEntity : IEntity<TID>{Task<ApiResult> AddAsync(TEntity entity);Task<ApiResult> UpdateAsync(TEntity entity);Task<ApiResult> DeleteAsync(Expression<Func<TEntity, bool>> filter);Task<ApiResult> DeleteAsync(TID id);// 通用分页查询Task<PagedResult<TEntity>> GetPagedAsync(PagingParameters<TEntity> pagingParameters);// 其他常用操作Task<IEnumerable<TEntity>> FindAsync(Expression<Func<TEntity, bool>> filter);}

服务层也是同样的方法

 [Intercept("business-service log")]public interface IService{Task<ApiResult> AddAsync(IRequestDto requestDto);Task<ApiResult> UpdateAsync(IRequestDto requestDto);Task<ApiResult> DeleteAsyncc(IRequestDto requestDto);Task<ApiResult> GetPagedAsyncc(IRequestDto requestDto) ;Task<ApiResult> FindAsyncc(IRequestDto requestDto);}

依赖注入还是老一套，实现它就行。

 public interface IModule{void ConfigureService(IServiceCollection services, IConfiguration configuration = null);void Configure(IApplicationBuilder app, IWebHostEnvironment env = null);}public abstract class ModuleBase : IModule{public virtual void ConfigureService(IServiceCollection services, IConfiguration configuration = null){}public virtual void Configure(IApplicationBuilder app, IWebHostEnvironment env = null){}}

在主机通过扫描assembly来注册服务

using Microsoft.AspNetCore.Mvc.ApplicationParts;
using Project.Base.Reflect;
using System.Reflection;
using Project.Base.ProjExtension;
using Project.Base.Common;
using Project.Base.DependencyInjection;
using Project.Base.Module;
namespace Project.Host
{public class Program{public static void Main(string[] args){var builder = WebApplication.CreateBuilder(args);builder.Configuration.AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);builder.Configuration.AddJsonFile($"appsettings.{builder.Environment.EnvironmentName}.json", optional: true, reloadOnChange: true);builder.Configuration.AddJsonFile("appsettings.Modules.json", optional: false, reloadOnChange: true);//IModule注入 ,然后扫描调用ConfigureService，Business注入需要的服务入口
            builder.Services.InitModule(builder.Configuration);var sp = builder.Services.BuildServiceProvider();var moduleInitializers = sp.GetServices<IModule>();foreach (var moduleInitializer in moduleInitializers){moduleInitializer.ConfigureService(builder.Services, builder.Configuration);}// Add services to the container.var assemblys = GolbalConfiguration.Modules.Select(x => x.Assembly).ToList();var mvcBuilder=builder.Services.AddControllers().ConfigureApplicationPartManager(apm => {var folder = Path.Combine(Directory.GetCurrentDirectory(), "bus_lib");var serviceList = (builder.Configuration.GetSection("ServiceList").Get<string[]>()) ?? new string[] { "ADM" };//默认加载基础服务string[] serviceFiles = Directory.GetFiles(folder, "*.Api.dll").Where(x =>serviceList.Any(y => x.Contains(y))).ToArray();foreach (var file in serviceFiles){if (File.Exists(file)){var assembly = Assembly.LoadFrom(file);var controllerAssemblyPart = new AssemblyPart(assembly);apm.ApplicationParts.Add(controllerAssemblyPart);}}});foreach (var assembly in assemblys){// 扫描并注册其他程序集中的控制器
                mvcBuilder.AddApplicationPart(assembly);// 扫描并注册其他程序集中的服务   针对特性注入
                builder.Services.ReisterServiceFromAssembly(assembly);} // Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
            builder.Services.AddEndpointsApiExplorer();builder.Services.AddSwaggerGen();builder.Services.AddBusinessServices();var app = builder.Build();ServiceLocator.Instance = app.Services;//imodule 的Configure调用,business可以实现中间件等操作foreach (var moduleInitializer in moduleInitializers){moduleInitializer.Configure(app, app.Environment);}// Configure the HTTP request pipeline.if (app.Environment.IsDevelopment()){app.UseSwagger();app.UseSwaggerUI();}app.UseHttpsRedirection();app.UseAuthorization();app.MapControllers();app.Run();}}
}

业务需求注入代码如下：

using ADM001_User.Model;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using MongoDB.Bson.Serialization.Serializers;
using MongoDB.Bson.Serialization;
using MongoDB.Bson;
using MongoDB.Driver;
using Project.Base.IRepository;
using Project.Base.Module;
using Project.Base.Reflect;
using Project.Base.Repository;
using Project.Base.Services;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using ADM001_User.Business.Settings;
using Project.Base.Model;namespace ADM001_User.Business
{public class UserModule : ModuleBase{public override void ConfigureService(IServiceCollection services, IConfiguration configuration = null){services.AddDbContext<UserDbContext>(options =>options.UseInMemoryDatabase("InMemoryDb"));services.AddScoped<IRepository<User, int>, GenericRepository<User, int, UserDbContext>>();services.AddTransient<IService, UserService>();AddMongo(services);AddMongoRepository<User, int>(services, "users");}private static IServiceCollection AddMongo(IServiceCollection services){BsonSerializer.RegisterSerializer(new GuidSerializer(BsonType.String));BsonSerializer.RegisterSerializer(new DateTimeOffsetSerializer(BsonType.String));services.AddSingleton(serviceProvider =>{var configuration = serviceProvider.GetService<IConfiguration>();var serviceSettings = configuration.GetSection(nameof(ServiceSettings)).Get<ServiceSettings>();var mongoDbSettings = configuration.GetSection(nameof(MongoDbSettings)).Get<MongoDbSettings>();var mongoClient = new MongoClient(mongoDbSettings.ConenctionString);return mongoClient.GetDatabase(serviceSettings.ServiceName);});return services;}private static IServiceCollection AddMongoRepository<T, TID>(IServiceCollection services, string collectionName) where T : IEntity<TID>{services.AddSingleton<IRepository<User, int>>(serviceProvider =>{var db = serviceProvider.GetService<IMongoDatabase>();return new MongoRepository<User, int>(db, "collectionname");});return services;}}
}

在business层加了aop,通过proxy的方式

using Castle.DynamicProxy;
using Microsoft.Extensions.DependencyInjection;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;namespace Project.Base.Reflect
{public static class ServiceExtension{private static readonly ProxyGenerator _generator = new ProxyGenerator();public static IServiceCollection AddBusinessServices(this IServiceCollection services){var folder = Path.Combine(Directory.GetCurrentDirectory(), "bus_lib");var dllFiles = Directory.GetFiles(folder, "*.Business.dll");var assemblies = dllFiles.Select(Assembly.LoadFrom).ToArray();var businessTypes = assemblies.SelectMany(a => a.GetTypes().Where(t => t.IsClass&&!t.IsAbstract)).Where(type => type.GetInterfaces().Any(i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IBusiness<>))).ToList();CastleInterceptor castleInterceptor = new CastleInterceptor();foreach (var type in businessTypes){var interfaceType = type.GetInterfaces().First(i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IBusiness<>));services.AddTransient(interfaceType, provider =>{var target = ActivatorUtilities.CreateInstance(provider, type);return _generator.CreateInterfaceProxyWithTarget(interfaceType, target, castleInterceptor);});}return services;}}
}

在你需要的每个方法前加上特性就可以了

using Project.Base.Model;
using Project.Base.ProjAttribute;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;namespace ADM001_User.Business
{/// <summary>/// 有需要就实现前后动作/// </summary>public class AddAop: BaseAopAttribute{public override Task After(BusinessAopContext aopContext){return Task.CompletedTask;}public override Task Before(BusinessAopContext aopContext){return Task.CompletedTask;}}
}

再控制器层加了个公共的，不管是controller拦截还是公共的部分都可以写到这里

 [Route("api/[controller]/[action]")][ApiController]public class InitController<TModel>:ControllerBase{protected readonly ILogger<InitController<TModel>> _logger;public InitController(ILogger<InitController<TModel>> logger){_logger = logger;}}