class Program
    {
        static void Main(string[] args)
        {
            var config = new ConfigurationBuilder()
                 .AddJsonFile("appsettings.json")
                 .Build();
            var services = new ServiceCollection()
                .AddSingleton<IConfiguration>(config)
                .AddOptions()
                .AddSingleton<IConfigureOptions<FxOptions>, FxOptionsSetup>()
                .AddScoped<IDbProvider, DbProvider>()
                .AddSingleton<IUnitOfWorkFactory, UnitOfWorkFactory>()
                .AddSingleton<IRepositoryFactory, RepositoryFactory>()
                .AddSingleton<IDbContextOptionsBuilderUser, SqlServerDbContextOptionsBuilderUser>()
                .AddSingleton<DbContextOptionsBuilderOptions>(new DbContextOptionsBuilderOptions(new DbContextOptionsBuilder<TestDbContext>(), null, typeof(TestDbContext)));

            var serviceProvider = services.BuildServiceProvider();

            var dbProvider = serviceProvider.GetRequiredService<IDbProvider>();
            var uow = dbProvider.GetUnitOfWork<TestDbContext>("TestDb"); // 访问主库

            var repoDbTest = uow.GetRepository<DbTest, int>();
            var obj = new DbTest { Name = "123", Date = DateTime.Now.Date };
            repoDbTest.Insert(obj);
            uow.SaveChanges();
            
            Console.ReadKey();
            
            var uow2 = dbProvider.GetUnitOfWork<TestDbContext>("TestDb_Read");

             var uow2 = dbProvider.GetUnitOfWork<TestDbContext>("TestDb_Read"); // 访问从库
            var repoDbTest2 = uow2.GetReadOnlyRepository<DbTest, int>();
            var data2 = repoDbTest2.GetFirstOrDefault();
            Console.WriteLine($"id: {data2.Id} name: {data2.Name}");
            Console.ReadKey();
        }
    }

这里直接用控制台来做一个例子,中间多了一个Console.ReadKey()是因为我本地没有配置主从模式,所以实际上我是先插入数据,然后复制到另一个数据库里,再进行读取的.

总结

本文给出的解决方案适用于系统中存在多个不同的上下文,能够适应复杂的业务场景.但对已有代码的侵入性比较大,不知道有没有更好的方案,欢迎一起探讨.