使用 .NET Core 2.1、NPGSQL、實(shí)體框架和 Linux。從 Startups.cs 的 Configure 函數(shù)中，我在依賴注入類中調(diào)用一個(gè)函數(shù)，該類又調(diào)用另一個(gè)依賴注入類，該類使用 Entity Framework + NPGSQL 訪問(wèn)數(shù)據(jù)庫(kù)。配置服務(wù)：    public void ConfigureServices(IServiceCollection services)    {        services.AddEntityFrameworkNpgsql()        .AddDbContext<MMContext>(options => options.UseNpgsql($"Host='localhost'; Port=1234;Database='mydb';Username='test';Password='test'"))        .BuildServiceProvider();        services.AddTransient<IMusicManager, MusicManager>();        services.AddTransient<IMusicRepo, MusicRepo>();      services.AddMvc()        .SetCompatibilityVersion(CompatibilityVersion.Version_2_1);    }配置功能：    public void Configure(IApplicationBuilder app, IHostingEnvironment env)    {        app.UseMvc();        using (var scope = app.ApplicationServices.GetService<IServiceScopeFactory>().CreateScope())        {            var mm = scope.ServiceProvider.GetRequiredService<IMusicManager>();            mm.DoSomeDBStartupStuff();        }    }音樂(lè)管理器實(shí)現(xiàn)看起來(lái)像這樣：    private readonly IMusicRepo _musicStoreRepo;    public MusicManager(IMusicRepo musicStoreRep)    {        _musicStoreRepo = musicStoreRepo;    }    public void DoSomeDBStartupStuff()    {        _musicStoreRepo.InsertSampleStuff();        _musicStoreRepo.CheckThisAndCheckThat();    }音樂(lè)庫(kù)實(shí)現(xiàn)看起來(lái)像這樣：    private readonly MMContext _context;    public MusicRepo(MMContext context)    {        _context = context;    }    public void InsertSampleStuff()    {        _context.Music.AddAsync(new music("abc"));        _context.Music.AddAsync(new music("123"));        _context.SaveChangesAsync();    }MM上下文這是這樣實(shí)現(xiàn)的：public class MMContext : DbContext{    public MMContext(DbContextOptions<MMContext> options) : base(options) {}    ... OnModelCreating etc...}