使用 .NET Core 2.1、NPGSQL、實體框架和 Linux。從 Startups.cs 的 Configure 函數中，我在依賴注入類中調用一個函數，該類又調用另一個依賴注入類，該類使用 Entity Framework + NPGSQL 訪問數據庫。配置服務：    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();        }    }音樂管理器實現看起來像這樣：    private readonly IMusicRepo _musicStoreRepo;    public MusicManager(IMusicRepo musicStoreRep)    {        _musicStoreRepo = musicStoreRepo;    }    public void DoSomeDBStartupStuff()    {        _musicStoreRepo.InsertSampleStuff();        _musicStoreRepo.CheckThisAndCheckThat();    }音樂庫實現看起來像這樣：    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上下文這是這樣實現的：public class MMContext : DbContext{    public MMContext(DbContextOptions<MMContext> options) : base(options) {}    ... OnModelCreating etc...}