c# - ASP.NET Core - 依赖注入(inject) - IdentityServer4 DbContext

Question

我一直在努力寻找让我的 RoleService 获得 ConfigurationDbContext (IdentityServer4) 的最佳/首选方法。

我真的很想解耦，这样我的 RoleService 就可以测试了。

我发现访问 ConfigurationDbContext 的唯一方法是在 Startup.cs 中创建一个 public static IServiceProvider:

public class Startup
{
    private readonly IHostingEnvironment _environment;

    // THIS IS THE PROPERTY I USED
    public static IServiceProvider ServiceProvider { get; private set; }

    public ConfigurationDbContext GetConfigurationDbContext()
    {
        return null;
    }

    public Startup(ILoggerFactory loggerFactory, IHostingEnvironment environment)
    {
        loggerFactory.AddConsole(LogLevel.Debug);
        _environment = environment;
    }

    public void ConfigureServices(IServiceCollection services)
    {
        var connectionString = DbSettings.IdentityServerConnectionString;
        var migrationsAssembly = typeof(Startup).GetTypeInfo().Assembly.GetName().Name;

        // configure identity server with in-memory stores, keys, clients and scopes
        var identityServerConfig = services.AddIdentityServer()
            .AddConfigurationStore(builder =>
                builder.UseSqlServer(connectionString, options =>
                    options.MigrationsAssembly(migrationsAssembly)))
            .AddOperationalStore(builder =>
                builder.UseSqlServer(connectionString, options =>
                    options.MigrationsAssembly(migrationsAssembly)))
            .AddSigningCredential(new X509Certificate2(Path.Combine(_environment.ContentRootPath, "certs", "IdentityServer4Auth.pfx"), "test"));

        identityServerConfig.Services.AddTransient<IResourceOwnerPasswordValidator, ActiveDirectoryPasswordValidator>();
        identityServerConfig.Services.AddTransient<IProfileService, CustomProfileService>();
        services.AddDbContext<ConfigurationDbContext>(options => options.UseSqlServer(connectionString));
        services.AddMvc();
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
    {
        ServiceProvider = app.ApplicationServices;
        // other code emitted
    }
}

然后在 RoleService.cs 中使用这段代码:

public class RoleService : IRoleService
{
    public async Task<ApiResource[]> GetApiResourcesByIds(int[] ids)
    {
        ApiResource[] result;

        using (var serviceScope = Startup.ServiceProvider.GetService<IServiceScopeFactory>().CreateScope())
        {
            var context = serviceScope.ServiceProvider.GetRequiredService<ConfigurationDbContext>();
            result =
                context.ApiResources.Where(x => ids.Contains(x.Id))
                .Include(x => x.Scopes)
                .Include(x => x.UserClaims)
                .ToArray();

            return result;
        }
    }
}

这是在 RoleService.cs 中获取依赖项的最佳方式吗？

有没有办法抽象serviceScope(因为它在using语句中，可能是IDisposable，我真的不知道是否有办法抽象获取上下文?

还有其他建议或最佳做法吗？

Answer 1

您可以通过创建一个将所需依赖项作为构造函数参数的构造函数，将依赖项传递给 RoleService。

根据您的 RoleService 的生命周期(无法根据提供的代码判断)，您可以将 ConfigurationDbContext 直接传递给 RoleService 如果服务已经是 Scoped。或者您将传递 IServiceScopeFactory 以在您的服务中手动创建范围。

类似于:

private readonly IServiceScopeFactory _scopeFactory;

public RoleService(IServiceScopeFactory scopeFactory)
{
    _scopeFactory = scopeFactory;
}

public async Task<ApiResource[]> GetApiResourcesByIds(int[] ids)
{
    using (var scope = _scopeFactory.CreateScope())
    {
        var context = scope.ServiceProvider.GetRequiredService<ConfigurationDbContext>();
    }
}

由于您的方法与 DbContext 紧密耦合(这不一定是坏事)，您可能最终会创建内存中的 ConfigurationDbContext。您使用的 IdentityServer4.EntityFramework 存储库有一些用于测试的示例 here .