ASP.NET Core - 依赖注入 - IdentityServer4 DbContext

Question

我一直在努力寻找最好/首选的方法是让我的RoleService 获得ConfigurationDbContext (IdentityServer4)。

我真的很想解耦，以便我的 RoleService 可以测试。

我发现访问ConfigurationDbContext 的唯一方法是在Startup.cs 中创建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:

中使用此代码

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 中获得依赖的最佳方式吗？

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得context？

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来将依赖项传递给RoleService。

根据您的RoleService 的生命周期（根据提供的代码无法判断），如果服务已经是Scoped，您可以将ConfigurationDbContext 直接传递给RoleService。或者您可以通过 IServiceScopeFactory 在您的服务中手动创建一个范围。

类似：

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），您最终可能会创建一个内存中的 ConfigurationDbContext。 您使用的 IdentityServer4.EntityFramework 存储库有一些用于测试 here 的示例。