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我有一堂课

 public interface IDbContext : IDisposable
{
    IDbConnection Connection { get; }

    IDbTransaction CreateOpenedTransaction();

    IEnumerable<T> ExecuteProcedure<T>(string procedure, dynamic param = null, IDbTransaction transaction = null);

    int ExecuteProcedure(string procedure, dynamic param = null, IDbTransaction transaction = null);
}

这是实现：

 public sealed class DbContext : IDbContext
{
    private bool disposed;
    private SqlConnection connection;

    public DbContext(string connectionString)
    {
        connection = new SqlConnection(connectionString);
    }

    public IDbConnection Connection
    {
        get
        {
            if (disposed) throw new ObjectDisposedException(GetType().Name);

            return connection;
        }
    }

    public IDbTransaction CreateOpenedTransaction()
    {
        if (connection.State != ConnectionState.Open)
            Connection.Open();
        return Connection.BeginTransaction();
    }

我尝试像这样使用 autofac 解决依赖关系：

公共类 RepositoryBaseTest { 私有静态 IContainer _container;

    [TestInitialize]
    public virtual void TestInitialize()
    {
        var builder = new ContainerBuilder();

        builder.RegisterAssemblyTypes(typeof(ICommandHandler<object>).Assembly)
               .AsImplementedInterfaces()
               .SingleInstance();

        builder.RegisterAssemblyTypes(typeof(IQuery<object>).Assembly)
              .AsImplementedInterfaces()
              .SingleInstance();

        builder.RegisterAssemblyTypes(typeof(IQueryMultiple<object>).Assembly)
              .AsImplementedInterfaces()
              .SingleInstance();

        builder.Register<IMemberRepository>(c =>
        new MemberRepository(
            c.Resolve<IDbContext>()))
        .SingleInstance();

        builder.Register<IDbContext>(c =>
          new DbContext(ConfigurationManager.ConnectionStrings["Speed"].ConnectionString))
          .Named<IDbContext>("Speed")
          .InstancePerDependency();

      _container = builder.Build();
        DependencyResolver.SetResolver(new AutofacDependencyResolver(_container));
    }

    #region Resolve

    protected void ExecuteCommand<T>(T command)
    {
        _container.Resolve<ICommandHandler<T>>().Execute(command);
    }

    protected IEnumerable<T> Query<T>(Func<T, bool> condition)
    {
        return _container.Resolve<IQueryMultiple<T>>().Where(condition);
    }

    protected T Select<T>(Func<T, bool> condition)
    {
        return _container.Resolve<IQuery<T>>().Select(condition);
    }

    protected T Resolve<T>()
    {
        return _container.Resolve<T>();
    }

    #endregion
}

在课堂测试中，我尝试测试：

   public class MemberRepositoryTest : RepositoryBaseTest
{
    private IMemberRepository _memberRepository;

    [TestInitialize]
    public override void TestInitialize()
    {
        base.TestInitialize();
        _memberRepository = new MemberRepository(Resolve<IDbContext>());
    }

但我在这条指令中发现了一个错误：_memberRepository = new MemberRepository(Resolve());

请求的服务“IDbContext”尚未注册。要避免此异常，请注册一个组件以提供服务，使用 IsRegistered() 检查服务注册，或使用 ResolveOptional() 方法解决可选依赖项。

我该如何解决这个问题？

4

1 回答 1

0

解决方案 1. 您已将 IDbContext 注册为命名服务。

.Named<IDbContext>("Speed")

因此，您必须使用 ResolveNamed 方法。

_container.ResolveNamed<IDbContext>("Speed");

解决方案 2. 您可以将 IDbContext 注册为类型。在这种情况下，方法 Resolve() 应该可以正常工作。

builder.Register<IDbContext>(c =>
          new DbContext(ConfigurationManager.ConnectionStrings["Speed"].ConnectionString))
          .InstancePerDependency();
于 2013-07-02T17:33:34.510 回答