在使用Activator.CreateInstance后转换为正确的类型

在使用Activator.CreateInstance(…)后，我遇到了正确类型的问题，这只是返回一个对象类型。所以我的代码如下。我有一个空接口来将对象定义为命令..

/// <summary>
/// Defines the expected members for a Command object
/// </summary>
public interface ICommand { }

我有一个实现这个接口的命令

/// <summary>
/// Contains command data for adding a company
/// </summary>
public class CompanyAddCommand : ICommand
{
    #region Properties
    public bool IsActive { get; protected set; }
    public string CompanyName { get; protected set; }
    public DateTime RecordCreatedDateTime { get; protected set; }
    #endregion
    #region Constructors
    /// <summary>
    /// Initializes a new instance of the <see cref="CompanyAddCommand"/> class.
    /// </summary>
    /// <param name="isActive">if set to <c>true</c> [is active].</param>
    /// <param name="companyName">Name of the company.</param>
    /// <param name="recordCreatedDateTime">The record created date time.</param>
    public CompanyAddCommand(bool isActive,
        string companyName, DateTime recordCreatedDateTime)
    {
        IsActive = isActive;
        CompanyName = companyName;
        RecordCreatedDateTime = recordCreatedDateTime;
    }
    #endregion
}

我有一个命令验证器接口，它有一个方法Validate()和一个类型参数，该类型参数是一个对象，必须是一个类并实现ICommand接口。

public interface IValidationHandler<in TCommand> 
    where TCommand : class, ICommand
{
    /// <summary>
    /// Validates the specified command.
    /// </summary>
    /// <param name="command">The command.</param>
    void Validate(TCommand command);
}

我有一个命令验证器类，实现了IValidationHandler

public class CompanyAddValidator : ValidatorBase, IValidationHandler<CompanyAddCommand>
{
    #region Constructors
    /// <summary>
    /// Initializes a new instance of the <see cref="CompanyAddValidator"/> class.
    /// </summary>
    public CompanyAddValidator(IUnitOfWork unitOfWork)
        : base(unitOfWork)
    { }
    #endregion
    #region IValidationHandler<CompanyAddCommand> Members
    /// <summary>
    /// Validates the specified command.
    /// </summary>
    /// <param name="command">The command.</param>
    public void Validate(
        CompanyAddCommand command)
    {
        ValidateCompanyEntity(command);
        ValidationUniqueCompanyName(command);
    }
    #endregion
    /// <summary>
    /// Validates the company entity.
    /// </summary>
    /// <param name="command">The command.</param>
    private void ValidateCompanyEntity(CompanyAddCommand command)
    {
        // do some work            
    }
    /// <summary>
    /// Validations the name of the unique company.
    /// </summary>
    /// <param name="command">The command.</param>
    private void ValidationUniqueCompanyName(CompanyAddCommand command)
    {
        // do some work;
    }
}

我有一个命令总线，在构造时扫描程序集中所有处理程序类型的类，并将这些类型注册为命令处理程序或验证处理程序中的两个字典之一，其中键是命令类型，值是处理程序类型。

public class CommandBus : ICommandBus
{
    #region Fields
    private Dictionary<Type, Type> _commandHandlerTypes;
    private Dictionary<Type, Type> _validationHandlerTypes;
    private readonly IUnitOfWork _unitOfWork;
    #endregion
    #region Constructors
    /// <summary>
    /// Initializes a new instance of the <see cref="CommandBus"/> class.
    /// </summary>
    public CommandBus(IUnitOfWork unitOfWork)
    {
        // Validate arguments
        if (unitOfWork == null) throw new ArgumentNullException("unitOfWork");
        // Cache the UOW
        _unitOfWork = unitOfWork;
        RegisterAllHandlerTypes();
    }
    #endregion
    #region ICommandBus Members
    /// <summary>
    /// Submits the specified command.
    /// </summary>
    /// <typeparam name="TCommand">The type of the command.</typeparam>
    /// <param name="command">The command.</param>
    /// <returns></returns>
    public ICommandResult Submit<TCommand>(TCommand command) 
        where TCommand : class, ICommand
    {
        Validate(command);
        return SubmitInternal(command);
    }
    #endregion
    #region Methods : private
    /// <summary>
    /// Gets the command handler types.
    /// </summary>
    /// <returns></returns>
    private static Dictionary<Type, Type> GetCommandHandlerTypesFromAssembly()
    {
        // Create a function that will return true if the type is of type ICommandHandler
        Func<Type, bool> isCommandHandler = t => t.GetInterfaces()
           .Any(i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(ICommandHandler<>));
        // Use this function to register the command handlers in this assembly
        Assembly assembly = Assembly.GetCallingAssembly();
        return GetSpecificHandlerTypesFromAssembly(assembly, isCommandHandler);
    }
    /// <summary>
    /// Registers all of the handler types.
    /// </summary>
    private void RegisterAllHandlerTypes()
    {
        _commandHandlerTypes = GetCommandHandlerTypesFromAssembly();
        _validationHandlerTypes = GetValidationHandlerTypesFromAssembly();
    }
    /// <summary>
    /// Gets the specific handler types using the specified function to determine correct types.
    /// </summary>
    /// <param name="assembly">The assembly to get hansdlers from</param>
    /// <param name="isCorrectTypeCallback">A function that returns true if the Type is correct.</param>
    /// <returns></returns>
    private static Dictionary<Type, Type> GetSpecificHandlerTypesFromAssembly(
        Assembly assembly, 
        Func<Type, bool> isCorrectTypeCallback)
    {
        Func<Type, IEnumerable<Tuple<Type, Type>>> collect = t => t.GetInterfaces()
            .Select(i => Tuple.Create(i.GetGenericArguments()[0], t));
        return assembly
            .GetTypes()
            .Where(t => !t.IsAbstract && !t.IsGenericType)
            .Where(isCorrectTypeCallback)
            .SelectMany(collect)
            .ToDictionary(x => x.Item1, x => x.Item2);
    }
    /// <summary>
    /// Gets the validation handlers.
    /// </summary>
    /// <returns></returns>
    private static Dictionary<Type, Type> GetValidationHandlerTypesFromAssembly()
    {
        // Create a function that will return true if the type is of type IValidationHandler
        Func<Type, bool> isValidationHandler = t => t.GetInterfaces()
           .Any(i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IValidationHandler<>));
        // Use this function to register the validation handlers in this assembly
        Assembly assembly = Assembly.GetCallingAssembly();
        return GetSpecificHandlerTypesFromAssembly(assembly, isValidationHandler);
    }
    private ICommandResult SubmitInternal(object command)
    {
        // do some work
    }
    private void Validate<TCommand>(TCommand command)
        where TCommand : class, ICommand
    {
        // Get the command type and check if we have a validator for that type
        Type commandType = command.GetType();
        bool hasValidator = _validationHandlerTypes.ContainsKey(commandType);
        // If we don't have a validator dont worry, just break leve the method
        if (!hasValidator) return;
        // Create and instance of the handler
        Type validatorType = _validationHandlerTypes[commandType];
        var handler = Activator.CreateInstance(validatorType, _unitOfWork);
        Type handlerType = handler.GetType();
        var handlerB = handler as IValidationHandler<TCommand>;
        var handlerC = handler as IValidationHandler<ICommand>;
        //handler.Validate(command); compiler fails as handler is OBJECT
        if (handlerB != null) handlerB.Validate(command);
        if (handlerC != null) handlerC.Validate(command);
    }    
    #endregion
}

我的问题是在Validate()方法，虽然我可以创建我的命令验证器的实例，它显示(悬停在变量上)它是正确的类型(即CompanyAddValidator的实例)，我不能调用Validate()方法，因为它是一个对象。如果我试图将这个处理程序转换为IValidationHandler <ICommand祝辞(即handlerB和handlerC)，所以我可以在接口上调用"Validate()"方法，我得到一个空引用。>

我无法获得允许我需要的泛型级别的正确语法，并且能够在实例化的CompanyAddValidator对象或任何其他域实体验证器上调用Validate()方法。

有谁能给我指个方向吗?我试着照着这些例子去做，但运气不好。 http://stackoverflow.xluat.com/questions/30739865/command-bus-dispatcher-and-handler-registration-without-dependency-injection

我可以使用激活器吗?创建带有接口的实例?

https://alertcoding.wordpress.com/2013/03/18/command-and-query-based-entity-framework-architecture-part-2/comment-page-1/评论- 153

dynamic handler = Activator.CreateInstance(validatorType, _unitOfWork);
handler.Validate((dynamic)command);

handler.GetType().GetMethod("Validate").Invoke(handler,new object[] {command});