领域Command

一、项目结构

 

二、代码

    /// <summary>
    /// 
    /// </summary>
    public interface ICommand
    {
    }

    /// <summary>
    /// 
    /// </summary>
    public interface ICommandResult
    {
        bool Success { get; }
        int? ReturnKey { get; }

        string ReturnKeys { get; }

    }

    /// <summary>
    /// 
    /// </summary>
    /// <typeparam name="TCommand"></typeparam>
    public interface ICommandHandler<in TCommand> where TCommand : ICommand
    {
        ICommandResult Execute(TCommand command);
    }

    /// <summary>
    /// 
    /// </summary>
    /// <typeparam name="TCommand"></typeparam>
    public interface IValidationHandler<in TCommand> where TCommand : ICommand
    {
        IEnumerable<ValidationResult> Validate(TCommand command);
    }

    /// <summary>
    /// 
    /// </summary>
    public class CommandResult : ICommandResult
    {
        public CommandResult(bool success, int? returnkey = null, string returnKeys = null)
        {
            this.Success = success;
            this.ReturnKey = returnkey;
            this.ReturnKeys = returnKeys;
        }

        public bool Success { get; protected set; }

        public int? ReturnKey { get; protected set; }

        public string ReturnKeys { get; protected set; }

    }

    /// <summary>
    /// 
    /// </summary>
    public class CommandHandlerNotFoundException : Exception
    {
        public CommandHandlerNotFoundException(Type type)
            : base(string.Format("Command handler not found for command type: {0}", type))
        {
        }
    }

    /// <summary>
    /// 
    /// </summary>
    public class ValidationHandlerNotFoundException : Exception
    {
        public ValidationHandlerNotFoundException(Type type)
            : base(string.Format("Validation handler not found for command type: {0}", type))
        {
        }
    }

    /// <summary>
    /// 
    /// </summary>
    public interface ICommandBus
    {
        ICommandResult Submit<TCommand>(TCommand command) where TCommand : ICommand;
        IEnumerable<ValidationResult> Validate<TCommand>(TCommand command) where TCommand : ICommand;
    }

    /// <summary>
    /// 
    /// </summary>
    public class DefaultCommandBus : ICommandBus
    {
        public ICommandResult Submit<TCommand>(TCommand command) where TCommand : ICommand
        {
            var handler = (ICommandHandler<TCommand>)DependencyDefaultInstanceResolver.GetInstance(typeof(ICommandHandler<TCommand>));
            if (!((handler != null) && handler is ICommandHandler<TCommand>))
            {
                throw new CommandHandlerNotFoundException(typeof(TCommand));
            }   
            return handler.Execute(command);
        }

        public IEnumerable<ValidationResult> Validate<TCommand>(TCommand command) where TCommand : ICommand
        {
            var handler = (IValidationHandler<TCommand>)DependencyDefaultInstanceResolver.GetInstance(typeof(IValidationHandler<TCommand>));
            if (!((handler != null) && handler is IValidationHandler<TCommand>))
            {
                throw new ValidationHandlerNotFoundException(typeof(TCommand));
            }
            return handler.Validate(command);
        }

    }

 

    /// <summary>
    /// Describes the result of a validation of a potential change through a business service.
    /// </summary>
    public class ValidationResult
    {

        /// <summary>
        /// Initializes a new instance of the <see cref="ValidationResult"/> class.
        /// </summary>
        public ValidationResult()
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="ValidationResult"/> class.
        /// </summary>
        /// <param name="memeberName">Name of the memeber.</param>
        /// <param name="message">The message.</param>
        public ValidationResult(string memeberName, string message)
        {
            this.MemberName = memeberName;
            this.Message = message;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="ValidationResult"/> class.
        /// </summary>
        /// <param name="message">The message.</param>
        public ValidationResult(string message)
        {
            this.Message = message;
        }

        /// <summary>
        /// Gets or sets the name of the member.
        /// </summary>
        /// <value>
        /// The name of the member.  May be null for general validation issues.
        /// </value>
        public string MemberName { get; set; }

        /// <summary>
        /// Gets or sets the message.
        /// </summary>
        /// <value>
        /// The message.
        /// </value>
        public string Message { get; set; }

    }

 

三、使用示例

注册

            builder.RegisterType<DefaultCommandBus>().As<ICommandBus>().InstancePerLifetimeScope();

            var domainCommands = Assembly.Load("Frozen.DomainCommands");
            builder.RegisterAssemblyTypes(domainCommands)
                .AsClosedTypesOf(typeof(ICommandHandler<>)).InstancePerLifetimeScope();
            builder.RegisterAssemblyTypes(domainCommands)
                .AsClosedTypesOf(typeof(IValidationHandler<>)).InstancePerLifetimeScope();

定义Command

    /// <summary>
    /// Command 删除学生
    /// </summary>
    public class DeleteStudentCommand : ICommand
    {
        /// <summary>
        /// 学生Id
        /// </summary>
        public int StuId { get; set; }

    }

定义Handler

    /// <summary>
    /// 
    /// </summary>
    public class DeleteStudentHandler : ICommandHandler<DeleteStudentCommand>
    {
        private readonly IStuEducationRepo _iStuEducationRepo;

        public DeleteStudentHandler(IStuEducationRepo iStuEducationRepo)
        {
            this._iStuEducationRepo = iStuEducationRepo;
        }

        public ICommandResult Execute(DeleteStudentCommand command)
        {


            return new CommandResult(true);
        }

    }

调用

            var command = new DeleteStudentCommand()
            {
                StuId = 1
            };
            var result = _commandBus.Submit(command);

结果：

 

附：源码下载