[Architect] Abp 框架原理解析(4) Validation

本节目录

• 介绍
• DataAnnotations
• ICustomValidate
• IShouldNormalize
• 实现Abp Validation

介绍

Abp中在Application层集成了validation.

直接上代码吧.

DataAnnotations

这是微软提供的一套验证框架,只用引用程序集System.ComponentModel.DataAnnotations.

自带的各种特性标签就不说了,默认在MVC中已集成此验证.

这里说下验证方法:

        static void Main(string[] args)
        {
            var obj = new object();
            var rst = new StringLengthAttribute(10) { MinimumLength = 6 }.GetValidationResult("Never", new ValidationContext(obj) { DisplayName = "名称", MemberName = "Name" });
            Console.WriteLine(rst);
            Console.ReadKey();
        }

运行结果:

ValidationResult对象

在MVC中,obj指的是验证的对象,DisplayName指DisplayName特性的Name值,Member指字段代码名.

ICustomValidate

该接口在标准验证结束后调用.

    public interface ICustomValidate : IValidate
    {
        void AddValidationErrors(List<ValidationResult> results);
    }

通常会如下操作:

    public class CreateTaskInput : IInput, ICustomValidate
    {
        public string Name { get; set; }
        public void AddValidationErrors(List<ValidationResult> results)
        {
            if (Name == "xx")
            {
                results.Add(new ValidationResult("Task 名非法"));
            }
        }
    }

当标准验证功能无法完成某些特定的验证功能,可以使用此接口.

IShouldNormalize

该接口并非验证字段,而是在验证完字段,离开验证过滤器前的时候执行.

一般在此接口做初始化或者其他操作.

    public interface IShouldNormalize
    {
        void Normalize();
    }

如：

    public class CreateTaskInput : IInput, IShouldNormalize
    {
        public string Name { get; set; }
        public void Normalize()
        {
            Name = DateTime.Now.ToShortDateString() + "-task";
        }
    }

　　

实现Abp Validation

在Abp中大致会经历这3个接口.

在这里,仿照Abp验证

先定义接口

    public interface IInput
    {

    }
    public interface IShouldNormalize
    {
        void Normalize();
    }
    public interface ICustomValidate
    {
        void AddValidationErrors(List<ValidationResult> results);
    }

定义Dto

    public class CreateTaskInput : IInput, IShouldNormalize, ICustomValidate
    {
        [StringLength(10, MinimumLength = 5)]
        public string Name { get; set; }

        public void Normalize()
        {
            Name = DateTime.Now.ToShortDateString() + "-task";
        }

        public void AddValidationErrors(List<ValidationResult> results)
        {
            if (Name == "xx")
            {
                results.Add(new ValidationResult("Task 名非法"));
            }
        }
    }

定义ApplicationService

    public interface ITaskAppService
    {
        void CreateTask(CreateTaskInput input);
    }

    public class TaskAppService : ITaskAppService
    {
        public void CreateTask(CreateTaskInput input)
        {
            Console.WriteLine("进入CreateTask方法:" + input.Name);
        }
    }

定义拦截器

    public class ValidateInterceptor : IInterceptor
    {
        public void Intercept(IInvocation invocation)
        {
            new MethodInvocationValidator(invocation.Arguments).Validate();
            invocation.Proceed();
        }
    }

验证逻辑

    internal class MethodInvocationValidator
    {
        private readonly object[] _parameterValues;
        private readonly List<ValidationResult> _validationErrors;

        /// <summary>
        /// Creates a new <see cref="MethodInvocationValidator"/> instance.
        /// </summary>
        /// <param name="parameterValues">List of arguments those are used to call the <paramref name="method"/>.</param>
        public MethodInvocationValidator(object[] parameterValues)
        {
            _parameterValues = parameterValues;
            _validationErrors = new List<ValidationResult>();
        }

        public void Validate()
        {
            //basic validate
            for (var i = 0; i < _parameterValues.Length; i++)
            {
                ValidateObjectRecursively(_parameterValues[i]);
            }
　　　　　　　//throw exception
            if (_validationErrors.Any())
            {
                foreach (var validationResult in _validationErrors)
                {
                    Console.WriteLine("{0}:{1}", validationResult.MemberNames.FirstOrDefault(), validationResult.ErrorMessage);
                }
                throw new Exception("有参数异常");
            }
　　　　　　　//normalize
            foreach (var parameterValue in _parameterValues)
            {
                if (parameterValue is IShouldNormalize)
                {
                    (parameterValue as IShouldNormalize).Normalize();
                }
            }
        }

        private void ValidateObjectRecursively(object validatingObject)
        {
            var properties = TypeDescriptor.GetProperties(validatingObject).Cast<PropertyDescriptor>();
            foreach (var property in properties)
            {
                var validationAttributes = property.Attributes.OfType<ValidationAttribute>().ToArray();
                if (validationAttributes.IsNullOrEmpty())
                {
                    continue;
                }

                var validationContext = new ValidationContext(validatingObject)
                {
                    DisplayName = property.Name,
                    MemberName = property.Name
                };

                foreach (var attribute in validationAttributes)
                {
                    var result = attribute.GetValidationResult(property.GetValue(validatingObject), validationContext);
                    if (result != null)
                    {
                        _validationErrors.Add(result);
                    }
                }
            }
　　　　　　　　//custom validate
            if (validatingObject is ICustomValidate)
            {
                (validatingObject as ICustomValidate).AddValidationErrors(_validationErrors);
            }
        }
    }

　　

执行

        static void Main(string[] args)
        {
            using (var container = new WindsorContainer())
            {
                container.Register(Component.For<IInterceptor, ValidateInterceptor>());//先注入拦截器
                container.Kernel.ComponentRegistered += Kernel_ComponentRegistered;
                container.Register(Component.For<ITaskAppService, TaskAppService>());
                var person = container.Resolve<ITaskAppService>();
                person.CreateTask(new CreateTaskInput() { Name = "123" });
            }
            Console.ReadKey();
        }

        static void Kernel_ComponentRegistered(string key, Castle.MicroKernel.IHandler handler)
        {
            handler.ComponentModel.Interceptors.Add(new InterceptorReference(typeof(ValidateInterceptor)));
        }

将name改成"12345"

本文地址:http://neverc.cnblogs.com/p/5267425.html