[Architect] Abp 原理解析 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**

  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**        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

原标题：[Architect] Abp 原理解析 Validation

关键词：