如何在FluentValidation中使用反射？

我有一個scneario，我想用反射來使用FluentValidation進行驗證。成纔是這樣的：對象的如何在FluentValidation中使用反射？

public class FooValidator : AbstractValidator<Foo> 
{ 
    public FooValidator(Foo obj) 
    { 
     // Iterate properties using reflection 
     var properties = ReflectionHelper.GetShallowPropertiesInfo(obj); 
     foreach (var prop in properties) 
     { 
      // Create rule for each property, based on some data coming from other service... 
      //RuleFor(o => o.Description).NotEmpty().When(o => // this works fine when foo.Description is null 
      RuleFor(o => o.GetType().GetProperty(prop.Name)).NotEmpty().When(o => 
      { 
       return true; // do other stuff... 
      }); 
     } 
    } 
}

的調用ReflectionHelper.GetShallowPropertiesInfo(obj)回報「淺」的屬性。然後，爲每個屬性創建一個規則。這是我對象獲取屬性代碼：

public static class ReflectionHelper 
{ 
    public static IEnumerable<PropertyInfo> GetShallowPropertiesInfo<T>(T o) where T : class 
    { 

     var type = typeof(T); 
     var properties = 
      from pi in type.GetProperties(BindingFlags.Public | BindingFlags.Instance) 
      where pi.PropertyType.Module.ScopeName == "CommonLanguageRuntimeLibrary" 
       && !(pi.PropertyType.IsGenericType && pi.PropertyType.GetGenericTypeDefinition() == typeof(ICollection<>)) 
      select pi; 

     return properties; 
    } 
}

此代碼編譯並可以執行

IValidator<Foo> validator = new FooValidator(foo); 
var results = validator.Validate(foo);

但它不能正常工作（驗證永遠不會失敗）。有什麼辦法可以做到這一點？

注意：演示代碼，可以發現INT在Github上FluentValidationReflection

來源

2016-03-08 Jose Alonso Monge

最後我找到一個可行的解決方案。我創建了一個接收參數的PropertyInfo自定義PropertyValidator：

public class CustomNotEmpty<T> : PropertyValidator 
{ 
    private PropertyInfo _propertyInfo; 

    public CustomNotEmpty(PropertyInfo propertyInfo) 
     : base(string.Format("{0} is required", propertyInfo.Name)) 
    { 
     _propertyInfo = propertyInfo; 
    } 

    protected override bool IsValid(PropertyValidatorContext context) 
    { 
     return !IsNullOrEmpty(_propertyInfo, (T)context.Instance); 
    } 

    private bool IsNullOrEmpty(PropertyInfo property, T obj) 
    { 
     var t = property.PropertyType; 
     var v = property.GetValue(obj); 

     // Omitted for clarity... 
    } 
}

而對於IRuleBuilder一個擴展方法：

public static class ValidatorExtensions 
{ 
    public static IRuleBuilderOptions<T, T> CustomNotEmpty<T>(
     this IRuleBuilder<T, T> ruleBuilder, PropertyInfo propertyInfo) 
    { 
     return ruleBuilder.SetValidator(new CustomNotEmpty<T>(propertyInfo)); 
    } 
}

有了這個，我可以改變我的FooValidator如下：

public class FooValidator : AbstractValidator<Foo> 
{ 
    public FooValidator(Foo obj) 
    { 
     // Iterate properties using reflection 
     var properties = ReflectionHelper.GetShallowPropertiesInfo(obj); 
     foreach (var prop in properties) 
     { 
      // Create rule for each property, based on some data coming from other service... 
      RuleFor(o => o) 
       .CustomNotEmpty(obj.GetType().GetProperty(prop.Name)) 
       .When(o => 
      { 
       return true; // do other stuff... 
      }); 
     } 
    } 
}

現在我可以使用Reflection來爲特定屬性添加規則

來源

2016-03-09 12:21:18

如何在FluentValidation中使用反射？

回答

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