使用IValidatableObject验证时获取成员属性 [英] Get member attribute when validating using IValidatableObject

问题描述

我使用IValidatableObject验证在下列情况下一个复杂的对象。

I'm using IValidatableObject to validate a complex object in the following scenario.

public class Foo {
    [Required]
    public Bar Foobar { get; set; }
}

public class Bar : IValidatableObject {
    public int Id { get; set; }
    public string Name { get; set; }
    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)  {
        // check if the current property instance is decorated with the Required attribute
        if(TheAboveConditionIsTrue) {
            // make sure the Name property is not null or empty
        }
    }
}

我不知道这是否是做到这一点的最好办法，如果不是我很高兴承担解决验证等方式的意见。

I don't know if this is the best way to do this, if not I'm happy to take comments on other ways of solving the validation.

推荐答案

创建富的抽象基类，它实现 IValidatableObject ，并使其验证（）虚拟方法：

Create an abstract base class for Foo that implements IValidatableObject and make its Validate() method virtual:

public abstract class FooBase : IValidatableObject
{
    public string OtherProperty { get; set; }

    public Bar Foobar { get; set; }
    public virtual IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        var results = new List<ValidationResult>();

        //Validate other properties here or return null
        if (String.IsNullOrEmpty(OtherProperty))
            results.Add(new ValidationResult("OtherProperty is required", new[] { "OtherProperty" }));

        return results;
    }
}

现在实现你的基类或者 FooRequired 或 FooNotRequired ：

Now implement your base class as either FooRequired or FooNotRequired:

public class FooRequired : FooBase
{
    public override IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        var result = base.Validate(validationContext).ToList();
        result.AddRange(Foobar.Validate(validationContext));
        return result;
    }
}

public class FooNotRequired : FooBase
{
    //No need to override the base validate method.
}

您酒吧类仍然会是这个样子：

Your Bar class would still look something like this:

public class Bar : IValidatableObject
{
    public int Id { get; set; }
    public string Name { get; set; }

    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        var results = new List<ValidationResult>();

        if (String.IsNullOrEmpty(Name))
            results.Add(new ValidationResult("Name is required", new[] { "Name" }));

        return results;
    }
}

用法：

FooBase foo1 = new FooRequired();
foo1.Validate(...);

FooBase foo2 = new FooNotRequired();
foo2.Validate(...);

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