Asp.net Web Api嵌套模型验证

Question

我在asp.net web api的模型绑定和验证(通过数据注释)中遇到了一些问题.

好像我有一个属性的模型,如

Dictionary<string, childObject> obj { get; set; }

childObject的验证似乎没有触发.数据从json与Json.Net序列化器绑定.

是否有一些解决方法或修复此问题？或者我误解了与此相关的其他内容？

---

我不禁想知道为什么这不会导致错误:

public class Child
{        
    [Required]
    [StringLength(10)]
    public string name;
    [Required]
    [StringLength(10)]
    public string desc;     
}

//elsewhere
Child foo = new Child();
foo.name = "hellowrodlasdasdaosdkasodasasdasdasd";

List<ValidationResult> results = new List<ValidationResult>();
Validator.TryValidateObject(foo, new ValidationContext(foo), results, true);
// results.length == 0 here.

---

天啊.我忘了声明属性而不是字段.

Answer 1

有两种方法可以设置字典值的验证.如果您不关心获取所有错误,只是遇到第一个错误,您可以使用自定义验证属性.

public class Foo
{
    [Required]
    public string RequiredProperty { get; set; }

    [ValidateDictionary]
    public Dictionary<string, Bar> BarInstance { get; set; }
}

public class Bar
{
    [Required]
    public string BarRequiredProperty { get; set; }
}

public class ValidateDictionaryAttribute : ValidationAttribute
{
    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        if (!IsDictionary(value)) return ValidationResult.Success;

        var results = new List<ValidationResult>();
        var values = (IEnumerable)value.GetType().GetProperty("Values").GetValue(value, null);
        values.OfType<object>().ToList().ForEach(item => Validator.TryValidateObject(item, new ValidationContext(item, null, validationContext.Items), results));
        Validator.TryValidateObject(value, new ValidationContext(value, null, validationContext.Items), results);
        return results.FirstOrDefault() ?? ValidationResult.Success;
    }

    protected bool IsDictionary(object value)
    {
        if (value == null) return false;
        var valueType = value.GetType();
        return valueType.IsGenericType && valueType.GetGenericTypeDefinition() == typeof (Dictionary<,>);
    }
}

另一种方法是创建自己的字典作为IValidatableObject并进行验证.此解决方案使您能够返回所有错误.

public class Foo
{
    [Required]
    public string RequiredProperty { get; set; }

    public ValidatableDictionary<string, Bar> BarInstance { get; set; }
}

public class Bar
{
    [Required]
    public string BarRequiredProperty { get; set; }
}

public class ValidatableDictionary<TKey, TValue> : Dictionary<TKey, TValue>, IValidatableObject
{
    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        var results = new List<ValidationResult>();
        Values.ToList().ForEach(item => Validator.TryValidateObject(item, new ValidationContext(item, null, validationContext.Items), results));
        return results;
    }
}