我有一个带有DataAnnotation属性的对象图，其中对象的某些属性是本身具有验证属性的类，依此类推。
在以下场景中：
public class Employee
{
[Required]
public string Name { get; set; }
[Required]
public Address Address { get; set; }
}
public class Address
{
[Required]
public string Line1 { get; set; }
public string Line2 { get; set; }
[Required]
public string Town { get; set; }
[Required]
public string PostalCode { get; set; }
}
如果我试图验证Employee的Address没有PostalCode的值，那么我想（并期望）一个异常，但我没有得到。我是这样做的：
var employee = new Employee
{
Name = "Neil Barnwell",
Address = new Address
{
Line1 = "My Road",
Town = "My Town",
PostalCode = "" // <- INVALID!
}
};
Validator.ValidateObject(employee, new ValidationContext(employee, null, null));
我有什么其他选择与Validator，以确保所有属性递归验证？
提前谢谢了。
我的答案太长了，不能放在这里，所以我把它变成了博客文章:)
Recursive Validation Using DataAnnotations
该解决方案为您提供了一种使用您现在使用的相同基本方法实现递归验证的方法。
这是选择加入属性方法的替代方法。我相信这将正确地遍历对象图并验证一切。
public bool TryValidateObjectRecursive<T>(T obj, List<ValidationResult> results) {
bool result = TryValidateObject(obj, results);
var properties = obj.GetType().GetProperties().Where(prop => prop.CanRead
&& !prop.GetCustomAttributes(typeof(SkipRecursiveValidation), false).Any()
&& prop.GetIndexParameters().Length == 0).ToList();
foreach (var property in properties)
{
if (property.PropertyType == typeof(string) || property.PropertyType.IsValueType) continue;
var value = obj.GetPropertyValue(property.Name);
if (value == null) continue;
var asEnumerable = value as IEnumerable;
if (asEnumerable != null)
{
foreach (var enumObj in asEnumerable)
{
var nestedResults = new List<ValidationResult>();
if (!TryValidateObjectRecursive(enumObj, nestedResults))
{
result = false;
foreach (var validationResult in nestedResults)
{
PropertyInfo property1 = property;
results.Add(new ValidationResult(validationResult.ErrorMessage, validationResult.MemberNames.Select(x => property1.Name + '.' + x)));
}
};
}
}
else
{
var nestedResults = new List<ValidationResult>();
if (!TryValidateObjectRecursive(value, nestedResults))
{
result = false;
foreach (var validationResult in nestedResults)
{
PropertyInfo property1 = property;
results.Add(new ValidationResult(validationResult.ErrorMessage, validationResult.MemberNames.Select(x => property1.Name + '.' + x)));
}
}
}
}
return result;
}
最新代码：https://github.com/reustmd/DataAnnotationsValidatorRecursive
包装：https://www.nuget.org/packages/DataAnnotationsValidator/
此外，我已更新此解决方案以处理循环对象图。感谢您的反馈。
码：
public class DataAnnotationsValidator : IDataAnnotationsValidator
{
public bool TryValidateObject(object obj, ICollection<ValidationResult> results, IDictionary<object, object> validationContextItems = null)
{
return Validator.TryValidateObject(obj, new ValidationContext(obj, null, validationContextItems), results, true);
}
public bool TryValidateObjectRecursive<T>(T obj, List<ValidationResult> results, IDictionary<object, object> validationContextItems = null)
{
return TryValidateObjectRecursive(obj, results, new HashSet<object>(), validationContextItems);
}
private bool TryValidateObjectRecursive<T>(T obj, List<ValidationResult> results, ISet<object> validatedObjects, IDictionary<object, object> validationContextItems = null)
{
//short-circuit to avoid infinite loops on cyclic object graphs
if (validatedObjects.Contains(obj))
{
return true;
}
validatedObjects.Add(obj);
bool result = TryValidateObject(obj, results, validationContextItems);
var properties = obj.GetType().GetProperties().Where(prop => prop.CanRead
&& !prop.GetCustomAttributes(typeof(SkipRecursiveValidation), false).Any()
&& prop.GetIndexParameters().Length == 0).ToList();
foreach (var property in properties)
{
if (property.PropertyType == typeof(string) || property.PropertyType.IsValueType) continue;
var value = obj.GetPropertyValue(property.Name);
if (value == null) continue;
var asEnumerable = value as IEnumerable;
if (asEnumerable != null)
{
foreach (var enumObj in asEnumerable)
{
if ( enumObj != null) {
var nestedResults = new List<ValidationResult>();
if (!TryValidateObjectRecursive(enumObj, nestedResults, validatedObjects, validationContextItems))
{
result = false;
foreach (var validationResult in nestedResults)
{
PropertyInfo property1 = property;
results.Add(new ValidationResult(validationResult.ErrorMessage, validationResult.MemberNames.Select(x => property1.Name + '.' + x)));
}
};
}
}
}
else
{
var nestedResults = new List<ValidationResult>();
if (!TryValidateObjectRecursive(value, nestedResults, validatedObjects, validationContextItems))
{
result = false;
foreach (var validationResult in nestedResults)
{
PropertyInfo property1 = property;
results.Add(new ValidationResult(validationResult.ErrorMessage, validationResult.MemberNames.Select(x => property1.Name + '.' + x)));
}
};
}
}
return result;
}
}
public class ValidateObjectAttribute : ValidationAttribute
{
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var results = new List<ValidationResult>();
var context = new ValidationContext(value, null, null);
Validator.TryValidateObject(value, context, results, true);
if (results.Count != 0)
{
var compositeResults = new CompositeValidationResult(String.Format("Validation for {0} failed!", validationContext.DisplayName));
results.ForEach(compositeResults.AddResult);
return compositeResults;
}
return ValidationResult.Success;
}
}
public class ValidateCollectionAttribute : ValidationAttribute
{
public Type ValidationType { get; set; }
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var collectionResults = new CompositeValidationResult(String.Format("Validation for {0} failed!",
validationContext.DisplayName));
var enumerable = value as IEnumerable;
var validators = GetValidators().ToList();
if (enumerable != null)
{
var index = 0;
foreach (var val in enumerable)
{
var results = new List<ValidationResult>();
var context = new ValidationContext(val, validationContext.ServiceContainer, null);
if (ValidationType != null)
{
Validator.TryValidateValue(val, context, results, validators);
}
else
{
Validator.TryValidateObject(val, context, results, true);
}
if (results.Count != 0)
{
var compositeResults =
new CompositeValidationResult(String.Format("Validation for {0}[{1}] failed!",
validationContext.DisplayName, index));
results.ForEach(compositeResults.AddResult);
collectionResults.AddResult(compositeResults);
}
index++;
}
}
if (collectionResults.Results.Any())
{
return collectionResults;
}
return ValidationResult.Success;
}
private IEnumerable<ValidationAttribute> GetValidators()
{
if (ValidationType == null) yield break;
yield return (ValidationAttribute)Activator.CreateInstance(ValidationType);
}
}
public class CompositeValidationResult : ValidationResult
{
private readonly List<ValidationResult> _results = new List<ValidationResult>();
public IEnumerable<ValidationResult> Results
{
get
{
return _results;
}
}
public CompositeValidationResult(string errorMessage) : base(errorMessage) { }
public CompositeValidationResult(string errorMessage, IEnumerable<string> memberNames) : base(errorMessage, memberNames) { }
protected CompositeValidationResult(ValidationResult validationResult) : base(validationResult) { }
public void AddResult(ValidationResult validationResult)
{
_results.Add(validationResult);
}
}
public interface IDataAnnotationsValidator
{
bool TryValidateObject(object obj, ICollection<ValidationResult> results, IDictionary<object, object> validationContextItems = null);
bool TryValidateObjectRecursive<T>(T obj, List<ValidationResult> results, IDictionary<object, object> validationContextItems = null);
}
public static class ObjectExtensions
{
public static object GetPropertyValue(this object o, string propertyName)
{
object objValue = string.Empty;
var propertyInfo = o.GetType().GetProperty(propertyName);
if (propertyInfo != null)
objValue = propertyInfo.GetValue(o, null);
return objValue;
}
}
public class SkipRecursiveValidation : Attribute
{
}
public class SaveValidationContextAttribute : ValidationAttribute
{
public static IList<ValidationContext> SavedContexts = new List<ValidationContext>();
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
SavedContexts.Add(validationContext);
return ValidationResult.Success;
}
}