ModelValidator主要是应用在ModelMetadata元数据的类型上或类型属性上。它是验证的基础类型，所有的ModelValidatorProviders、DataAnnotationValidator、DataAnnotationValidatorProvider都是主要通过GetValidators这个方法来获取IEnumerable<ModelValidator>对象。然后循环这个迭代对象，利用ModelValidator的Validator对每个元数据进行验证。有个例子可以很好的说明：
private IEnumerable<ModelValidator> GetValidator(Type type)
{
ModelValidatorProvider provider=new DataAnnodationModelValidatorProvider();
ModelMetaData metadata=ModelMetadataProviders.Current.GetMetadataForType(null,type);
foreach(var validator in provider.GetValidator(metadata,ControllerContext))
{
yeild return validator
} foreach(var propertyMetadata in metadata.Properties)
{
foreach(var validator in provider.GetValidator(propertyMetadata,ControllerContext))
yeild return validator;
}
}
元数据ModelMetaData包含：IEnumrable<ModelValidator> GetValidator(ContollerContext) 实现方法：
IEnumrable<ModelValidator> GetValidator(ControllerContext context)
{
return ModelValidatorProviders.Providers.GetValidator(this,context)
}
其中Providers来源：
private static readonly ModelValidatorProviderCollection _providers=new ModelValidatorProviderCollecton
{
new DataAnnotationModelValidatorProvider(),
new DataErrorInfoModelValidatorProvider(),
new ClinetDataTypeModelValidatorProvider()
}
继续实现 Providets的GetValidator的方法：
public class ModelValidatorProviderCollection:ICollection<ModelValidatorProvider>
{
public IEnumrable<ModelValidator> GetValidator(ModelMedatata modeltadata,ControllerContext context)
{
return this.CombindItems.SelectMany(ModelValidatorProvider provider)=>provider.GetValidators(modeltadata,context);
//这个方法CombindItems可理解为内部已定义数据集合和外部自定义的数据集合的合计。具体的实现在MultiServiceResolver：IResolver<IEnumrable<TServerice>>中
}
//对了这个类我本来不想往下记录下 但是为了以后再学习和本着研究的心态还是硬着头皮写写去吧
public IResolver<IEnumrable<ModelValidatorProvider>> _serviceResolver;
privite IEnumeable<ModelValidator> CombindItems
{
get{
return this._serviceResoler.Current;
}
}
public ModelValidatorProviderCollection()
{
this._serviceResolver=new MultiServiceResolver<ModelValidatorProvider>(()=>this.Items);
}
public ModelValidatorProviderCollection(IList<ModelValidatorProvider> list):base(list);
{
this._serviceResolver=new MultiServerResolver<ModelValdatorProvider>(()=>this.Items);
}
internal ModelValidatorProviderCollection(IReslover<IEnumrable<ModelValidatorProvider>> services,Params ModelValidatorProvider[] modelValidatorProviders):base(modelValidatorProviders)
{
IResolver<IEnumrable<ModelValidaotProvider>> arge=services;
if(arge==null)
{
arge=new MultiServiceReslover<ModelValidatorProvider>(this.Items);
}
this._serviceResolber=arge;
}
prottect override void SetItem(int index,ModelValidatorProvider item)
{
if(item==null)
throw new ArgumentNullException("item");
base.SetItem(index,item);
}
}//【下面要介绍的是MultiServiceResolver类的只要实现，主要是通过依赖组件DependencyResolver.Current的GerServices<TService>得到一组数据，然后通过构造函数传入的委托方法得到另外一组数据，通过Current实现两组数据的结合】
public class MultiServiceReslover<TService>:IService<IEnumrable<TService>> where TService :Class
{
private Lazy<IEnumerable<TService>> _itemsFormService;
private Func<IEnumrable<IService>> _itemThunk;
private Func<IEnumrable<TService>> _resolverThunk;
public IEnumrable<TService> Current
{
get{
return this.itemsFormService.Value.Cacat(this._itemThunk());
}
}
public MultiServiceResolve(Func<IEnumrable<TService>> itemsThunk)
{
if(itemThunk==null)
throw new ArgumentNullException("itemThunk");
this._itemsThunk=itemsThunk;
this._resolverThunk=(()=>DependencyResolver.Curremt);
this._itemsFormServices=new Lazy<IEnumerable<TService>>(()=>this._resolverThunk.GetService<TService>());
}
}
前面一直围绕着获取ModelValidatorProvider来实现方法。可ModelValidatorProvider本身是一个抽象类和只有一个abstract的GetValidators(ModelMedata，ControllerContext)的方法。现在对系统中默认继承和实现ModelValidatorProvider抽象类的其中一个比较常用的类型做说明，那就是 DataAnnotationModelValidatorProvider，它是系统间接实现了ModelValidatorProvider，是我们最常用的基于验证特性的声明式 Model 验证。
在了解DataAnnotationModelValidatorProvider时 会提到DataAnnotationModelValidator这类，它具体地实现了ModelValidator定义的方法（包括Validate（object container））。
public class DataAnnotationModelValidatorProvider:AssocitatedValidatorProvider
{
//这里只编辑主要的实现方法 // 这里的DataAnnotationModelValidatorFactory的系统定义的一个委托。如果元数据属性未定义在AttributeFactories中 则采用默认的ModelValidator对象
internal static DataAnnotationModelValidatorFactory DefaultAttributeFactory=(ModelMetaData metadata,ControllerContext context,ValidatorAttribute attrubute)=>new DataAnnotaionModelValidator(metadata,context,attribute); //主要为创建元数据"自我验证"集合,可以通过RegisterValidatableObjectAdapter（Type modelType,Type adapterType）来实现自我注册
internal static Dictionary<Type,DataAnnotationModelValidatorFactiory> AttributeFactories=DataAnnotationModelValidatorProvider.BuildAttributeFactoriesDictionary(); //接下来是最主要的代码了
protext override IEnumerable<ModelValidator> GetValidators(ModelMetaData metadata,ControllerContext context,ValidatorAttribute attributes)
{
var result=new List<ModelValidator>;
try{
//这一步的意思是： AddImplicitRequiredAttributeForValueTypes （为值类型添加隐式必填验证） 值为True,元数据也声明了Required=True,则必须在attributes里包含 RequiredAttribute if(DataAnnotatoonModelValidatorProvider.AddImplicitRequiredAttributeForValueType && metadata.IsRequired)
{
if(!attributes.Any((Attribute t)=>t is RequiredAttribute))
{
attrubutes=attribites.concat(new RequiredAttribute[]{new RequiredAttrbute()});
}
}
foreach(var ValidatorAttribute current in attributes.ofType<ValidatorAttribute>)
{
DataAnnotationModelValidatorFactory defaultFactory;
if(!DataAnnotationModelValidatorProvider.AttrbuteFactories.TryValue(current.GetType(),out defualtFactory))
{
defaultFactory=DataAnnotationModelValidatorProvider.DefaultAttrbuteFactoty;
}
result.Add(defaultFactory(metadata,context,current))
}
if(typeof(IValidatableObject).IsAssignableForm(medatat.ModelType))
{
DataAnnotationsValidatableObjectAdapterFactory defaultValidatableFactory;
if (!DataAnnotationsModelValidatorProvider.ValidatableFactories.TryGetValue(metadata.ModelType, out defaultValidatableFactory))
{
defaultValidatableFactory = DataAnnotationsModelValidatorProvider.DefaultValidatableFactory;
}
result.Add(defaultValidatableFactory(metadata, context)); }
}
finally{ }
return result;
}
//上面这个方法写了这么多无非就是 根据元数据上的属性获取继承了ModelValidator的对象集合，然后利用集合里每个对象所定义的Validator方法进行验证
//下面是一些自定义注册方法 public static void RegistAdapter(Type attrbuteType,Type adaperType)
{
//获取当前 adaperType的特定构造函数
ConstructorInfo constructor=adapterType.GetConstructor(typeOf(ModelMetadata),typeof(ControllerContext),attrbuteType);
try{
DataAnnotationModelValidatorProvider.AttributeFacties[attrbuteType]=((ModelMedatada metadata,ControllerContext context,ValidatorAttribute attribute)=>(ModelValidator)constructor.Invoker(new object[]{metadata,context,attrbute}));
}
finally{
}
}//直接用委托方法注册
public static void RegisterAdapterFactory(Type attributeType,DataAnnotationsModelValidatorFactory factory) BuildAttributeFacoriesDictionary
{
//还有好多自定义注册方法 反编译后查看吧
//下面实现的是系统自定义一些ValidatorAttribute
private static Dictionary<Type,DataAnnotationModelValidatorFactory> dictionary=new Dictionary<Type,DataAnnotationModelValidatorFactory>();
DataAnnotationsModelValidatorProvider.AddValidationAttributeAdapter(dictionary, typeof(RangeAttribute), (ModelMetadata metadata, ControllerContext context, ValidationAttribute attribute) => new RangeAttributeAdapter(metadata, context, (RangeAttribute)attribute));
DataAnnotationsModelValidatorProvider.AddValidationAttributeAdapter(dictionary, typeof(RegularExpressionAttribute), (ModelMetadata metadata, ControllerContext context, ValidationAttribute attribute) => new RegularExpressionAttributeAdapter(metadata, context, (RegularExpressionAttribute)attribute));
DataAnnotationsModelValidatorProvider.AddValidationAttributeAdapter(dictionary, typeof(RequiredAttribute), (ModelMetadata metadata, ControllerContext context, ValidationAttribute attribute) => new RequiredAttributeAdapter(metadata, context, (RequiredAttribute)attribute));
DataAnnotationsModelValidatorProvider.AddValidationAttributeAdapter(dictionary, typeof(StringLengthAttribute), (ModelMetadata metadata, ControllerContext context, ValidationAttribute attribute) => new StringLengthAttributeAdapter(metadata, context, (StringLengthAttribute)attribute));
DataAnnotationsModelValidatorProvider.AddValidationAttributeAdapter(dictionary, ValidationAttributeHelpers.MembershipPasswordAttributeType, (ModelMetadata metadata, ControllerContext context, ValidationAttribute attribute) => new MembershipPasswordAttributeAdapter(metadata, context, attribute));
DataAnnotationsModelValidatorProvider.AddValidationAttributeAdapter(dictionary, ValidationAttributeHelpers.CompareAttributeType, (ModelMetadata metadata, ControllerContext context, ValidationAttribute attribute) => new CompareAttributeAdapter(metadata, context, attribute));
DataAnnotationsModelValidatorProvider.AddValidationAttributeAdapter(dictionary, ValidationAttributeHelpers.FileExtensionsAttributeType, (ModelMetadata metadata, ControllerContext context, ValidationAttribute attribute) => new FileExtensionsAttributeAdapter(metadata, context, attribute));
DataAnnotationsModelValidatorProvider.AddDataTypeAttributeAdapter(dictionary, ValidationAttributeHelpers.CreditCardAttributeType, "creditcard");
DataAnnotationsModelValidatorProvider.AddDataTypeAttributeAdapter(dictionary, ValidationAttributeHelpers.EmailAddressAttributeType, "email");
DataAnnotationsModelValidatorProvider.AddDataTypeAttributeAdapter(dictionary, ValidationAttributeHelpers.PhoneAttributeType, "phone");
DataAnnotationsModelValidatorProvider.AddDataTypeAttributeAdapter(dictionary, ValidationAttributeHelpers.UrlAttributeType, "url");
return dictionary;
}
}
上面这个类引用了之类AssociatedValidatorProvider Associated(关联的意思)。这个类首先利用GetValidator(ModelMetadata,ControllerContext) 对元数据提取Attribute, 得到的Attribute数组去调用抽象方法GetValidator(ModelMetadata,ControllerContext,IEnumrable<ModelValidator>)，这个方法在上面的DataAnnotationModelValidatorProvider被实现。
AssociatedValidatorProvider类重点对传入的元数据ModelMetadata进行解析。
public sealed override IEnumerable<ModelValidator> GetValidators(ModelMetadata metadata,ControllerContext context)
{
if(metadata==null)
throw new ArgumentNullExecption("metadata");
if(context==null)
throw new ArgumentNullExecption("context");}
protect abstract IEnumrable<ModelValidator> GetValidators(ModelMetadata,ControllerContext,IEunmerable<Attribute> atttibutes);//这个抽象方法在上面类（DataAnnotationModelValidatorProvider）里有具体的实现protected override ICustomTypeDescriptor GetTypeDescriptor(Type type)
{
return TypeDescriptorHepler.Get(type);
} pritvate IEnumerable<ModelValidator> GetValidatorForProperty(ModelMetadata metadata,ControllerContextg context)
{
IcustomTypeDescriptor typedescriptor=this.GetTypeDescriptor(metadata.ContainerType);
PropertyDescriptor propertyDescriptor=typedescriptor.GetProperties.Find(metadata.PropertyName,true);
if(propertyDescriptor==null)
throw new ArgumentException("PropertyNoFound")；
return this.GetValidator(metadata,context,propertyDescriptor.Attributes.OfType<Attribute>);
}private IEnumerable<ModelValidator> GetValidatorsForType(MedelMetadata metadata,ControllerContext context)
{
return this.GetValidator(metadata,context,this.GetTypeDescriptor(metadata.ModelType).GetAttributes().Cast<Attribue>);
}
上面的DataAnnotationModelValidatorProvider中 根据属性来查找实现委托DataAnnotationsModelValidationFactory时，有一个默认的实现：DataAnnotationsModelValidator。这个方法是真正实现了验证功能Validate(object contatiner).
下面就是这个类大概的实现过程。
public class DataAnnotationModelValidator:ModelValidator
{
public override IEnumerable<ModelValidatorResult> Validate(object container)
{
ValidationContext validationContext=new ValidationContext(container??base.Metadata.Model,null,null);
validationContext.DisplayName=this.Metadata.DisPlayName();
validationResult result=this.Attribute.GetValidationResult(base.Metadata.Model,validationContext);
if(result!=result.Scuess)
{
yeild return New ModelValidateResult
{
Message=validation.ErrorMessage;
};
yeild break;
}
} protect internal string ErrorMessage
{
get{
return this.Attribute.FormatErrorMessage(base.Metadata.DispalyName());
}
}
}
