ModelValidatorProviders基于页面

Question

我已经创建了自定义ModelValidatorProvider，它应该仅在网站中的某些特定操作中处于活动状态。 为了做到这一点，我创建了一个自定义属性，它扩展了“FilterAttribute”，并在OnAuthorize中设置了验证器。

在filter属性中 - 为了只在需要的页面设置验证器，我这样做（PostAttributeModelValidatorProvider是验证器提供者）。

 var provider = (from p in ModelValidatorProviders.Providers 
         where p is PostAttributeModelValidatorProvider 
         select p).FirstOrDefault(); 
     if (provider != null) 
     { 
      ModelValidatorProviders.Providers.Remove(provider); 
     } 

     if (EnableAttributesValidation) 
     { 
      ModelValidatorProviders.Providers.Add(new PostAttributeModelValidatorProvider() { BypassRequiredFieldsValidation = this.BypassRequiredFieldsValidation }); 
     } 

我面临的问题是，有时（我无法检测到什么时候出了问题 - 但我认为，当两种用途尝试访问的网站或触发这个动作的页面时）还有就是我在做正因为这样的删除和添加操作之间的冲突 - 我得到一个错误：

Index was outside the bounds of the array.

相关的堆栈跟踪是：

[IndexOutOfRangeException: Index was outside the bounds of the array.] System.Collections.Generic.Enumerator.MoveNext() +112
System.Linq.d_71 1.MoveNext() +643
System.Linq.<SelectManyIterator>d__14 2.MoveNext() +578
System.Linq.d_14 2.MoveNext() +578
System.Web.Mvc.UnobtrusiveValidationAttributesGenerator.GetValidationAttributes(IEnumerable 1 clientRules, IDictionary 2 results) +440
System.Web.Mvc.HtmlHelper.GetUnobtrusiveValidationAttributes(String name, ModelMetadata metadata) +280
System.Web.Mvc.Html.InputExtensions.InputHelper(HtmlHelper htmlHelper, InputType inputType, ModelMetadata metadata, String name, Object value, Boolean useViewData, Boolean isChecked, Boolean setId, Boolean isExplicitValue, String format, IDictionary 2 htmlAttributes) +1050
System.Web.Mvc.Html.InputExtensions.TextBoxFor(HtmlHelper 1 htmlHelper, Expression 1 expression, String format, IDictionary`2 htmlAttributes) +202 ASP._Page_Views_Home_Index_cshtml.Execute() in c:\interpub\wwwroot\Views\Home\Index.cshtml:47

共该属性mplete源代码是：

public class InitializePostAttributesResolverAttribute : FilterAttribute, IAuthorizationFilter 
{ 
    public InitializePostAttributesResolverAttribute() 
     : this(true, false) 
    { 

    } 

    public InitializePostAttributesResolverAttribute(bool enableAttributesValidation, bool bypassRequiredFieldsValidation) 
    { 
     this.EnableAttributesValidation = enableAttributesValidation; 
     this.BypassRequiredFieldsValidation = bypassRequiredFieldsValidation; 
    } 

    /// <summary> 
    /// Should the attributes input be validated 
    /// </summary> 
    public bool EnableAttributesValidation { get; set; } 


    /// <summary> 
    /// Gets or sets the value whether we should bypass the required fields validation 
    /// </summary> 
    /// <remarks> 
    /// This value should be set to true only if you would like to skip on required fields validation. 
    /// We should use this value when searching. 
    /// </remarks> 
    public bool BypassRequiredFieldsValidation { get; set; } 

    public virtual void OnAuthorization(AuthorizationContext filterContext) 
    { 
     if (filterContext == null) 
     { 
      throw new ArgumentNullException("filterContext"); 
     } 

     ModelMetadataProviders.Current = new PostAttributeModelMetadataProvider(); 

     var provider = (from p in ModelValidatorProviders.Providers 
         where p is PostAttributeModelValidatorProvider 
         select p).FirstOrDefault(); 
     if (provider != null) 
     { 
      ModelValidatorProviders.Providers.Remove(provider); 
     } 

     if (EnableAttributesValidation) 
     { 
      ModelValidatorProviders.Providers.Add(new PostAttributeModelValidatorProvider() { BypassRequiredFieldsValidation = this.BypassRequiredFieldsValidation }); 
     } 
    } 
} 

而且样品使用它

// 
    // POST: /Post/Publish/5 

    [InitializePostAttributesResolver] 
    [HttpPost] 
    [ValidateAntiForgeryToken] 
    public ActionResult Publish(PublishViewModel model) 
    { 
     if (ModelState.IsValid) 
     { 
      // ... 
     } 
    } 

难道我这样做对吗？我的目标（只是要明确）是仅在装饰操作中启用验证程序提供程序，而在验证程序提供程序集合中应该不存在其他操作。

谢谢！

Answer 1

ModelValidatorProviders.Providers是一个静态属性，所以你不能通过这种方式实现线程安全。

相反，您应该在启动时将自定义的ModelValidatorProvider添加到列表中，但使提供程序依赖于模型上的特定属性或其属性（与DataAnnotation属性的逻辑相同）。

[MyCustomValidation] 
public class MyModel 
{ 
    public string MyProperty { get; set; } 
} 

而这应该做的伎俩。