RequiredIf Boolean，String和FileUpload的验证属性

Question

有人可以给我写一个验证属性的示例，该验证属性验证可能是布尔值，字符串或HttpPostedFile值的从属字段。我一直在寻找，但我尝试过的例子并不适用于所有这些情况。例如，或者如果你能弄清楚我的页面在验证后没有提交的原因 - 这是示例link here的链接

E.g。 1如果UseReferenceId为false，则使用部门图像

public bool UserReferenceId { get; set; }

[RequiredIf("UseReferenceId", false, ErrorMessage="Error please select a Advert image")]
public HttpPostedFileBase DepartmentImageFile { get; set; }

E.g 2

[RequiredIf("AdvertLink", "*", ErrorMessage="Please enter a url for the Image")]
public HttpPostedFileBase AdvertImageFile { get; set; }

[RequiredIf("AdvertImageFile", "*", ErrorMessage="Error please select a Advert image")]
public HttpPostedFileBase AdvertLink { get; set; }

我一直在使用此代码，但我的网页在验证完成后仍未提交。

data-val-requiredif="Url is required for advertisement url." 
data-val-requiredif-dependentproperty="UseReferenceId" data-val-requiredif-targetvalue="false"

public class RequiredIfAttribute : ValidationAttribute, IClientValidatable
{
    protected RequiredAttribute _innerAttribute;

    public string DependentProperty { get; set; }
    public object TargetValue { get; set; }

    public bool AllowEmptyStrings
    {
        get
        {
            return _innerAttribute.AllowEmptyStrings;
        }
        set
        {
            _innerAttribute.AllowEmptyStrings = value;
        }
    }

    public RequiredIfAttribute(string dependentProperty, object targetValue)
    {
        _innerAttribute = new RequiredAttribute();
        DependentProperty = dependentProperty;
        TargetValue = targetValue;
    }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        // get a reference to the property this validation depends upon
        var containerType = validationContext.ObjectInstance.GetType();
        var field = containerType.GetProperty(DependentProperty);

        if (field != null)
        {
            // get the value of the dependent property
            var dependentValue = field.GetValue(validationContext.ObjectInstance, null);
            // trim spaces of dependent value
            if (dependentValue != null && dependentValue is string)
            {
                dependentValue = (dependentValue as string).Trim();

                if (!AllowEmptyStrings && (dependentValue as string).Length == 0)
                {
                    dependentValue = null;
                }
            }

            // compare the value against the target value
            if ((dependentValue == null && TargetValue == null) ||
                (dependentValue != null && (TargetValue.Equals("*") || dependentValue.Equals(TargetValue))))
            {
                // match => means we should try validating this field
                if (!_innerAttribute.IsValid(value))
                    // validation failed - return an error
                    return new ValidationResult(FormatErrorMessage(validationContext.DisplayName), new[] { validationContext.MemberName });
            }
        }

        return ValidationResult.Success;
    }

    public virtual IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var rule = new ModelClientValidationRule
        {
            ErrorMessage = FormatErrorMessage(metadata.GetDisplayName()),
            ValidationType = "requiredif",
        };

        string depProp = BuildDependentPropertyId(metadata, context as ViewContext);

        // find the value on the control we depend on;
        // if it's a bool, format it javascript style 
        // (the default is True or False!)
        string targetValue = (TargetValue ?? "").ToString();
        if (TargetValue is bool)
            targetValue = targetValue.ToLower();

        rule.ValidationParameters.Add("dependentproperty", depProp);
        rule.ValidationParameters.Add("targetvalue", targetValue);

        yield return rule;
    }

    private string BuildDependentPropertyId(ModelMetadata metadata, ViewContext viewContext)
    {
        // build the ID of the property
        string depProp = viewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(DependentProperty);
        // unfortunately this will have the name of the current field appended to the beginning,
        // because the TemplateInfo's context has had this fieldname appended to it. Instead, we
        // want to get the context as though it was one level higher (i.e. outside the current property,
        // which is the containing object, and hence the same level as the dependent property.
        var thisField = metadata.PropertyName + "_";
        if (depProp.StartsWith(thisField))
            // strip it off again
            depProp = depProp.Substring(thisField.Length);
        return depProp;
    }
}