Asp.net mvc 4 MVC RequiredIf属性-IsValid值参数始终为空
我正在实现一个RequiredIf验证属性,传递给IsValid方法的值始终为null 要求属性类Asp.net mvc 4 MVC RequiredIf属性-IsValid值参数始终为空,asp.net-mvc-4,data-annotations,validationattribute,Asp.net Mvc 4,Data Annotations,Validationattribute,我正在实现一个RequiredIf验证属性,传递给IsValid方法的值始终为null 要求属性类 public class RequiredIfAttribute : ValidationAttribute { private RequiredAttribute innerAttribute = new RequiredAttribute(); public string DependentProperty { get; set; } public object
public class RequiredIfAttribute : ValidationAttribute
{
private RequiredAttribute innerAttribute = new RequiredAttribute();
public string DependentProperty { get; set; }
public object TargetValue { get; set; }
public RequiredIfAttribute(string dependentProperty, object targetValue)
{
this.DependentProperty = dependentProperty;
this.TargetValue = targetValue;
}
public override bool IsValid(object value)
{
return innerAttribute.IsValid(value);
}
}
视图模型
[Required]
[Display(Name = "Are You A Student?")]
public bool? IsStudent { get; set; }
[RequiredIf("IsStudent", true, ErrorMessage = "You must upload a photo of your student ID if you wish to register as a student.")]
[Display(Name = "Student ID")]
[FileExtensions("jpg|jpeg|png|pdf", ErrorMessage = "File is not in the correct format.")]
[MaxFileSize(2 * 1024 * 1024, ErrorMessage = "You may not upload files larger than 2 MB.")]
public HttpPostedFileBase StudentId { get; set; }
编辑模板
@model bool?
@using System.Web.Mvc;
@{
var options = new List<SelectListItem>
{
new SelectListItem { Text = "Yes", Value = "true", Selected = Model.HasValue && Model.Value },
new SelectListItem { Text = "No", Value = "false", Selected = Model.HasValue && Model.Value }
};
string defaultOption = null;
if (ViewData.ModelMetadata.IsNullableValueType)
{
defaultOption = "(Select)";
}
}
@Html.DropDownListFor(m => m, options, defaultOption)
每次提交表单时,都会抛出RequiredIf错误消息,我感觉这与我最初描述的空值有关。我做错了什么?谢谢
注意:HTML似乎呈现正确,所以我认为这不是问题所在
<select data-val="true" data-val-required="The Are You A Student? field is required." id="IsStudent" name="IsStudent"><option value="">(Select)</option>
<option value="true">Yes</option>
<option value="false">No</option>
</select>
因为这是你的密码-
public class RequiredIfAttribute : ValidationAttribute
{
private RequiredAttribute innerAttribute = new RequiredAttribute();
public string DependentProperty { get; set; }
public object TargetValue { get; set; }
public RequiredIfAttribute(string dependentProperty, object targetValue)
{
this.DependentProperty = dependentProperty;
this.TargetValue = targetValue;
}
public override bool IsValid(object value)
{
return innerAttribute.IsValid(value);
}
}
您正在使用RequiredAttribute。因此,为了模拟它的行为,如果你必须实现一些逻辑来检查目标属性值是真是假。但您并没有这样做,只是从innerattribute返回。因此,这只是一个要求,而不是要求-
修改此函数以执行一些检查,如-
public override bool IsValid(object value)
{
//if the referred property is true then
return innerAttribute.IsValid(value);
//else
return True
}
我使用以下代码:
[AttributeUsage(AttributeTargets.Property, AllowMultiple = true)]
public abstract class StefAttribute : ValidationAttribute
{
public WDCIAttribute()
: base()
{
this.ErrorMessageResourceType = typeof(GlobalResources);
}
}
[AttributeUsage(AttributeTargets.Property, AllowMultiple = true, Inherited = true)]
public class StefRequiredIfAttribute : StefAttribute
{
private RequiredAttribute innerAttribute = new RequiredAttribute();
public string DependentProperty { get; set; }
public object TargetValue { get; set; }
public WDCIRequiredIfAttribute()
{
}
public WDCIRequiredIfAttribute(string dependentProperty, object targetValue)
: base()
{
this.DependentProperty = dependentProperty;
this.TargetValue = targetValue;
}
public override bool IsValid(object value)
{
return innerAttribute.IsValid(value);
}
}
public class RequiredIfValidator : DataAnnotationsModelValidator<StefRequiredIfAttribute>
{
public RequiredIfValidator(ModelMetadata metadata, ControllerContext context, StefRequiredIfAttribute attribute)
: base(metadata, context, attribute)
{
}
public override IEnumerable<ModelValidationResult> Validate(object container)
{
// get a reference to the property this validation depends upon
var field = Metadata.ContainerType.GetProperty(Attribute.DependentProperty);
if (field != null)
{
// get the value of the dependent property
object value = field.GetValue(container, null);
// compare the value against the target value
if (IsEqual(value) || (value == null && Attribute.TargetValue == null))
{
// match => means we should try validating this field
if (!Attribute.IsValid(Metadata.Model))
{
// validation failed - return an error
yield return new ModelValidationResult { Message = ErrorMessage };
}
}
}
}
private bool IsEqual(object dependentPropertyValue)
{
bool isEqual = false;
if (Attribute.TargetValue != null && Attribute.TargetValue.GetType().IsArray)
{
foreach (object o in (Array)Attribute.TargetValue)
{
isEqual = o.Equals(dependentPropertyValue);
if (isEqual)
{
break;
}
}
}
else
{
if (Attribute.TargetValue != null)
{
isEqual = Attribute.TargetValue.Equals(dependentPropertyValue);
}
}
return isEqual;
}
}
我不打算用这个实现客户端验证,我们的服务器端验证属性也有一个非常类似的实现。我感谢你的发帖,但我在这里没有看到解决方案。谢谢,但我的代码与其他字段一样工作,所以我认为你用这个解决方案找错了方向。这似乎与以下事实有关:该字段可以为空,或者它可以为空,并且使用下拉菜单作为选择机制。@domroco您选错了树。无脑编码器是100%正确的。
[AttributeUsage(AttributeTargets.Property, AllowMultiple = true)]
public abstract class StefAttribute : ValidationAttribute
{
public WDCIAttribute()
: base()
{
this.ErrorMessageResourceType = typeof(GlobalResources);
}
}
[AttributeUsage(AttributeTargets.Property, AllowMultiple = true, Inherited = true)]
public class StefRequiredIfAttribute : StefAttribute
{
private RequiredAttribute innerAttribute = new RequiredAttribute();
public string DependentProperty { get; set; }
public object TargetValue { get; set; }
public WDCIRequiredIfAttribute()
{
}
public WDCIRequiredIfAttribute(string dependentProperty, object targetValue)
: base()
{
this.DependentProperty = dependentProperty;
this.TargetValue = targetValue;
}
public override bool IsValid(object value)
{
return innerAttribute.IsValid(value);
}
}
public class RequiredIfValidator : DataAnnotationsModelValidator<StefRequiredIfAttribute>
{
public RequiredIfValidator(ModelMetadata metadata, ControllerContext context, StefRequiredIfAttribute attribute)
: base(metadata, context, attribute)
{
}
public override IEnumerable<ModelValidationResult> Validate(object container)
{
// get a reference to the property this validation depends upon
var field = Metadata.ContainerType.GetProperty(Attribute.DependentProperty);
if (field != null)
{
// get the value of the dependent property
object value = field.GetValue(container, null);
// compare the value against the target value
if (IsEqual(value) || (value == null && Attribute.TargetValue == null))
{
// match => means we should try validating this field
if (!Attribute.IsValid(Metadata.Model))
{
// validation failed - return an error
yield return new ModelValidationResult { Message = ErrorMessage };
}
}
}
}
private bool IsEqual(object dependentPropertyValue)
{
bool isEqual = false;
if (Attribute.TargetValue != null && Attribute.TargetValue.GetType().IsArray)
{
foreach (object o in (Array)Attribute.TargetValue)
{
isEqual = o.Equals(dependentPropertyValue);
if (isEqual)
{
break;
}
}
}
else
{
if (Attribute.TargetValue != null)
{
isEqual = Attribute.TargetValue.Equals(dependentPropertyValue);
}
}
return isEqual;
}
}
public class PersonnelVM : EntityVM
{
// . . .
[DisplayName("Name")]
[StefRequiredIf("IndividualOrBulk", PersonnelType.Bulk, ErrorMessageResourceName = GlobalResourceLiterals.Name_Required)]
public string Name { get; set; }
[DisplayName("PersonnelType")]
public PersonnelType IndividualOrBulk { get; set; }
// . . .
}