7

我想强制我系统中的所有日期都是有效的,而不是将来,所以我在自定义模型绑定器中强制它们:

class DateTimeModelBinder : IModelBinder {
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) {
        var value = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
        try {
            var date = value.ConvertTo(typeof(DateTime), CultureInfo.CurrentCulture);

            // Here I want to ask first if the property has the FutureDateAttribute
            if ((DateTime)date > DateTime.Today) {
                bindingContext.ModelState.AddModelError(bindingContext.ModelName, "No se puede indicar una fecha mayor a hoy");
            }

            return date;
        }
        catch (Exception) {
            bindingContext.ModelState.AddModelError(bindingContext.ModelName, "La fecha no es correcta");
            return value.AttemptedValue;
        }
    }

}

现在,对于一些例外情况,我想允许一些日期在未来

    [Required]
    [Display(Name = "Future Date")]
    [DataType(DataType.DateTime)]
    [FutureDateTime] <-- this attribute should allow the exception
    public DateTime FutureFecha { get; set; }

这是属性

[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
public class FutureDateTimeAttribute : Attribute {

}

现在,问题是:如何检查该属性是否存在于BindModel方法中?

4

1 回答 1

17

在绑定模型属性期间,我们可以通过以下方式访问属性所有者:

bindingContext.ModelMetadata.ContainerType.

因此,下面的代码片段应该为您将FutureFecha属性的变量hasAttribute设置为 true

var holderType = bindingContext.ModelMetadata.ContainerType;
if (holderType != null)
{
  var propertyType = holderType.GetProperty(bindingContext.ModelMetadata.PropertyName);
  var attributes = propertyType.GetCustomAttributes(true);
  var hasAttribute = attributes
    .Cast<Attribute>()
    .Any(a => a.GetType().IsEquivalentTo(typeof (FutureDateTime)));
  if(hasAttribute) ...
}
于 2012-12-14T13:21:17.283 回答