给定以下viewmodel：
public class Someviewmodel { public bool IsA { get; set; } public bool IsB { get; set; } public bool IsC { get; set; } //... other properties }
我希望创建一个自定义属性，验证至少一个可用属性为true。我想象能够附加一个属性到一个属性，并像这样分配一个组名：
public class Someviewmodel { [RequireAtLeastOneOfGroup("Group1")] public bool IsA { get; set; } [RequireAtLeastOneOfGroup("Group1")] public bool IsB { get; set; } [RequireAtLeastOneOfGroup("Group1")] public bool IsC { get; set; } //... other properties [RequireAtLeastOneOfGroup("Group2")] public bool IsY { get; set; } [RequireAtLeastOneOfGroup("Group2")] public bool IsZ { get; set; } }
我想在客户端验证在表单提交之前作为表单更改的值，这就是为什么我喜欢避免类级属性(如果可能的话)。
这需要服务器端验证和客户端验证，以定位所有具有相同组名称值的属性作为自定义属性的参数传入。这可能吗？任何指导是非常赞赏。
解决方法
这里有一种方法继续(还有其他方法，我只是说明一个将匹配您的视图模型是)：
[AttributeUsage(AttributeTargets.Property)]
public class RequireAtLeastOneOfGroupAttribute: ValidationAttribute,IClientValidatable
{
public RequireAtLeastOneOfGroupAttribute(string groupName)
{
ErrorMessage = string.Format("You must select at least one value from group \"{0}\"",groupName);
GroupName = groupName;
}
public string GroupName { get; private set; }
protected override ValidationResult IsValid(object value,ValidationContext validationContext)
{
foreach (var property in GetGroupProperties(validationContext.ObjectType))
{
var propertyValue = (bool)property.GetValue(validationContext.ObjectInstance,null);
if (propertyValue)
{
// at least one property is true in this group => the model is valid
return null;
}
}
return new ValidationResult(FormatErrorMessage(validationContext.DisplayName));
}
private IEnumerable<PropertyInfo> GetGroupProperties(Type type)
{
return
from property in type.GetProperties()
where property.PropertyType == typeof(bool)
let attributes = property.GetCustomAttributes(typeof(RequireAtLeastOneOfGroupAttribute),false).OfType<RequireAtLeastOneOfGroupAttribute>()
where attributes.Count() > 0
from attribute in attributes
where attribute.GroupName == GroupName
select property;
}
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata Metadata,ControllerContext context)
{
var groupProperties = GetGroupProperties(Metadata.ContainerType).Select(p => p.Name);
var rule = new ModelClientValidationRule
{
ErrorMessage = this.ErrorMessage
};
rule.ValidationType = string.Format("group",GroupName.ToLower());
rule.ValidationParameters["propertynames"] = string.Join(",",groupProperties);
yield return rule;
}
}
现在，让我们定义一个控制器：
public class HomeController : Controller
{
public ActionResult Index()
{
var model = new Someviewmodel();
return View(model);
}
[HttpPost]
public ActionResult Index(Someviewmodel model)
{
return View(model);
}
}
和一个视图：
@model Someviewmodel <script src="@Url.Content("~/Scripts/jquery.validate.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.js")" type="text/javascript"></script> @using (Html.BeginForm()) { @Html.EditorFor(x => x.IsA) @Html.ValidationMessageFor(x => x.IsA) <br/> @Html.EditorFor(x => x.IsB)<br/> @Html.EditorFor(x => x.IsC)<br/> @Html.EditorFor(x => x.IsY) @Html.ValidationMessageFor(x => x.IsY) <br/> @Html.EditorFor(x => x.IsZ)<br/> <input type="submit" value="OK" /> }
剩下的最后一部分是注册适配器以进行客户端验证：
jQuery.validator.unobtrusive.adapters.add(
'group',[ 'propertynames' ],function (options) {
options.rules['group'] = options.params;
options.messages['group'] = options.message;
}
);
jQuery.validator.addMethod('group',function (value,element,params) {
var properties = params.propertynames.split(',');
var isValid = false;
for (var i = 0; i < properties.length; i++) {
var property = properties[i];
if ($('#' + property).is(':checked')) {
isValid = true;
break;
}
}
return isValid;
},'');
根据您的具体要求，代码可能会进行调整。
