asp.net-mvc 从控制器手动设置 ModelState.isValid
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Manually Set ModelState.isValid from Controller
提问by Chase Florell
Is there a way for me to manually set the ModelState.isValid = Falsefrom the controller?
有没有办法让我ModelState.isValid = False从控制器手动设置？
I have some code like this
我有一些这样的代码
Dim _region As Domain.Region = RegionService.GetRegionByNameAndParentID(user.UserRegion, user.ParentRegionID)
If ModelState.IsValid AndAlso Not _region Is Nothing Then
''# ...
Else
Return View(user)
End If
But if _region is nothing, then I don't get any Validation Errors firing.
但是如果 _region 什么都不是，那么我不会触发任何验证错误。
I thought about implementing a custom validator, but it would require hitting the database twice (once for validation and once to set the value).
我考虑过实现自定义验证器，但它需要两次访问数据库（一次用于验证，一次用于设置值）。
回答by richeym
You can't set ModelState.IsValiddirectly, as it's a derived property that simply checks the models error collection. You can however add your own model errors, e.g:
您不能ModelState.IsValid直接设置，因为它是一个派生属性，它只是检查模型错误集合。但是，您可以添加自己的模型错误，例如：
ModelState.AddModelError("Region", "Region is mandatory");
ModelState.IsValidwill then return false.
ModelState.IsValid然后将返回false。
