在ASP.NET MVC 1.0中使用ModelBinder处理无效值(Handling invalid values with ModelBinder in ASP.NET MVC 1.0)

 首先是一些背景 ： 
 
 我有一个表单，在那里我发布了一些由MVC内置的ModelBinder自动实现对象的对象： 
 
<input type="hidden" name="myobj[0].Id" />
<input type="text" name="myobj[0].Hours" />
<input type="hidden" name="myobj[1].Id" />
<input type="text" name="myobj[1].Hours" />

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Save(IList<MyObject> myobj);
 
 另外：我想强调的是，我们正在向DTO（DataTransferObjects）发布我们进一步沿着线图映射到实体框架实体，所以我们宁愿不喜欢DTO上的任何更改，除非可能添加属性。 
 
 问题 
 
 如果用户为“小时”输入无效值，例如“Fubar”，则ModelBinder自然不会尝试设置“小时”属性。 但它默认为0，因为它是一个int而不是一个字符串 。 
 
 这对我来说会造成一些困难，因为现在我无法看到用户是否实际输入了0，或者这是否是由无效输入引起的。 
 
 由于我使用的是自制的对象到实体（Entity Framework）映射器，我们无法将'Hours'属性的脚印更改为int？ 。 我知道MVC有一些内置的验证，但我们宁愿不实现它，因为我们知道它已经受到了极大的攻击，并且ASP.NET MVC 2.0中还有一些新的验证。 
 
 解？ 
 
 我需要能够向用户指出哪个字段不正确，这意味着我需要能够捕获异常（或者可能是其他一些巧妙的解决方案？），在那里我可以做一些逻辑并回发一个新的查看用户我澄清他们做错了什么。 
 
 我目前的想法：编写自定义ModelBinder。 
 
 你有什么建议？ 

First of all some context:
 
I have a form, where I post back some objects that are automatically materialized into objects by MVCs built-in ModelBinder:
 
<input type="hidden" name="myobj[0].Id" />
<input type="text" name="myobj[0].Hours" />
<input type="hidden" name="myobj[1].Id" />
<input type="text" name="myobj[1].Hours" />

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Save(IList<MyObject> myobj);
 
Additionally: I would like to stress that we are posting to DTO (DataTransferObjects) that we further down the line map into entity framework entities, so we would rather not like the change anything on the DTO's except maybe adding attributes.
 
Problem
 
If a user enters an invalid value for "Hours", say 'Fubar', then the ModelBinder naturally will not attempt to set the 'Hours'-property. But it defaults to 0, because it is an int and not a string.
 
This causes some difficulty for me ofcourse, because now I can't see if the user actually entered 0, or if this was caused by invalid input.
 
Since I am using a home-rolled object-to-entity (Entity Framework) mapper, we cannot change the foot-print of the 'Hours'-property to int?. I am aware that MVC has some built in Validation, but we would rather not implement that since we know it has been wildly attacked and that there is some new validation coming in ASP.NET MVC 2.0.
 
Solution?
 
I need to be able to point out to the user which field is incorrect, so that means I somehow need to be able to catch an exception (or possibly some other ingenious solution?), where I can do some logic and post back a new view to the user where I clarify what they did incorrectly.
 
My current idea: Writing a custom ModelBinder.
 
What do you suggest?

原文：https://stackoverflow.com/questions/2134100