问题
I was working on migrating MVC1 app to MVC2 today and i have come across a problem while changing the ValidationMessage to ValidationMessageFor implementation.
The below is the selectlist in my View
<%=Html.DropDownListFor(model => model.SecurityQuestions[0].Question, "Some Security question", new { @class = "form_element_select" })%>
The below code works fine and i can see the validation message came from modelstate.
<%= Html.ValidationMessage("SecurityQuestions_0__Question")%>
but this one does not work:
<%= Html.ValidationMessageFor(model => model.SecurityQuestions[0].Question)%>
SecurityQuestions is a generic list in my model
public List<SecurityQuestion> SecurityQuestions { get; set; }
Is this somewhat a bug in "ValidationMessageFor" or am i missing something here?
I have previously asked this question on asp.net forums.
回答1:
The problem is that ValidationMessageFor only uses the last property name as validation message key.
In your case this means that:
<%= Html.ValidationMessageFor(model => model.SecurityQuestions[0].Question) %>
equals
<%= Html.ValidationMessage("Question") %>
and not what you thought it would. Unfortunately in this case you will have to use the non-strong typed helper to have the whole string as it should be.
回答2:
This problem is fixed in MVC V3
回答3:
You can add error you want to see to ModelState, under key that is generated by ValidationMessageFor. Sure its a hack, but the fastest way to go. And it doesnt add any ugly "SecurityQuestions_0__Question" to your markup.
来源：https://stackoverflow.com/questions/2681159/implementing-validationmessagefor