Value set in the hidden field is not reflecting in document ready function

问题

I am not able to retrieve the values from hidden field. Sometimes I am getting values & sometimes its coming empty. Please assist.

Also let me know can we store a C# arraylist in a hiddenfield? My HTML looks like this...

<input type="hidden" id="hdnSelectedContactID" value="@Model.Contact.ContactID" />
<input type="hidden" id="hdnSelectedAddressList" value="@Model.Contact.AddressList" />


$(document).ready(function () {
        _contactID = $("#hdnSelectedContactID").val();
        _addressList = $("#hdnSelectedAddressList").val();
}

After assigning a name to it in document.ready method, the outer html(in quick watch) appears like this...

outerHTML         "<INPUT id=hdnSelectedContactID type=hidden name=hdnSelectedContactID>"            String

outerHTML         "<INPUT id=hdnSelectedAddressList value=Dell.USP.Business.Models.TelephoneList type=hidden name=hdnSelectedAddressList>"       String

回答1:

Why not use a helper to insert a hidden field?

@Html.HiddenFor(h => h.ContactID)

You can't store an arraylist in a hiddenfield as an object, but you can insert the values of an arraylist in a hiddenfield with delimiters to seperate them. You turn it into a string and load it in the view.

回答2:

Addition: initialization of js-variable with ArrayList:

<script type="text/javascript">

    var _addressList = @Html.Raw(string.Format("['{0}']", string.Join("','", Model.Contact.AddressList.ToArray().Select(s => HttpUtility.HtmlEncode(s.ToString())))));

    $(document).ready(function () {

        // test 
        alert(_addressList[0]);
    });

</script>

回答3:

As an extra note you CAN serialize your list into a hidden field using the MVCContrib Html.Serialize function. However this is basically for server side reuse again similar to viewstate

回答4:

First of all in MVC 3.0, always try to use its own controls from HTML helpers, like @Html.HiddenFor(c => c.Contact.Title), instead of

<input type="hidden" id="hdnSelectedContactID" value="@Model.Contact.ContactID" />

Also I came to the conclusion that if there is another control with same lamda expression (For example my contactID & hidden contactID control both has the same h => h.ContactID expression), I ve to add an extra "id" attribute, as @Html.HiddenFor(h => h.Contact.Title, new { id = "hdnContactID" } ). Else wrong value might get overridden.

来源：https://stackoverflow.com/questions/7130383/value-set-in-the-hidden-field-is-not-reflecting-in-document-ready-function