Get the selected drop down list value from a FormCollection in MVC

问题

I have a form posting to an action with MVC. I want to pull the selected drop down list item from the FormCollection in the action. How do I do it?

My Html form:

<% using (Html.BeginForm())
    {%>
    <select name="Content List">
    <% foreach (String name in (ViewData["names"] as IQueryable<String>)) { %>
          <option value="<%= name %>"><%= name%></option>
    <% } %>
    </select>
    <p><input type="submit" value="Save" /></p>
<% } %>

My Action:

[HttpPost]
public ActionResult Index(FormCollection collection)
{
    //how do I get the selected drop down list value?
    String name = collection.AllKeys.Single();
    return RedirectToAction("Details", name);
}

回答1:

Start by giving your select tag a valid name. A valid name cannot contain spaces.

<select name="contentList">

and then fetch the selected value from the form parameters collection:

var value = collection["contentList"];

Or even better: don't use any collections, use an action parameter which has the same name as the name of your select and leave the default model binder populate it:

[HttpPost]
public ActionResult Index(string contentList)
{
    // contentList will contain the selected value
    return RedirectToAction("Details", contentList);
}

来源：https://stackoverflow.com/questions/3004788/get-the-selected-drop-down-list-value-from-a-formcollection-in-mvc