How to visually indicate current page in ASP.NET MVC?

问题

As a base for discussion. Create a standard ASP.NET MVC Web project.

It will contain two menu items in the master page:

<div id="menucontainer">
  <ul id="menu">
    <li>
      <%= Html.ActionLink("Home", "Index", "Home")%></li>
    <li>
      <%= Html.ActionLink("About", "About", "Home")%></li>
  </ul>
</div>

How can I set the visual CSS style indicating the current page. For example, when in the About page/controller, I essentially would like to do this:

<%= Html.ActionLink("About", "About", "Home", new {class="current"})%></li>

And, of course, when on the home page:

<%= Html.ActionLink("Home", "Index", "Home", new {class="current"})%></li>

(Having a CSS style names current that visually indicates in the menu that this is the current page.)

I could break out the menu div from the master page into a content place holder, but that would mean that I must put the menu on every page.

Any ideas, is there a nice solution to this?

回答1:

The easiest way is to get the current controller and action from the ViewContext's RouteData. Note the change in signature and use of @ to escape the keyword.

<% var controller = ViewContext.RouteData.Values["controller"] as string ?? "Home";
   var action = ViewContext.RouteData.Values["action"] as string ?? "Index";
   var page = (controller + ":" + action).ToLower();
 %>

<%= Html.ActionLink( "About", "About", "Home", null,
                     new { @class = page == "home:about" ? "current" : "" ) %>
<%= Html.ActionLink( "Home", "Index", "Home", null,
                     new { @class = page == "home:index" ? "current" : "" ) %>

Note that you could combine this an HtmlHelper extension like @Jon's and make it cleaner.

<%= Html.MenuLink( "About", "About", "Home", null, null, "current" ) %>

Where MenuActionLink is

public static class MenuHelperExtensions
{
     public static string MenuLink( this HtmlHelper helper,
                                    string text,
                                    string action,
                                    string controller,
                                    object routeValues,
                                    object htmlAttributes,
                                    string currentClass )
     {
         RouteValueDictionary attributes = new RouteValueDictionary( htmlAttributes );
         string currentController = helper.ViewContext.RouteData.Values["controller"] as string ?? "home";
         string currentAction = helper.ViewContext.RouteData.Values["action"] as string ?? "index";
         string page = string.Format( "{0}:{1}", currentController, currentAction ).ToLower();
         string thisPage = string.Format( "{0}:{1}", controller, action ).ToLower();
         attributes["class"] = (page == thisPage) ? currentClass : "";
        return helper.ActionLink( text, action, controller, new RouteValueDictionary( routeValues ), attributes );
     }
}

回答2:

I recently created an HTML Helper for this that looks like:

public static string NavigationLink(this HtmlHelper helper, string path, string text)
{
    string cssClass = String.Empty;
    if (HttpContext.Current.Request.Path.IndexOf(path) != -1)
    {
        cssClass = "class = 'selected'";
    }

    return String.Format(@"<li><a href='{0}' {1}>{2}</a></li>", path, cssClass, text);
}

The Implementation looks like this:

  <ul id="Navigation">
  <%=Html.NavigationLink("/Path1", "Text1")%>
  <%=Html.NavigationLink("/Path2", "Text2")%>
  <%=Html.NavigationLink("/Path3", "Text3")%>
  <%=Html.NavigationLink("/Path4", "Text4")%>
  </ul>

回答3:

If you are using T4MVC, you can use this:

        public static HtmlString MenuLink(
        this HtmlHelper helper,
        string text,
        IT4MVCActionResult action,
        object htmlAttributes = null)
    {
        var currentController = helper.ViewContext.RouteData.Values["controller"] as string ?? "home";
        var currentAction = helper.ViewContext.RouteData.Values["action"] as string ?? "index";

        var attributes = new RouteValueDictionary(htmlAttributes);
        var cssClass = (attributes.ContainsKey("class"))
                           ? attributes["class"] + " "
                           : string.Empty;

        string selectedClass;
        if(action.Controller.Equals(currentController, StringComparison.InvariantCultureIgnoreCase)
        {
            selectedClass = "selected-parent";
            if(action.Action.Equals(currentAction, StringComparison.InvariantCultureIgnoreCase))
                selectedClass = "selected";
        }
        cssClass += selectedClass;

        attributes["class"] = cssClass;

        return helper.ActionLink(text, (ActionResult)action, attributes);
    }

回答4:

It might just be that it's the 5th parameter, so slot a null before your html attribute. This post here describes it as such, though you can pass in some stuff on the 4th arguement, the 5th is specifically for HTMLattributes

回答5:

<script type="javascript/text">
$( document ).ready( function() {

        @if (Request.Url.AbsolutePath.ToLower() == "/") 
        {
            @Html.Raw("$('.navbar-nav li').eq(0).attr('class','active');")
        }

        @if (Request.Url.AbsolutePath.ToLower().Contains("details")) 
        {
            @Html.Raw("$('.navbar-nav li').eq(1).attr('class','active');")
        }

        @if (Request.Url.AbsolutePath.ToLower().Contains("schedule")) 
        {
            @Html.Raw("$('.navbar-nav li').eq(2).attr('class','active');")
        }

    });
</script>

Chucked this together in 5mins, I could probably refactor it, but should give you the basic idea, its probably most useful for smaller sites.

来源：https://stackoverflow.com/questions/1471362/how-to-visually-indicate-current-page-in-asp-net-mvc

标签

css

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