如何在 ASP.NET MVC 中直观地指示当前页面? [英] How to visually indicate current page in ASP.NET MVC?

问题描述

作为讨论的基础.创建一个标准的 ASP.NET MVC Web 项目.

它将在母版页中包含两个菜单项:

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

如何设置指示当前页面的可视化 CSS 样式.例如，当在关于页面/控制器中时，我基本上想这样做:

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

当然，在主页上时:

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

(有一个 CSS 样式名称 current，在菜单中直观地表明这是当前页面.)

我可以将母版页中的菜单 div 拆分为内容占位符，但这意味着我必须将菜单放在每个页面上.

任何想法，有没有好的解决方案?

解决方案

最简单的方法是从 ViewContext 的 RouteData 中获取当前控制器和操作.请注意签名的变化和使用@ 来转义关键字.

<% var controller = ViewContext.RouteData.Values["controller"] as string ??家";var action = ViewContext.RouteData.Values["action"] 作为字符串 ??指数";var page = (controller + ":" + action).ToLower();％＞<%= Html.ActionLink( "关于", "关于", "首页", null,new { @class = page == "home:about" ?当前":")%><%= Html.ActionLink( "Home", "Index", "Home", null,new { @class = page == "home:index" ?当前":")%>

请注意，您可以将它与@Jon 的 HtmlHelper 扩展程序结合起来，使其更简洁.

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

MenuActionLink 在哪里

公共静态类 MenuHelperExtensions{公共静态字符串 MenuLink(这个 HtmlHelper 助手，字符串文本，字符串动作，字符串控制器，对象路由值，对象 htmlAttributes，字符串 currentClass ){RouteValueDictionary 属性 = 新的 RouteValueDictionary( htmlAttributes );string currentController = helper.ViewContext.RouteData.Values["controller"] as string ??家";字符串 currentAction = helper.ViewContext.RouteData.Values["action"] 作为字符串 ??指数";string page = string.Format( "{0}:{1}", currentController, currentAction ).ToLower();string thisPage = string.Format( "{0}:{1}", controller, action ).ToLower();属性["class"] = (page == thisPage) ?当前类:"；return helper.ActionLink( text, action, controller, new RouteValueDictionary( routeValues ), attributes );}}

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?

解决方案

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 );
     }
}

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