如果设备在asp.net web form app中移动,则更改母版页

当你创建一个新的asp.net项目我nvisual studio 2012时,它会用这段代码添加一个ascx：`//确定当前视图
????????????var isMobile = WebFormsFriendlyUrlResolver.IsMobileView(new HttpContextWrapper(Context));
????????????CurrentView = isMobile？ “手机”：“桌面”;

// Determine alternate view
        AlternateView = isMobile ? "Desktop" : "Mobile";

        // Create switch URL from the route,e.g. ~/__FriendlyUrls_SwitchView/Mobile?ReturnUrl=/Page
        var switchViewRouteName = "AspNet.FriendlyUrls.SwitchView";
        var switchViewRoute = RouteTable.Routes[switchViewRouteName];
        if (switchViewRoute == null)
        {
            // Friendly URLs is not enabled or the name of the swith view route is out of sync
            this.Visible = false;
            return;
        }
        var url = GetRouteUrl(switchViewRouteName,new { view = AlternateView });
        url += "?ReturnUrl=" + HttpUtility.UrlEncode(Request.RawUrl);
        SwitchUrl = url;`

我真的不理解它,它是如何工作的？这个奇怪的代码是什么？WebFormsFriendlyUrlResolver？我有一个现有的项目,我想知道如果检测到移动浏览器是否可以切换母版页

void page_PreInit(object sender,EventArgs e)
    {
        Page p = this.Context.Handler as Page;
        if (p != null)
        {
            // set master page
            if(Request.Browser.IsMobileDevice){
              p.MasterPageFile = "~/MasterPages/mobile.master";
            }
            else{
               p.MasterPageFile = "~/MasterPages/normal.master";
            }

        }
    }