??? 在ASP.NET MVC中來實(shí)現(xiàn)主題的切換一般有兩種方式，一種是通過切換皮膚的css和js引用，一種就是通過重寫視圖引擎。通過重寫視圖引擎的方式更加靈活，因?yàn)槲也粌H可以在不同主題下面布局和樣式不一樣，還可以讓不同的主題下面顯示的數(shù)據(jù)條目不一致，就是說可以在某些主題下面添加一下個(gè)性化的東西。

??? 本篇我將通過重寫視圖引擎的方式來進(jìn)行演示，在這之前，我假設(shè)你已經(jīng)具備了MVC的一些基礎(chǔ)，系統(tǒng)登錄后是默認(rèn)主題，當(dāng)我們點(diǎn)擊切換主題之后，左側(cè)菜單欄的布局變了，右側(cè)內(nèi)容的樣式也變了，而地址欄是不變的。界面UI用的metronic，雖然官網(wǎng)是收費(fèi)的，但是在天朝，總是可以找到免費(fèi)的。metronic是基于bootstrap的UI框架，官網(wǎng)地址：http://keenthemes.com/preview/metronic/

??? 我們先來看下效果：

??? 在這里，我使用了分區(qū)域、分模塊（按獨(dú)立的業(yè)務(wù)功能劃分）的方式，一個(gè)模塊就是一個(gè)獨(dú)立的dll，在這里Secom.Emx.Admin和Secom.Emx.History就是兩個(gè)獨(dú)立的模塊，并分別創(chuàng)建了區(qū)域Admin和History，當(dāng)然你可以在獨(dú)立模塊下面創(chuàng)建多個(gè)區(qū)域。

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??? 你會(huì)發(fā)現(xiàn)Secom.Emx.Admin模型下面的Areas目錄和Secom.Emx.WebApp中的目錄是一模一樣的，其實(shí)我最初不想在模塊項(xiàng)目中添加任何的View，但是為了方便獨(dú)立部署還是加了。右鍵單擊項(xiàng)目Secom.Emx.Admin，選擇“屬性”——“生成事件”添加如下代碼：

xcopy /e/r/y $(ProjectDir)Areas\Admin\Views $(SolutionDir)Secom.Emx.WebApp\Areas\Admin\Views

??? 這命令很簡(jiǎn)單，其實(shí)就是當(dāng)編譯項(xiàng)目Secom.Emx.Admin的時(shí)候，將項(xiàng)目中的Views復(fù)制到Secom.Emx.WebApp項(xiàng)目的指定目錄下。

??? 區(qū)域配置文件我放置到了Secom.Emx.WebApp中，其實(shí)你完全可以獨(dú)立放置到一個(gè)類庫(kù)項(xiàng)目中，因?yàn)樽?cè)區(qū)域路由的后，項(xiàng)目最終會(huì)尋找bin目錄下面所有繼承了AreaRegistration類的，然后讓W(xué)ebApp引用這個(gè)類庫(kù)項(xiàng)目，Secom.Emx.WebApp項(xiàng)目添加Secom.Emx.Admin、Secom.Emx.History的引用。

??? AdminAreaRegistration代碼如下：

using System.Web.Mvc;namespace Secom.Emx.WebApp {public class AdminAreaRegistration : AreaRegistration {public override string AreaName {get {return "Admin";}}public override void RegisterArea(AreaRegistrationContext context) {context.MapRoute("Admin_default","Admin/{controller}/{action}/{id}",new { action = "Index", id = UrlParameter.Optional },namespaces:new string[1] { "Secom.Emx.Admin.Areas.Admin.Controllers" });}} }

??? 注意命名空間和后面添加的 namespaces:new string[1] { "Secom.Emx.Admin.Areas.Admin.Controllers" }，這個(gè)命名空間就是獨(dú)立模塊Secom.Emx.Admin下面的控制器所在的命名空間。HistoryAreaRegistration代碼如下：

using System.Web.Mvc;namespace Secom.Emx.WebApp {public class HistoryAreaRegistration : AreaRegistration {public override string AreaName {get {return "History";}}public override void RegisterArea(AreaRegistrationContext context) {context.MapRoute("History_default","History/{controller}/{action}/{id}",new { action = "Index", id = UrlParameter.Optional },namespaces:new string[1] { "Secom.Emx.History.Areas.History.Controllers" });}} } View Code

??? 我們先看下RazorViewEngine的原始構(gòu)造函數(shù)如下：

public RazorViewEngine(IViewPageActivator viewPageActivator) : base(viewPageActivator) { AreaViewLocationFormats = new[] { "~/Areas/{2}/Views/{1}/{0}.cshtml", "~/Areas/{2}/Views/{1}/{0}.vbhtml", "~/Areas/{2}/Views/Shared/{0}.cshtml", "~/Areas/{2}/Views/Shared/{0}.vbhtml" }; AreaMasterLocationFormats = new[] { "~/Areas/{2}/Views/{1}/{0}.cshtml", "~/Areas/{2}/Views/{1}/{0}.vbhtml", "~/Areas/{2}/Views/Shared/{0}.cshtml", "~/Areas/{2}/Views/Shared/{0}.vbhtml" }; AreaPartialViewLocationFormats = new[] { "~/Areas/{2}/Views/{1}/{0}.cshtml", "~/Areas/{2}/Views/{1}/{0}.vbhtml", "~/Areas/{2}/Views/Shared/{0}.cshtml", "~/Areas/{2}/Views/Shared/{0}.vbhtml" }; ViewLocationFormats = new[] { "~/Views/{1}/{0}.cshtml", "~/Views/{1}/{0}.vbhtml", "~/Views/Shared/{0}.cshtml", "~/Views/Shared/{0}.vbhtml" }; MasterLocationFormats = new[] { "~/Views/{1}/{0}.cshtml", "~/Views/{1}/{0}.vbhtml", "~/Views/Shared/{0}.cshtml", "~/Views/Shared/{0}.vbhtml" }; PartialViewLocationFormats = new[] { "~/Views/{1}/{0}.cshtml", "~/Views/{1}/{0}.vbhtml", "~/Views/Shared/{0}.cshtml", "~/Views/Shared/{0}.vbhtml" }; FileExtensions = new[] { "cshtml", "vbhtml", }; } View Code

??? 然后新建CustomRazorViewEngine繼承自RazorViewEngine，對(duì)View的路由規(guī)則進(jìn)行了重寫，既然可以重寫路由規(guī)則，那意味著，你可以任意定義規(guī)則，然后遵守自己定義的規(guī)則就可以了。需要注意的是，要注意路由數(shù)組中的順序，查找視圖時(shí)，是按照前后順序依次查找的，當(dāng)找到了視圖就立即返回，不會(huì)再去匹配后面的路由規(guī)則。為了提升路由查找效率，我這里刪除了所有vbhtml的路由規(guī)則，因?yàn)槲艺麄€(gè)項(xiàng)目中都采用C#語(yǔ)言。

using System.Web.Mvc;namespace Secom.Emx.WebApp.Helper {public class CustomRazorViewEngine : RazorViewEngine{public CustomRazorViewEngine(string theme){if (!string.IsNullOrEmpty(theme)){AreaViewLocationFormats = new[]{//themes"~/themes/"+theme+"/views/Areas/{2}/{1}/{0}.cshtml","~/themes/"+theme+"/Shared/{0}.cshtml""~/Areas/{2}/Views/{1}/{0}.cshtml","~/Areas/{2}/Views/Shared/{0}.cshtml"};AreaMasterLocationFormats = new[]{//themes"~/themes/"+theme+"/views/Areas/{2}/{1}/{0}.cshtml","~/themes/"+theme+"/views/Areas/{2}/Shared/{0}.cshtml","~/themes/"+theme+"/views/Shared/{0}.cshtml","~/Areas/{2}/Views/{1}/{0}.cshtml","~/Areas/{2}/Views/Shared/{0}.cshtml"};AreaPartialViewLocationFormats = new[]{//themes"~/themes/"+theme+"/views/Shared/{0}.cshtml","~/Areas/{2}/Views/{1}/{0}.cshtml","~/Areas/{2}/Views/Shared/{0}.cshtml"};ViewLocationFormats = new[]{//themes"~/themes/"+theme+"/views/{1}/{0}.cshtml","~/Views/{1}/{0}.cshtml","~/Views/Shared/{0}.cshtml"};MasterLocationFormats = new[]{//themes"~/themes/"+theme+"/views/Shared/{0}.cshtml","~/Views/{1}/{0}.cshtml","~/Views/Shared/{0}.cshtml"};PartialViewLocationFormats = new[]{//themes"~/themes/"+theme+"/views/Shared/{0}.cshtml","~/Views/{1}/{0}.cshtml","~/Views/Shared/{0}.cshtml"};FileExtensions = new[]{"cshtml"};}}} } View Code

??? 重寫后，我們的路由規(guī)則將是這樣的：當(dāng)沒有選擇主題的情況下，沿用原來的路由規(guī)則，如果選擇了主題，則使用重寫后的路由規(guī)則。

新的路由規(guī)則：在選擇了主題的情況下，優(yōu)先查找thems/主題名稱/views/Areas/區(qū)域名稱/控制器名稱/視圖名稱.cshtml，如果找不到再按照默認(rèn)的路由規(guī)則去尋找，也就是Areas/區(qū)域名稱/Views/控制器名稱/視圖名稱.cshtml。

可以看到我們查找模板頁(yè)的方式也被修改了，所以對(duì)于一些通用的，只要換模板頁(yè)就可以了，不需要添加view界面，因?yàn)橹付ㄖ黝}下面找不到view會(huì)去默認(rèn)主題下面找，而view界面會(huì)引用模板頁(yè)的，對(duì)于一些個(gè)性化的東西，再去指定的主題下面添加新的view，不知道我這樣表述你有明白沒，感覺比較饒，反正就是你可以按照你自己的規(guī)則去找視圖，而不是asp.net mvc默認(rèn)的規(guī)則。

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??? 切換主題View代碼：

<div class="btn-group"><button type="button" class="btn btn-circle btn-outline red dropdown-toggle" data-toggle="dropdown"><i class="fa fa-plus"></i>&nbsp;<span class="hidden-sm hidden-xs">切換主題&nbsp;</span>&nbsp;<i class="fa fa-angle-down"></i></button><ul class="dropdown-menu" role="menu"><li><a href="javascript:setTheme('default')"><i class="icon-docs"></i> 默認(rèn)主題</a></li><li><a href="javascript:setTheme('Blue')"><i class="icon-tag"></i> 藍(lán)色主題</a></li></ul></div><script type="text/javascript">function setTheme(themeName){window.location.href = "/Home/SetTheme?themeName=" + themeName + "&href=" + window.location.href;}</script>

??? 當(dāng)用戶登錄成功的時(shí)候，從Cookie中讀取所選主題信息，當(dāng)Cookie中沒有讀取到主題記錄時(shí)，則從Web.config配置文件中讀取配置的主題名稱，如果都沒有讀取到，則說明是默認(rèn)主題，沿用原有的視圖引擎規(guī)則。在后臺(tái)管理界面，每次選擇了主題，我都將主題名稱存儲(chǔ)到Cookie中，默認(rèn)保存一年，這樣當(dāng)下次再登錄的時(shí)候，就能夠記住所選的主題信息了。

using System; using System.Web.Mvc; using Secom.Emx.WebApp.Helper; using System.Web; using Secom.Emx.Common.Controllers;namespace Secom.Emx.WebApp.Controllers {public class HomeController : BaseController{string themeCookieName = "Theme";public ActionResult Index(){ViewData["Menu"] = GetMenus();return View();}public ActionResult SetTheme(string themeName,string href){if (!string.IsNullOrEmpty(themeName)){Response.Cookies.Set(new HttpCookie(themeCookieName, themeName) { Expires = DateTime.Now.AddYears(1) });}else{themeName = Request.Cookies[themeCookieName].Value ?? "".Trim();}Utils.ResetRazorViewEngine(themeName);return string.IsNullOrEmpty(href)? Redirect("~/Home/Index"):Redirect(href);}public ActionResult Login(){string themeName = Request.Cookies[themeCookieName].Value ?? "".Trim();if (!string.IsNullOrEmpty(themeName)){Utils.ResetRazorViewEngine(themeName);}return View();}} }

??? Utils類：

using System.Configuration; using System.Web.Mvc;namespace Secom.Emx.WebApp.Helper {public class Utils{private static string _themeName;public static string ThemeName{get{if (!string.IsNullOrEmpty(_themeName)){return _themeName;}//模板風(fēng)格_themeName =string.IsNullOrEmpty(ConfigurationManager.AppSettings["Theme"])? "" : ConfigurationManager.AppSettings["Theme"];return _themeName;}}public static void ResetRazorViewEngine(string themeName){themeName = string.IsNullOrEmpty(themeName) ? Utils.ThemeName : themeName;if (!string.IsNullOrEmpty(themeName)){ViewEngines.Engines.Clear();ViewEngines.Engines.Add(new CustomRazorViewEngine(themeName));}}} } View Code

???? 實(shí)現(xiàn)方式實(shí)在是太簡(jiǎn)單，簡(jiǎn)單得我不知道如何表述才好，我還是記下來，方便有需要的人可以查閱，希望可以幫到你們。由于項(xiàng)目引入了龐大的各種相關(guān)文件以致文件比較大，網(wǎng)速原因無法上傳源碼還望見諒！

轉(zhuǎn)載于:https://www.cnblogs.com/jiekzou/p/7084827.html

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