.NET MVC扩展UrlHelper支持CDN

Posted on 2017-07-08 09:33 WebEnh 阅读(323) 评论(0) 收藏举报

0x00、为什么要扩展

　　因为我的服务器是小水管，加载一个完整的网站往往需要很久，想加速网站加载速度，静态文件最好是分离出来，所有就想到了扩展UrlHelper，用来支持CDN加载文件。

0x01、论引用静态文件的几种方法

以 jquery-1.11.0.min.js 为例，一般常用的有以下两种(我自己的情况)

<script src="~/Content/themes/plugins/jQuery/jquery-1.11.0.min.js"></script>
<script src="@Url.Content("~/Content/themes/plugins/jQuery/jquery-1.11.0.min.js")"></script>

@Url.Content("") 形式是UrlHelper的方法，我们今天就来扩展它

0x02、扩展的代码

新建一个UrlHelperExtensions 类

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Mvc;
 
namespace Chenmo.Soft.WebUI.Framework
{
    public static class UrlHelperExtensions
    {
        /// <summary>CSS cdn
        /// 
        /// </summary>
        /// <param name="helper"></param>
        /// <param name="contentPath"></param>
        /// <returns></returns>
        public static string CdnCssContent(this UrlHelper helper, string contentPath)
        {
            return GetContent(helper, contentPath, "CSS");
        }
 
        /// <summary>JS cdn
        /// 
        /// </summary>
        /// <param name="helper"></param>
        /// <param name="contentPath"></param>
        /// <returns></returns>
        public static string CdnJsContent(this UrlHelper helper, string contentPath)
        {
            return GetContent(helper, contentPath, "JS");
        }
 
        /// <summary>img cdn
        /// 
        /// </summary>
        /// <param name="helper"></param>
        /// <param name="contentPath"></param>
        /// <returns></returns>
        public static string CdnImgContent(this UrlHelper helper, string contentPath)
        {
            return GetContent(helper, contentPath, "IMG");
        }
 
        private static string GetContent(this UrlHelper helper, string contentPath, string type)
        {
            var result = helper.Content(contentPath);
            if (ConfigurationManager.AppSettings[$"CDN_{type}_Enable"].ToUpper() == "TRUE")
            {
                result = ConfigurationManager.AppSettings[$"CDN_{type}_URL"]
                         + contentPath.TrimStart('~');
            }
            return result;
        }
    }
}

　　同时在web.config 中的appSettings节点添加一下配置

<!--是否开启CDN True False-->
<add key="CDN_CSS_Enable" value="True" />
<add key="CDN_CSS_URL" value="http://css.static.ofnhkb1.com" />
 
<add key="CDN_JS_Enable" value="True" />
<add key="CDN_JS_URL" value="http://js.static.ofnhkb1.com" />
 
<add key="CDN_IMG_Enable" value="True" />
<add key="CDN_IMG_URL" value="http://img.static.ofnhkb1.com" />