js/css文件修改后浏览器本地缓存解决

时间：2016-06-22 15:44:58 阅读：195 评论：0 收藏：0 [点我收藏+]

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本文实例讲述了让html页面随js的修改来更新缓存的实现方法。分享给大家供大家参考。具体实现方法如下：

很多朋友都会碰到这样的情况：如果我们页面加载了js的话下次打开时也会是调用这个js缓存文件，但对于我们修改后调试和发布是非常的不方便了，本文就来谈论如何解决这一问题，下面一起来看看。

一、后台编写一个 UrlCommon的js/css url的连接操作类

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Web;
 6 using System.Web.Optimization;
 7 
 8 namespace WebApp.Common
 9 {
10     public abstract class UrlCommon
11     {
12         public abstract string _defaultTagFormat { get; }
13         public abstract string _verTagFormat { get; }
14         protected internal virtual String ComputeSHA1(String fileName)
15         {
16             String hashSHA1 = String.Empty;
17             if (System.IO.File.Exists(fileName))
18             {
19                 using (System.IO.FileStream fs = new System.IO.FileStream(fileName, System.IO.FileMode.Open, System.IO.FileAccess.Read))
20                 {
21                     System.Security.Cryptography.SHA1 calculator = System.Security.Cryptography.SHA1.Create();
22                     Byte[] buffer = calculator.ComputeHash(fs);
23                     calculator.Clear();
24                     StringBuilder stringBuilder = new StringBuilder();
25                     for (int i = 0; i < buffer.Length; i++)
26                     {
27                         stringBuilder.Append(buffer[i].ToString("x2"));
28                     }
29                     hashSHA1 = stringBuilder.ToString();
30                 }
31             }
32             return hashSHA1;
33         }
34         public virtual IHtmlString Url(string url, bool ver = true)
35         {
36             string absUrl = System.Web.Optimization.Scripts.Url(url).ToString();
37             string strUrl = string.Format(this._defaultTagFormat, absUrl);
38             if (ver)
39             {
40                 string filePath = System.Web.HttpContext.Current.Server.MapPath(url);
41                 string verNum = this.ComputeSHA1(filePath);
42                 //if (!string.IsNullOrWhiteSpace(verNum) && verNum.Length > 16)
43                 //{
44                 //    verNum = verNum.Substring(0, 16);
45                 //}
46                 strUrl = string.Format(this._verTagFormat, absUrl, verNum);
47             }
48             return new HtmlString(strUrl);
49         }
50     }
51     public class UrlScript : UrlCommon
52     {
53         public static UrlScript Instance = new UrlScript();
54         public override string _defaultTagFormat
55         {
56             get { return "<script src=\"{0}\"></script>"; }
57         }
58         public override string _verTagFormat
59         {
60             get { return "<script src=\"{0}?v={1}\"></script>"; }
61         }
62     }
63     public class UrlStyle : UrlCommon
64     {
65         public static UrlStyle Instance = new UrlStyle();
66         public override string _defaultTagFormat
67         {
68             get { return "<link href=\"{0}\" rel=\"stylesheet\"/>"; }
69         }
70         public override string _verTagFormat
71         {
72             get { return "<link href=\"{0}?v={1}\" rel=\"stylesheet\"/>"; }
73         }
74     }
75 }