【下载文档:  asp.net下URL处理两个小工具方法.txt 】

---

asp.net下URL处理两个小工具方法
有的时候我们要操作一个URL地址中查询参数，为了不破坏URL的原有结构，我们一般不能直接在URL的后面加&query=value，特别是我们的URL中有多个参数时，这种处理更麻烦。 下面两个小方法就是专门用来为一个URL添加一个查询参数或删除一个查询参数，这两个方法隐藏了原URL有无参数，是不是原来就有这个参数，有没有fragment(#anchor)这些细节和处理 /**////

/// Add a query to an URL. /// if the URL has not any query,then append the query key and value to it. /// if the URL has some queries, then check it if exists the query key already,replace the value, or append the key and value /// if the URL has any fragment, append fragments to the URL end. ///

public static string SafeAddQueryToURL(string key,string value,string url) { int fragPos = url.LastIndexOf("#"); string fragment = string.Empty; if(fragPos > -1) { fragment = url.Substring(fragPos); url = url.Substring(0,fragPos); } int querystart = url.IndexOf("?"); if(querystart < 0) { url +="?"+key+"="+value; } else { Regex reg = new Regex(@"(?<=[&\?])"+key+@"=[^\s&#]*",RegexOptions.Compiled); if(reg.IsMatch(url)) url = reg.Replace(url,key+"="+value); else url += "&"+key+"="+value; } return url+fragment; } /**////

/// Remove a query from url ///

/// /// /// public static string SafeRemoveQueryFromURL(string key,string url) { Regex reg = new Regex(@"[&\?]"+key+@"=[^\s&#]*&?",RegexOptions.Compiled); return reg.Replace(url,new MatchEvaluator(PutAwayGarbageFromURL)); } private static string PutAwayGarbageFromURL(Match match) { string value = match.Value; if(value.EndsWith("&")) return value.Substring(0,1); else return string.Empty; } 测试： string s = "http://www.cnblogs.com/?a=1&b=2&c=3#tag"; WL(SafeRemoveQueryFromURL("a",s)); WL(SafeRemoveQueryFromURL("b",s)); WL(SafeRemoveQueryFromURL("c",s)); WL(SafeAddQueryToURL("d","new",s)); WL(SafeAddQueryToURL("a","newvalue",s)); // 输出如下: // http://www.cnblogs.com/?b=2&c=3#tag // http://www.cnblogs.com/?a=1&c=3#tag // http://www.cnblogs.com/?a=1&b=2#tag // http://www.cnblogs.com/?a=1&b=2&c=3&d=new#tag // http://www.cnblogs.com/?a=newvalue&b=2&c=3#tag