一、将相对url转换成绝对url 方法

//将相对uri转换成绝对uri 实例 Uri uri = new Uri("http://www.gongjuji.net"); Uri uri2 = new Uri(uri, "abc/1234.html"); Console.WriteLine(uri2.ToString());//http://www.gongjuji.net/abc/1234.html Uri uri3 = new Uri(uri, "/md5/encrypt"); Console.WriteLine(uri3.ToString());//http://www.gongjuji.net/md5/encrypt 二、识别字符串中的链接

实例1：

string s = "例如：http://www.asd.com,http://wwww.gongjuji.net?name=zhangsan&age=10,http://md5.gongjuji.net/dencrypt/"; Regex re = new Regex(@"(?<url>http(s)?://([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?)"); MatchCollection mc = re.Matches(s); foreach (Match m in mc) { string url = m.Result("${url}"); Console.WriteLine(url); }实例2：

string s = "例如：http://www.asd.com"; Regex re = new Regex(@"(?<url>http(s)?://([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?)"); MatchCollection mc = re.Matches(s); foreach (Match m in mc) { s = s.Replace(m.Result("${url}"), String.Format("<a href='{0}'>{0}</a>", m.Result("${url}"))); } Console.WriteLine(s);

四、判断字符串是否是URL

/// <summary> /// 验证是否是URL链接 /// </summary> /// <param name="str">指定字符串</param> /// <returns></returns> public static bool IsURL(string str) { string pattern = @"^(https?|ftp|file|ws)://([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?$"; return IsMatch(pattern, str); } /// <summary> /// 判断一个字符串，是否匹配指定的表达式(区分大小写的情况下) /// </summary> /// <param name="expression">正则表达式</param> /// <param name="str">要匹配的字符串</param> /// <returns></returns> public static bool IsMatch(string expression, string str) { Regex reg = new Regex(expression); if (string.IsNullOrEmpty(str)) return false; return reg.IsMatch(str); }

三、url中添加或修改参数 

public static void Test4() { //生成random Random rand = new Random(Environment.TickCount); int num = rand.Next(1, 100); /* * http://news.sina.com.cn * http://news.sina.com.cn?page=1 * http://news.sina.com.cn?page=1&ts=1341 && * http://news.sina.com.cn?ts=14321&page=1 ?& * http://news.sina.com.cn?u=2&ts=14321&page=1 && */ string url = "http://news.sina.com.cn?u=2&ts=14321&page=1"; string ParamText = "ts"; string ParamValue = num.ToString(); Console.WriteLine(BuildUrl(url, ParamText, ParamValue)); Console.Read(); } //url里有key的值，就替换为value,没有的话就追加. public static string BuildUrl(string url, string ParamText, string ParamValue) { Regex reg = new Regex(string.Format("{0}=[^&]*", ParamText), RegexOptions.IgnoreCase); Regex reg1 = new Regex("[&]{2,}", RegexOptions.IgnoreCase); string _url = reg.Replace(url, ""); if (_url.IndexOf("?") == -1) _url += string.Format("?{0}={1}", ParamText, ParamValue);//? else _url += string.Format("&{0}={1}", ParamText, ParamValue);//& _url = reg1.Replace(_url, "&"); _url = _url.Replace("?&", "?"); return _url; }

正则匹配URL：http://blog.163.com/m13864039250_1/blog/static/213865248201681884049267/

 

C#域名操作，正则匹配域名