网址规范函数完成（Url Normalize）即相对地址的补全

接上文  url的规范化问题, 今天有空把这个函数完成了。基本没有对输入做检测，所以用的时候请注意哦

函数功能：将相对网址，根据页面地址补全为绝对网址.

 class Program
    {
        static void Main(string[] args)
        {

            string baseUrl1 = "http://aifunv.com/?p=18";
            string url = "?p=2";
            Console.WriteLine(NormalizeUrl(baseUrl1, url));

            baseUrl1 = "http://aifunv.com/";
            url = "?p=2";
            Console.WriteLine(NormalizeUrl(baseUrl1, url));

            baseUrl1 = "http://www.aifunv.com/download/editor.htm";
            url = "../sitemap.html";
            Console.WriteLine(NormalizeUrl(baseUrl1, url));

            baseUrl1 = "http://www.aifunv.com/download/temp/editor.htm";
            url = "http://www.cnblogs.com/sitemap.html";//
            Console.WriteLine(NormalizeUrl(baseUrl1, url));

            baseUrl1 = "http://www.aifunv.com/";
            url = "#top";
            Console.WriteLine(NormalizeUrl(baseUrl1, url));

            baseUrl1 = "http://www.aifunv.com/index";
            url = "/page1.html";
            Console.WriteLine(NormalizeUrl(baseUrl1, url));

            baseUrl1 = "http://www.aifunv.com/index/";
            url = "page1.html";
            Console.WriteLine(NormalizeUrl(baseUrl1, url));

            baseUrl1 = "http://www.aifunv.com";
            url = "//l.aifunv.com/spirit/logo.gif";
            Console.WriteLine(NormalizeUrl(baseUrl1, url));

            Console.ReadKey();
        }

        /// <summary>
        /// 规范网址
        /// </summary>
        /// <param name="BaseUrl"></param>
        /// <param name="Url"></param>
        /// <returns></returns>
       public static string NormalizeUrl(string BaseUrl, string Url)
        {
            // <a href="?pageNo=2">第 2 頁</a>
            if (Url.StartsWith("?"))
            {
                int index = BaseUrl.IndexOf("?");
                if (index > 0)
                {
                    return BaseUrl.Substring(0, index) + Url;
                }
                else
                {
                    return BaseUrl + Url;
                }
            }

            // # 上層目錄的 sitemap.aspx 頁面
            // <a href="../sitemap.aspx
            //-----------
            // # 上兩層目錄的 default.htm 頁面
            // <a href="http://www.cnblogs.com/default.htm
            //-----------
            // # 上層目錄下的 images 目錄下的 dot 目錄下的 red.gif 檔案
            // <a href="../images/dot/red.gif
            if (Url.StartsWith("../"))
            {
                string temp = Url;

                int lastIndex = BaseUrl.LastIndexOf("/");
                BaseUrl = BaseUrl.Substring(0, lastIndex);

                while (Url.StartsWith("../"))
                {
                    lastIndex = BaseUrl.LastIndexOf("/");
                    BaseUrl = BaseUrl.Substring(0, lastIndex);
                    Url = Url.Substring(3);
                }
                return BaseUrl + "/" + Url;
            }

            //<img src="//l.yimg.com/tw.yimg.com/i/tw/hp/spirit/yahoo_logo.gif" />
            if (Url.StartsWith("//"))
            {
                int lastIndex = BaseUrl.LastIndexOf("//");
                if (lastIndex > 0)
                {
                    BaseUrl = BaseUrl.Substring(0, lastIndex);
                }
                return BaseUrl + Url;
            }

            // <a href="/index.aspx
            if (Url.StartsWith("/"))
            {
                int lastIndex = BaseUrl.LastIndexOf("/");
                if (lastIndex > 0)
                {
                    BaseUrl = BaseUrl.Substring(0, lastIndex);
                }
                return BaseUrl + Url;
            }

            // <a href="#top
            if (Url.StartsWith("#"))
            {
                int lastIndex = BaseUrl.LastIndexOf("#");
                if (lastIndex > 0)
                {
                    BaseUrl = BaseUrl.Substring(0, lastIndex);
                }
                return BaseUrl + Url;
            }

            // # 同目錄下的 step2.aspx 頁面
            // <a href="step2.aspx
            int _lastIndex = BaseUrl.LastIndexOf("/");
            if (_lastIndex > 0)
            {
                BaseUrl = BaseUrl.Substring(0, _lastIndex + 1);
            }
            return BaseUrl + Url;

        }
    }

我的博客哦