Request.url用法

我們在開發網頁應用程式，時常需要去解析網址(Request.Url)的每個片段，進行一些判斷。例如說 "http://localhost:1897/News/Press/Content.aspx/123?id=1#toc"，我們想要取得網址裡第一層目錄的名字(News)用以判斷不同的頁面標題(Page Title)。

我看很多人都用字串的 IndexOf 方法與 Substring 方法：

Request.Url.PathAndQuery.Substring(1, Request.Url.PathAndQuery.IndexOf("/", 1)-1)

這實在太埋沒 .NET 的強大設計了，事實上在 Request 物件就已經提供很多方便的屬性(Property)可供取得網址的片段。

底下這張表就是各種跟 Browser Request 的網址相關的屬性與用法：

網址：http://localhost:1897/News/Press/Content.aspx/123?id=1#toc
Request.ApplicationPath	/
Request.PhysicalPath	D:\Projects\Solution\web\News\Press\Content.aspx
System.IO.Path.GetDirectoryName(Request.PhysicalPath)	D:\Projects\Solution\web\News\Press
Request.PhysicalApplicationPath	D:\Projects\Solution\web\
System.IO.Path.GetFileName(Request.PhysicalPath)	Content.aspx
Request.CurrentExecutionFilePath	/News/Press/Content.aspx
Request.FilePath	/News/Press/Content.aspx
Request.Path	/News/Press/Content.aspx/123
Request.RawUrl	/News/Press/Content.aspx/123?id=1
Request.Url.AbsolutePath	/News/Press/Content.aspx/123
Request.Url.AbsoluteUri	http://localhost:1897/News/Press/Content.aspx/123?id=1
Request.Url.Scheme	http
Request.Url.Host	localhost
Request.Url.Port	1897
Request.Url.Authority	localhost:1897
Request.Url.LocalPath	/News/Press/Content.aspx/123
Request.PathInfo	/123
Request.Url.PathAndQuery	/News/Press/Content.aspx/123?id=1
Request.Url.Query	?id=1
Request.Url.Fragment
Request.Url.Segments	/ News/ Press/ Content.aspx/ 123

所以當你看了這張表之後，你還會想用 Request.Url.PathAndQuery.Substring(1, Request.Url.PathAndQuery.IndexOf("/", 1)-1) 這種寫法嗎？

用這樣寫 Request.Url.Segments[1].Replace("/", "") 不是又短又直覺嗎？ ^_^

以下是產生以上表格的程式碼：

    protected void Page_Load(object sender, EventArgs e)
    {

        StringBuilder sb = new StringBuilder();

        sb.Append("<table cellpadding=3 cellspacing=0 border=1>");

        sb.Append("<tr><td colspan=2>");
        sb.Append("網址："http://localhost:1897/News/Press/Content.aspx/123?id=1#toc">http://localhost:1897/News/Press/Content.aspx/123?id=1#toc        sb.Append("</td></tr>"); ");

        // Request.ApplicationPath
        sb.Append("<tr><td>");
        sb.Append("Request.ApplicationPath");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.ApplicationPath + "</b>");
        sb.Append("</td></tr>");

        // Request.PhysicalPath
        sb.Append("<tr><td>");
        sb.Append("Request.PhysicalPath");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.PhysicalPath + "</b>");
        sb.Append("</td></tr>");

        // System.IO.Path.GetDirectoryName(Request.PhysicalPath)
        sb.Append("<tr><td>");
        sb.Append("System.IO.Path.GetDirectoryName(Request.PhysicalPath)");
        sb.Append("</td><td>");
        sb.Append("<b>" + System.IO.Path.GetDirectoryName(Request.PhysicalPath) + "</b>");
        sb.Append("</td></tr>");

        // Request.PhysicalApplicationPath
        sb.Append("<tr><td>");
        sb.Append("Request.PhysicalApplicationPath");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.PhysicalApplicationPath + "</b>");
        sb.Append("</td></tr>");

        // System.IO.Path.GetFileName(Request.PhysicalPath)
        sb.Append("<tr><td>");
        sb.Append("System.IO.Path.GetFileName(Request.PhysicalPath)");
        sb.Append("</td><td>");
        sb.Append("<b>" + System.IO.Path.GetFileName(Request.PhysicalPath) + "</b>");
        sb.Append("</td></tr>");

        // Request.CurrentExecutionFilePath
        sb.Append("<tr><td>");
        sb.Append("Request.CurrentExecutionFilePath");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.CurrentExecutionFilePath + "</b>");
        sb.Append("</td></tr>");

        // Request.FilePath
        sb.Append("<tr><td>");
        sb.Append("Request.FilePath");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.FilePath + "</b>");
        sb.Append("</td></tr>");

        // Request.Path
        sb.Append("<tr><td>");
        sb.Append("Request.Path");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.Path + "</b>");
        sb.Append("</td></tr>");

        // Request.RawUrl
        sb.Append("<tr><td>");
        sb.Append("Request.RawUrl");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.RawUrl + "</b>");
        sb.Append("</td></tr>");

        // Request.Url.AbsolutePath
        sb.Append("<tr><td>");
        sb.Append("Request.Url.AbsolutePath");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.Url.AbsolutePath + "</b>");
        sb.Append("</td></tr>");

        // Request.Url.AbsoluteUri
        sb.Append("<tr><td>");
        sb.Append("Request.Url.AbsoluteUri");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.Url.AbsoluteUri + "</b>");
        sb.Append("</td></tr>");

        // Request.Url.Scheme
        sb.Append("<tr><td>");
        sb.Append("Request.Url.Scheme");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.Url.Scheme + "</b>");
        sb.Append("</td></tr>");

        // Request.Url.Host
        sb.Append("<tr><td>");
        sb.Append("Request.Url.Host");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.Url.Host + "</b>");
        sb.Append("</td></tr>");

        // Request.Url.Port
        sb.Append("<tr><td>");
        sb.Append("Request.Url.Port");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.Url.Port + "</b>");
        sb.Append("</td></tr>");

        // Request.Url.Authority
        sb.Append("<tr><td>");
        sb.Append("Request.Url.Authority");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.Url.Authority + "</b>");
        sb.Append("</td></tr>");

        // local Request.Url.LocalPath
        sb.Append("<tr><td>");
        sb.Append("Request.Url.LocalPath");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.Url.LocalPath + "</b>");
        sb.Append("</td></tr>");

        // Request.PathInfo
        sb.Append("<tr><td>");
        sb.Append("Request.PathInfo");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.PathInfo + "</b>");
        sb.Append("</td></tr>");

        // Request.Url.PathAndQuery
        sb.Append("<tr><td>");
        sb.Append("Request.Url.PathAndQuery");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.Url.PathAndQuery + "</b>");
        sb.Append("</td></tr>");

        // Request.Url.Query
        sb.Append("<tr><td>");
        sb.Append("Request.Url.Query");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.Url.Query + "</b>");
        sb.Append("</td></tr>");

        // Request.Url.Fragment
        // 原則上你應該無法從 Request.Url.Fragment 取得任何資料，因為通常 Browser 不會送出 #toc 這個部分
        sb.Append("<tr><td>");
        sb.Append("Request.Url.Fragment");
        sb.Append("</td><td>");
        sb.Append("<b>" + Request.Url.Fragment + "</b>");
        sb.Append("</td></tr>");

        // Request.Url.Segments
        sb.Append("<tr>");
        sb.Append("<td>");
        sb.Append("Request.Url.Segments");
        sb.Append("</td>");
        sb.Append("<td>");
        string[] segments = Request.Url.Segments;
        foreach (string s in segments)
        {
            sb.Append("<b>" + s + "</b>");
            sb.Append("<br/>");
        }
        sb.Append("</td>");
        sb.Append("</tr>");

        sb.Append("</table>");

        ltlTable.Text = sb.ToString();
    }