学步园

我们在开发网页应用程序,时常需要去解析网址(Request.Url)的每个片段,进行一些判断｡例如说 "http://localhost:1897/News/Press/Content.aspx/123?id=1#toc",我们想要取得网址里第一层目录的名字(News)用以判断不同的页面标题(Page Title)｡

我看很多人都用字符串的 IndexOf 方法与 Substring 方法:

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

这实在太埋没 .NET 的强大设计了,事实上在 Request 对象就已经提供很多方便的属性(Property)可供取得网址的片段｡

底下这张表就是各种跟 Browser Request 的网址相关的属性与用法:
网址: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

所以当你看了这张表之后,你还会想用 Request.Url.PathAndQuery.Substring(1, Request.Url.PathAndQuery.IndexOf("/", 1)-1) 这种写法吗?

用这样写 Request.Url.Segments[1].Replace("/", "") 不是又短又直觉吗? ^_^

以下是产生以上表格的程序代码:

    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("网址:"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
        // 原则上你应该无法从 Request.Url.Fragment 取得任何数据,因为通常 Browser 不会送出 #toc 这个部分
        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();
    }