太久沒用紀錄一下
感謝保哥知識分享

舉例我們的為網址：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？ ^_^

注意事項

當程式部署(Deploy)到 IIS 6 之後，假設你的網址是 http://localhost:1897/News/Press/Content.aspx/123? ，IIS 不知為何會將問號 ( ? ) 給刪除掉，以致於 ASP.NET 使用 Request.Url.Query 是空字串！如果你的程式有判斷到這部分時就要特別注意，因為照理說應該會抓到才對！不知道是不是 IIS 6 的 Bug

資料來源 來自 The Will Will Web
=>
https://blog.miniasp.com/post/2008/02/10/How-Do-I-Get-Paths-and-URL-fragments-from-the-HttpRequest-object