asp.net 获取网站地址（不是请求地址）

this.Request.Url.GetLeftPart(UriPartial.Authority)

可以获得http://www.baidu.com，无论是什么请求。另外，根据不同的UriPartial枚举值，可以得到path、QueryString等字符串。

一下内容来源：http://www.xueit.com/html/2009-03/21_932_00.html

---------------------------------------------------------------------

获取网站根目录的urli源代码

public static string GetRootURI()
{
string AppPath = "";
HttpContext HttpCurrent = HttpContext.Current;
HttpRequest Req;
if (HttpCurrent != null)
{
Req = HttpCurrent.Request;

string UrlAuthority = Req.Url.GetLeftPart(UriPartial.Authority);
if (Req.ApplicationPath == null || Req.ApplicationPath == "/")
//直接安装在 Web 站点
AppPath = UrlAuthority;
else
//安装在虚拟子目录下
AppPath = UrlAuthority + Req.ApplicationPath;
}
return AppPath;
}