获取当前域名

<script language="javascript">
//获取域名
host = window.location.host;
host2=document.domain; 

//获取页面完整地址
url = window.location.href;

document.write("<br>host="+host)
document.write("<br>host2="+host2)
document.write("<br>url="+url)
</script>

<?
//获取当前的域名:
echo $_SERVER['SERVER_NAME'];
//获取来源网址,即点击来到本页的上页网址
echo $_SERVER["HTTP_REFERER"];
?>

HttpContext.Current.Request.Url.ToString()

public static String getDomain(String curl){
  URL url = null;
  String q = "";
  try {
   url = new   URL(curl);
   q = url.getHost();
  } catch (MalformedURLException e) {   
 
  }
  url = null;
  return q;
 }

祝你好运！！！