Asp.net通过IP地址获得域名信息

.aspx代码

<form id="form1" method="post" runat="server">
   <font face="宋体">
    <asp:textbox id="textbox1" runat="server"
     width="248px"></asp:textbox>
    <asp:button id="button2" runat="server"
     text="转化为域名"></asp:button>
    <asp:label id="label2" runat="server"></asp:label>
    <asp:button id="button1" runat="server"
     text="转化为ip"></asp:button>
    <asp:label id="label1" runat="server">通过域名获得ip地址</asp:label></font>
  </form>

.aspx.cs代码

using system.net;

private void button1_click(object sender, system.eventargs e)
  {//转化为ip地址
   iphostentry hostinfo=dns.gethostbyname(textbox1.text);
   label2.text=hostinfo.addresslist[0].tostring();
  }

  private void button2_click(object sender, system.eventargs e)
  {//转化为域名
   iphostentry hostinfo=dns.gethostbyaddress(textbox1.text);
   label2.text=hostinfo.hostname;
  }

获得主机名和ip地址

private void page_load(object sender, system.eventargs e)
  {
   // 在此处放置用户代码以初始化页面
   dns dns;
   string hostname=dns.gethostname();
   ipaddress[] ip=dns.resolve(hostname).addresslist;
   label2.text="机器名称："+hostname.tostring()+"<br>ip地址："+ip[0].tostring();
  }