Delphi获取公网IP地址函数

引用一位仁兄的 代码

 1 uses IdHTTP;
 2 function GetPublicIP: string;
 3 var
 4   strIP, URL: string;
 5   iStart, iEnd: Integer;
 6   MyIdHTTP: TIdHTTP;
 7 begin
 8   Result := '';
 9   MyIdHTTP := TIdHTTP.Create(nil);
10   try
11     try
12       URL := MyIdHTTP.Get('http://www.ip138.com/ip2city.asp');
13     except
14     end;
15   finally
16     MyIdHTTP.Free;
17   end;
18   
19   if Length(URL) <> 0 then
20   begin
21     iStart := Pos('[', URL);
22     iEnd := Pos(']', URL);
23     if (iStart <> 0) and (iEnd <> 0) then
24     begin
25       strIP := Trim(Copy(URL, iStart + 1, iEnd - iStart - 1));
26       if strIP <> '' then
27         Result := strIP;
28     end;
29   end;
30 end;

获取公网IP地址函数，需要引用IdHTTP.