分析了明小子注入工具的源代码，发现他用的是NMHTTP控件来实现域名转IP的。
我把源代码分离了出来：
procedure TForm1.btpingClick(Sender: TObject);
begin
if Form1.SiteName.Text = '' then //判断是否有输入网址
begin
showmessage('请输入域名');
end;
Form1.NMHTTP1.Host:=Form1.SiteName.Text; //需要解析的主机
Form1.NMHTTP1.Port:=80; //设置端口
Form1.btPing.Enabled:=False;
Form1.SiteName.Enabled:=False;
try
Form1.NMHTTP1.Options(Form1.SiteName.Text);
except
showmessage('请检测域名是否输入正确,或网络连接是否正常!');
end;
Form1.NMHTTP1.Disconnect; //断开
end;

end.


但是Delphi7中没有NMHTTP控件，所以我用winsock来实现域名转IP。
记得添加winsock单元，源代码如下：
function HostToIP(Name: string; var Ip: string): Boolean;
var
wsdata : TWSAData;
hostName : array [0..255] of char;
hostEnt : PHostEnt;
addr : PChar;
begin
WSAStartup ($0101, wsdata);
try
gethostname (hostName, sizeof (hostName));
StrPCopy(hostName, Name);
hostEnt := gethostbyname (hostName);
if Assigned (hostEnt) then
if Assigned (hostEnt^.h_addr_list) then begin
addr := hostEnt^.h_addr_list^;
if Assigned (addr) then begin
IP := Format ('%d.%d.%d.%d', [byte (addr [0]),
byte (addr [1]), byte (addr [2]), byte (addr [3])]);
Result := True;
end
else
Result := False;
end
else
Result := False
else begin
Result := False;
end;
finally
WSACleanup;
end
end;

procedure TForm1.Button1Click(Sender: TObject);
var
hqw:string;
begin

HostToIP(edit1.text,hqw);
edit2.text:=hqw;

end;

end.