用一个判断函数就行了。
function TCSForm.IsLegalIP(IP:string):boolean;
var
i, j, l: integer;
ips: array [1..4] of string;
begin
i:=1;
for l:=1 to 4 do ips[l]:='';
for j:=1 to length(ip) do
if ip[j]<>'.' then
begin
if (ip[j]<'0')or(ip[j]>'9') then
begin
//showmessage(ip[j]);
Result:=false;
exit;
end;
ips[i]:=ips[i]+ip[j]
end
else inc(i);
if (i<>4)
or((strtoint(ips[1])>255)or(strtoint(ips[1])<0)) //originally is <1
or((strtoint(ips[2])>255)or(strtoint(ips[2])<0))
or((strtoint(ips[3])>255)or(strtoint(ips[3])<0))
or((strtoint(ips[4])>255)or(strtoint(ips[4])<0)) then
Result:= false
else
Result:= true;
end;