//上for Delphi6
var a:integer;
var c:integer;
begin
val(edit.text, a, c); //c返回出错的位置
if c <> 0 then
showmessage('不是整数');
end;
var a:integer;
var c:integer;
begin
val(edit.text, a, c); //c返回出错的位置
if c <> 0 then
showmessage('不是整数');
end;
//上for Delphi6
//上for Delphi6
~~~~~~~~~~~~~~~~
//下for Turbo Pascal 5.0
: if (key not in ['0'..'9']) then
key := key
else
key := #0;