procedure TForm1.Button2Click(Sender: TObject); var i: integer; s:string; begin s:=edit1.text; for i:=1 to length(s) do begin if not ( s[i] in ['0'..'9','.']) then begin showmessage('不是数字'); exit; end; end;end;
try strtoint(edit1.txt); except // 不是数字 end;
//键盘按下事件 procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char); begin if not (key in ['0'..'9','.']) then//如果按下的字符不是0到9和小数点 Key:=#0;//封锁键盘输入 end;
strint(edit1.text)
except
showmessage('非法数字')
end;
var i: integer;
s:string;
begin
s:=edit1.text;
for i:=1 to length(s) do
begin
if not ( s[i] in ['0'..'9','.']) then
begin
showmessage('不是数字');
exit;
end;
end;end;
strtoint(edit1.txt);
except
// 不是数字
end;
procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
if not (key in ['0'..'9','.']) then//如果按下的字符不是0到9和小数点
Key:=#0;//封锁键盘输入
end;