procedure TForm1.Edit1Exit(Sender: TObject);
begin
if Length(Edit1.Text)>3 then
begin
ShowMessage('请重新输入');
(Sender as TEdit).SetFocus;
exit;
end;
try
strtofloat(Edit1.Text);
if pos('.',Edit1.Text)<> 2 then
begin
ShowMessage('请重新输入');
(Sender as TEdit).SetFocus;
end;
except
ShowMessage('请重新输入');
(Sender as TEdit).SetFocus;
end;
end;
设Edit1.Maxlength:=3;
在edit.onpress中
var str:string;
begin
str:=Edit.text;
if (length(str)=0)or(length=2) then
begin
if key not in ['1'..'9'] then
key=#0;
end
else if (length(str)=1 then
if key not in['.'] then
key=#0;
end;