delphi三十六之编辑篇

3．将编辑控件修改为只能输入指定精度的数字

Procedure TForm1.Edit1Change(Sender: Tobject);

const precision = 2;

var

　li,lk, HasDot, HasReduce: integer;

RestNum: Integer;

ls,ls1: string;

hasdigit: boolean;

begin with (Sender as Tedit) do begin lk:=SelStart;

HasDot := 0;

HasReduce := 0;

hasdigit:=false;

ls:=text;

ls1:=ls;

for li:=1 to length(ls) do begin case ls[li] of "0".."9":

begin hasdigit:=true;

if HasDot $#@60;$#@62; 0 then begin //确定小数位数

RestNum := Length(Ls1) - Pos(".", ls1);

if RestNum $#@62; precision then

Delete(ls1, Length(Ls1), 1);

end;

end;