在edit中有選擇的輸入

if not(key in['0'..'9',#8]) then
   begin
     key:=#0;
     messagebeep(1);
     showmessage('密碼只能為數字' )
   end;
******************************************
e:= (Sender as TEdit); //需要限制輸入的控制項可共用這段代碼
if not(key in [#48..#57,'.','-',#8]) //可接受的字元
or(key='-')and(e.SelStart>0) //負號只能在串首
or(key='.')and(pos( '.',e.Text)>0)then key:=#0; //只接受一個小數點
***************************************
procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
    begin
      if not (key in ['0'..'9',Chr(VK_BACK),Chr(VK_Delete)]) then
      begin
        key:=#0;
        Messagebeep(0);
      end;
    end;