begin
  if not (Key In ['0'..'9',#8]) then
    Key := #0;
end;

引言: 您好﹗ 比如說在Edit元件控制﹐可將如下程式碼寫于OnKeyPress事件中﹕

begin
  if not (Key In ['0'..'9',#8]) then
    Key := #0;
end;

#8代表Back鍵 ========================= 我是您的朋友﹐有您真好﹗ =========================