procedure TForm1.Edit1KeyDown(Sender: TObject; var Key: Word;
var KeyChar: Char; Shift: TShiftState);
var
i: Boolean;
begin
i := (keyChar <= #8) or (KeyChar<=#8) and (KeyChar<#48) or (KeyChar >#57) ;
if i then
keyChar := #0;
// if not (keyChar in [‘0‘..‘9‘,#13]) then KeyChar :=#0;
end;
在OnKeyDown中判断KeyChar的条件，以前delphi7里一般都在OnKeyPress事件下写
if not (key in [‘0‘..‘9‘,#13]) then Key :=#0;
XE的FMX里没有OnKeyPress事件，一次在OnKeyDown下写，而Key参数是Word类型，所以要用到KeyChar
原文：http://www.cnblogs.com/studypanp/p/5114205.html