Delphi的类和对象（九）- 类运算符as、is

var
  i: integer;
begin
  if Edit1.ClassType = Edit2.ClassType then
  ShowMessage(‘类相同‘);

  if Edit1.ClassType <> Edit2.ClassType then
  ShowMessage(‘类不相同‘);

  for i:= 0 to Self.ControlCount-1 do
  begin
    if Self.Controls[i] is TEdit then
      Self.Controls[i].Enabled:= False;
  end;

  for i:=0 to Self.ControlCount-1 do
  begin
    if Self.Controls[i] is TEdit then
      (Controls[i] as TEdit).Color:= clInfoBk;
  end;
end;