unit1.pas

1.改变窗体和文字颜色 2.登录窗口 3.文档编辑器

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Memo1: TMemo;
    Label1: TLabel;
    procedure Memo1KeyPress(Sender: TObject; var Key: Char);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Memo1KeyPress(Sender: TObject; var Key: Char);
begin
  if not (key in ['0','1','2','3','4','5','6','7','8','9',#8])then
  begin
  key:=#0;
  showmessage('输入字符有误');
  end;
end;

end.