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)
    Label1: TLabel;
    Label2: TLabel;
    Edit1: TEdit;
    Edit2: TEdit;
    Button1: TButton;
    Button2: TButton;
    procedure Edit2Change(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Edit2Change(Sender: TObject);
begin
   Button1.Enabled:=true;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
   if(Edit1.Text='Admin')and(Edit2.Text='111111')
   then showmessage('登录成功')
   else
   begin
     if Edit2.Tag>=3then
       begin
        showmessage('非法用户');
        close
       end
     else
     begin
     showmessage('密码错误，请重新输入');
     Edit2.SetFocus;
     Edit2.SelectAll;
     Edit2.Tag:=Edit2.Tag+1;
     Button1.Enabled:=False;
     end;
   end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
close;
end;

end.