unit1.pas

delphi中用ADO控件写的简单的登录界面

unit Unit1;

interface

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

type
  Tdenglu = class(TForm)
    Label1: TLabel;
    Edit1: TEdit;
    Label2: TLabel;
    Edit2: TEdit;
    Button1: TButton;
    Button2: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  denglu: Tdenglu;
  mypath: string;
  times:integer;
implementation

{$R *.dfm}
uses
 unit_dm,unit2;

procedure Tdenglu.FormCreate(Sender: TObject);
begin
     mypath:=extractfilepath(paramstr(0));
     times:=0;
end;

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

procedure Tdenglu.Button1Click(Sender: TObject);
var
userID,password:string;

begin
   times:=times+1;
   userID:= edit1.Text;
   password:=edit2.Text;
  with DM.ADOQuery1 do
  begin
   dm.ADOQuery1.Close;
   dm.ADOQuery1.SQL.Clear;
   dm.ADOQuery1.SQL.Add('select * from users where username='''+userID+''' and  passwords='''+password+'''');
  // dm.ADOQuery1.Parameters.ParamByName('ID').Value:=edit1.Text;
   dm.ADOQuery1.Open;
   if dm.ADOQuery1.RecordCount=1
    then
    begin
    // logintimes:=0;
     denglu.Hide;
     form2.Show;
     end
     else
     begin
     if MessageDlg('密码输入错误，是否退出？',mtConfirmation,[mbYes,mbNo],0)=mrYes then close 
     else if times<3 then edit2.SetFocus
     else
     begin
     MessageDlg('对不起，密码输入错误超过三次！',mtInformation,[mbok],0);
     dm.ADOQuery1.Close;
     denglu.Close;
     end;
     end;
     end;

     
end;

end.