dlunit1.~pas

这是一个Delphi很好很全面知识的实例

unit DLUnit1;

interface

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

type
  TDLForm = class(TForm)
    GroupBox1: TGroupBox;
    GroupBox2: TGroupBox;
    Image1: TImage;
    GroupBox3: TGroupBox;
    Label1: TLabel;
    Label2: TLabel;
    Edit1: TEdit;
    Edit2: TEdit;
    BitBtn1: TBitBtn;
    BitBtn2: TBitBtn;
    procedure BitBtn1Click(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    isadmin:boolean;
  end;

var
  DLForm: TDLForm;
   loginsuccessed:boolean;
implementation

uses  MDUnit1;

{$R *.dfm}

procedure TDLForm.BitBtn1Click(Sender: TObject); //确定
begin
if (edit1.text='')or(edit2.Text='') then
      messagedlg('请正确填写姓名和密码！',mtwarning,[mbok],0)
  else
  begin
    md.ADOMMQuery3.Close;
    md.ADOMMQuery3.SQL.Clear;
    md.ADOMMQuery3.SQL.Add('select * from 密码表');
    md.ADOMMQuery3.SQL.Add('where 用户名=:user_name and 密码=:pass');
    md.ADOMMQuery3.Parameters.ParamByName('user_name').Value:=edit1.Text;
    md.ADOMMQuery3.Parameters.ParamByName('pass').Value:=edit2.Text;
    md.ADOMMQuery3.Open;
    if md.ADOMMQuery3.RecordCount >=1 then
    begin
      if md.ADOMMQuery3.FieldByName('权限').Value='0' then
         isadmin:=true;  //具有系统管理员权限
         loginsuccessed:=true;
         //mainform.StatusBar1.Panels[1].Text:='操作人员：'+dlform.Edit1.Text;
         dlform.Close;
      end  //关闭登陆窗体，进入主窗体
    else
      messagedlg('没有此用户或密码错误，请重新登陆！',mtwarning,[mbok],0);
      edit1.clear;
      edit2.Clear;
  end;
end;

procedure TDLForm.BitBtn2Click(Sender: TObject); //退出
begin
if not loginsuccessed then
     application.Terminate;
end;

end.