unit1.pas

用delphi写的课堂作业

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Button1: TButton;
    Button2: TButton;
    Label3: TLabel;
    Button3: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

  UserType: string;
  UserName: string;
  DataFile: string;
implementation
uses Unit2;
{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
ADOQuery1: TADOQuery;
begin
  {数据库操作：判断用户和密码是否正确}
  if (edit1.Text<>'') and (edit2.Text<>'') then
  begin
    ADOQuery1:= TADOQuery.Create(self);
    ADOQuery1.ConnectionString := 'Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\zhang\data\zl.mdb;Persist Security Info=False';
    ADOQuery1.SQL.Clear;
    ADOQuery1.SQL.Add('select * from master where mname="'+edit1.Text+'" and password="'+edit2.Text+'" ');
    ADOQuery1.Open;
    if (edit1.Text=ADOQuery1.FieldByName('mname').AsString) and (edit2.Text=ADOQuery1.FieldByName('password').AsString) then
    begin
      {用户和密码正确，登录成功，并获取用户的权限类型}
      UserType := ADOQuery1.FieldByName('type').AsString;
      UserName := ADOQuery1.FieldByName('mname').AsString;
      ADOQuery1.Free;
      Form1.Hide;
      form2.ShowModal;
    end

  else
    application.MessageBox('用户名或者密码错误，登录失败!','提示');
    edit1.Text:='';
    edit2.Text:='';
    edit1.SetFocus;
    end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
edit1.Text:='';
edit2.Text:='';
edit1.SetFocus;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
application.Terminate;
end;

end.