cw_login.pas

结于初学者来说这对数据库是一个很好的例子

unit cw_login;

interface

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

type
  TForm2 = class(TForm)
    Database2: TDatabase;
    Table1: TTable;
    T_user: TTable;
    Q_operator: TQuery;
    Label1: TLabel;
    GroupBox1: TGroupBox;
    Label2: TLabel;
    Label3: TLabel;
    PassWord: TEdit;
    Button1: TButton;
    Button2: TButton;
    username: TComboBox;
    procedure FormShow(Sender: TObject);
    procedure usernameSelect(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure PassWordKeyPress(Sender: TObject; var Key: Char);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form2: TForm2;

implementation

uses cw_main;

{$R *.dfm}

procedure TForm2.FormShow(Sender: TObject);
begin
 table1.Active:=False;
 Table1.Active:=True;
 while not table1.Eof do
 begin
   username.Items.Add(table1.fieldbyname('name').AsString);
   table1.Next;
 end;
 table1.Active:=False;
end;

procedure TForm2.usernameSelect(Sender: TObject);
begin
 password.SetFocus;
end;

procedure TForm2.Button1Click(Sender: TObject);
begin
    T_user.Filter:='Name='''+UserName.Text+'''';
    T_user.Filtered:=True;
    T_user.Open;
  if T_user.RecordCount=1 then
    begin
      if (T_user['Pass']=PassWord.Text) and ((T_user['managerright']=9) or (T_user['managerright']=8)) then
        begin
          form2.Hide;
          form1.operator.Caption:=username.Text;
          if T_user['managerright']=8 then
           begin
               form1.Button1.Enabled:=False;
               form1.Button2.Enabled:=False;
               form1.Button3.Enabled:=False;
               form1.Button4.Enabled:=False;
               form1.Button5.Enabled:=False;
               form1.Button6.Enabled:=False;
               form1.Button7.Enabled:=False;
               form1.Button8.Enabled:=False;
               form1.Button9.Enabled:=False;
               form1.Button10.Enabled:=False;
               form1.Button11.Enabled:=False;
               form1.Button12.Enabled:=False;
               form1.Button13.Enabled:=False;
               form1.Button14.Enabled:=False;
               form1.Button15.Enabled:=False;
               form1.Button16.Enabled:=False;
               form1.Button17.Enabled:=False;
               form1.Button18.Enabled:=False;
               form1.Button21.Enabled:=False;
               form1.Button19.Enabled:=False;
               form1.Button24.Enabled:=False;
               form1.Button25.Enabled:=False;
               form1.Button26.Enabled:=False;
               form1.Button29.Enabled:=False;
               form1.Button30.Enabled:=False;
               form1.Button31.Enabled:=False;
           end;
          form1.show;
       end
     else
        begin
            Application.MessageBox('您无此操作权限，请重新选择用户！','用户错误',MB_OK);
            password.SetFocus;
        end
    end
    else
      begin
        Application.MessageBox('请确认用户名是否正确！','无此用户',MB_OK);
        username.SetFocus;
      end;




end;

procedure TForm2.Button2Click(Sender: TObject);
begin
 close;
end;

procedure TForm2.PassWordKeyPress(Sender: TObject; var Key: Char);
begin
 if key=#13 then
 begin
    key:=#0;
    perform(WM_NEXTDLGCTL,0,0);
 end;
end;

end.