unit1.~pas

本光盘是《Delphi 7应用教程》一书的配套光盘

unit Unit1;

interface

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

type
  TYHDL = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Edit1: TEdit;
    Edit2: TEdit;
    Table1: TTable;
    DataSource1: TDataSource;
    procedure FormCreate(Sender: TObject);
    procedure Edit1KeyPress(Sender: TObject; var Key: Char);
    procedure Edit2KeyPress(Sender: TObject; var Key: Char);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  YHDL: TYHDL;
  YHM:String;
  GLY:Boolean;
  KL:String;

implementation

var
  time:integer;

{$R *.dfm}

procedure TYHDL.FormCreate(Sender: TObject);
  var
    curdir:string;
begin
   getdir(0,Curdir);
   table1.DatabaseName :=Curdir;
   Table1.TableName:='User.db';
   Table1.Open ;
   time:=0;
end;

procedure TYHDL.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
  if ord(key)=13 then
    begin
       Table1.IndexFieldNames :='UserName';
       Table1.SetKey ;
       Table1.FieldByName('UserName').AsString :=Edit1.Text ;
       If Table1.GotoKey  then
          begin
             Edit2.SetFocus ;
             Time:=0;
          end
          else
             begin
               time:=time+1;
               if time<=2 then
                  ShowMessage('用户名非法，请重输！')
               else
                 begin
                    ShowMessage('你是非法用户，不能进入系统！');
                    Table1.Close;
                    Application.Terminate ;
                 end;

             end;
    end;
end;

procedure TYHDL.Edit2KeyPress(Sender: TObject; var Key: Char);
begin
 If Ord(Key) = 13 Then
      If Table1.FieldByName('PASSWORD').AsString   <> Edit2.Text Then
         begin
            time := time + 1;
            If time < 3 Then
                begin
                    ShowMessage ('口令错误，请重新输入！');
                    Edit2.Text := '';
                    Edit2.SetFocus;
                end
            Else
              Begin
                 ShowMessage ('对不起，你无法进入系统！');
                 Close;
              end   
         end
         Else
           begin
              ShowMessage('欢迎你进入系统');
              YHM:=Table1.FieldByName('Username').AsString ;
              GLY:=Table1.FieldByName('Admin').AsBoolean ;
              KL:=Table1.FieldByName('PassWord').Asstring ;
              Table1.Close;
              YHDL.Hide ;
             // MainForm.Show;
           end;
 end;

end.