denglu.~pas

有不足之处请指出

unit denglu;

interface

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

type
  TdengluForm = class(TForm)
    Panel1: TPanel;
    Label1: TLabel;
    Label2: TLabel;
    Edit2: TEdit;
    ComboBox1: TComboBox;
    Button1: TButton;
    Button2: TButton;
    Query1: TQuery;
    Query1Bianhao: TStringField;
    Query1Xingming: TStringField;
    Query1Quanxian: TStringField;
    Query1Mima: TStringField;
    Label3: TLabel;
    Label4: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure Edit2KeyPress(Sender: TObject; var Key: Char);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  dengluForm: TdengluForm;
  count:integer;
  quanxian:string;
  yonghu:string;
  havelogon:boolean;

implementation


{$R *.dfm}

procedure TdengluForm.Button1Click(Sender: TObject);
begin

 if Combobox1.Text=''then
    begin
      messageDlg('请输入或选择用户名!',mtInformation,[mbOk],0);
      ComboBox1.SetFocus ;
      exit;
    end;
 if Edit2.Text =''  then
    begin
      MessageDlg('请输入密码!',mtInformation,[mbOk],0);
      Edit2.SetFocus ;
      exit;
    end;
 if (ComboBox1.Text<>'') and (Edit2.Text <>'') then
     begin
       count:=count+1;
       Query1.Close;
       Query1.SQL.Clear ;
       Query1.Params.Clear ;
       Query1.Params.CreateParam(ftstring,'xm',ptinput).AsString :=ComboBox1.Text ;
       Query1.SQL.Add('select * from yonghu where xingming=:xm');
       try
         Query1.Open
       Except
         MessageDlg('无此用户！',mtError,[mbOk],0)
       end;
       if (Edit2.Text=Query1mima.Value) then
          begin
          messagedlg('成功登录',mtInformation,[mbOk],0);
          yonghu:=ComboBox1.Text;
          quanxian:=Query1quanxian.Value ;
          havelogon:=true;
          dengluform.Hide;
          havelogon:=True;
          dengluform.close;
          end
       else
          begin
            messageDlg('密码不正确!',mtError,[mbOk],0);
            Edit2.Clear ;
            Edit2.SetFocus ;
            if count=3 then
              begin
                messageDlg('连续登录三次失败，将退出程序!',mtWarning,[mbOk],0);
                Application.Terminate ;
              end;
          end;
    end;

end;

procedure TdengluForm.Button2Click(Sender: TObject);
begin
 Application.Terminate ;
end;

procedure TdengluForm.FormShow(Sender: TObject);
var i:integer;
begin

  havelogon:=False;
  count:=0;
  Query1.Close;
  Query1.SQL.Clear ;
  Query1.Params.Clear ;
  Query1.SQL.Add('select * from yonghu;');
  Query1.ExecSQL ;
  Query1.Open ;
  Query1.First ;
  ComboBox1.Clear ;
  i:=0;
  while not Query1.Eof do
    begin
     ComboBox1.Items.Insert(i,Query1xingming.Value);
     Query1.Next ;
     i:=i+1;
    end;
 Query1.Close;
end;

procedure TdengluForm.Edit2KeyPress(Sender: TObject; var Key: Char);
begin
 if key=#13 then
 Button1.Click ;
end;

end.