ulogin.pas

水电管理系统,介绍了水电管理系统的基本结构和基本功能,对进行这方面的开发人员有一定帮助

unit uLogin;

interface

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

type
  TfrmLogin = class(TForm)
    Label1: TLabel;
    Edit1: TEdit;
    BitBtn1: TBitBtn;
    BitBtn2: TBitBtn;
    ADOQuery1: TADOQuery;
    DataSource1: TDataSource;
    procedure FormCreate(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure FormDestroy(Sender: TObject);
    procedure BitBtn1Click(Sender: TObject);
  private
    { Private declarations }
    Function GetPassWd: String;
  public
    { Public declarations }
    IsOk: Boolean;
    iTime: Integer;  //计算登录次数
  end;

var
  frmLogin: TfrmLogin;

implementation

uses UCommon, uConst;

{$R *.DFM}


procedure TfrmLogin.FormCreate(Sender: TObject);
begin
  ADOQuery1.ConnectionString := Format(strConnectString, [ExtractFilePath(Application.ExeName)]);

  if not FileExists(ExtractFilePath(Application.ExeName) + '\MDB\SDManager.mdb') then
  Begin
    MessageBox(Handle, '数据库文件不存在！', '错误', MB_OK or MB_ICONERROR);
    Application.Terminate;
  end
  else begin
    Try
      ADOQuery1.Connection;
    except
      MessageBox(Handle, 'ErrorConnectDataBase', '错误', MB_OK or MB_ICONERROR);
      Application.Terminate;
    end;
  end; 
end;

procedure TfrmLogin.BitBtn2Click(Sender: TObject);
begin
  Application.Terminate;
end;

procedure TfrmLogin.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  Action := caFree;
end;

procedure TfrmLogin.FormDestroy(Sender: TObject);
begin
  frmLogin := nil;
end;

procedure TfrmLogin.BitBtn1Click(Sender: TObject);
var
  PS: String;
begin
  IsOk := False;

  PS := Trim(Edit1.Text);

  if PS <> GetPassWd then
  begin
    if iTime >= 2 then begin
      MessageBox(Handle, '你无权使用本系统！', '提示', MB_OK or MB_ICONINFORMATION);
      Application.Terminate;
    end;

    MessageBox(Handle, '输入的密码不正确，请确认！', '登录提示', MB_OK or MB_ICONINFORMATION);
    Edit1.SetFocus;
    IsOk := False;
    Inc(iTime);
  end
  else begin
    IsOk := True;
    frmLogin.Close;
  end;

end;

function TfrmLogin.GetPassWd: String;
begin
  //todo
  if not ADOQuery1.Active then ADOQuery1.Open;
  Result := ADOQuery1.Fields[0].AsString;
end;

end.