login_unit.~pas

delphi毕业设计02学校班级教学管理系统.ZIP

unit Login_Unit;

interface

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

type
  TfrmLogin = class(TForm)
    btnLogin: TBitBtn;
    edtUserPwd: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    edtUserID: TEdit;
    btnExit: TBitBtn;
    Image1: TImage;
    procedure btnLoginClick(Sender: TObject);
    procedure btnExitClick(Sender: TObject);
    procedure FormKeyPress(Sender: TObject; var Key: Char);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmLogin: TfrmLogin;

implementation

uses DM_Unit, Common_Unit;

{$R *.dfm}

procedure TfrmLogin.btnLoginClick(Sender: TObject);
var
  SQL :string;
begin
  SQL :='SELECT * FROM [User] WHERE UserID='
       +Quotedstr(edtUserID.Text) + ' AND UserPassword=' + Quotedstr(edtUserPwd.Text);
  if SQLSearch(SQL,DM.ADOConn) = False then
  begin
    Application.MessageBox('登录信息错误,请重新登录!','错误',16);
    edtUserPwd.Text :='';
    edtUserID.SetFocus;
    Exit;
  end
  else
    LoginUser := frmLogin.edtUserID.Text;  //登录后将登录编号赋给全局变量
  Self.Close;
end;

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

procedure TfrmLogin.FormKeyPress(Sender: TObject; var Key: Char);
begin
//回车换行
  if Key = #13 then
  begin
    Perform(WM_NEXTDLGCTL, 0, 0);
    Key := #0;
  end;
end;

end.