C++核心技術登陸實現

void CLMSDlg::OnButtonlogin()
{
 // TODO: Add your control notification handler code here
 CMainsystem dlg;
 CADOConn adoconn;
 CString sqlstr,str;
 int countcleck;
 countcleck=((CComboBox*)GetDlgItem(IDC_COMBOCLECK))->GetCurSel();
 ((CComboBox*)GetDlgItem(IDC_COMBOCLECK))->GetLBText(countcleck,str);
 
 UpdateData(TRUE);
 if(m_user.IsEmpty())
 {
  MessageBox("用戶名不能爲空","錯誤",MB_ICONERROR);
  GetDlgItem(IDC_EDITUSER)->SetFocus();
 }
 try
 {
  sqlstr.Format("select *from usertable where uusername='%s' and uuserpassword='%s' and uusercleck='%s'",m_user,m_password,str);
  _bstr_t vSQL;
  vSQL=(_bstr_t)sqlstr;
  _RecordsetPtr m_recordset;  
  m_recordset=adoconn.GetRecordSet(vSQL);
  
  CString str1,str2,str3;
  str1=(LPCSTR)(_bstr_t)(m_recordset->GetCollect("uusername"));
  str2=(LPCSTR)(_bstr_t)(m_recordset->GetCollect("uuserpassword"));
  str3=(LPCSTR)(_bstr_t)(m_recordset->GetCollect("uusercleck"));
  str1.TrimRight();
  str2.TrimRight();
  str3.TrimRight();
  if(str1==m_user || str2==m_password || str3==str)
  {
   MessageBox("恭喜你，登陸成功!","正確",MB_ICONQUESTION);
   this->EndDialog(1);
   dlg.DoModal();
  }
 }
 catch(...)
 {
  MessageBox("操做失敗","錯誤",MB_ICONERROR);
  m_user="";
  m_password="";
  GetDlgItem(IDC_EDITUSER)->SetFocus();
  UpdateData(false);
 }
}