工作总结：检查字符串合法性(C++)

BOOL CLiftCtrlModbusConfigDlg::CheckValid(const CString &str)
{
 ASSERT(str.GetLength() > 0);
 if ((str[0] == '-' && str[1] > '0' && str[1] <= '9')|| (str[0] > '0' && str[0] <= '9' && str.GetLength() >= 1) || (str[0] == '0' && str.GetLength() == 1))
 {
  for (int i = 1; i < str.GetLength(); i++)
  {
   if(!isdigit(str[i]))
   {
    return FALSE;
   }
  }
  return TRUE;
 }
 return FALSE;
}