public function uploadImage($userfile = 'userfile'){

  //公共部分不作为参数，可变部分作为参数   /*   $config['upload_path'] = './uploads/';   $config['allowed_types'] = 'gif|jpg|png';   $config['max_size'] = '2000';   $config['max_width'] = '1024';   $config['max_height'] = '768';*/   $config = $this->config->item('upload_p_w_picpath');   $config['file_name'] = date("YmdHis").rand(100,999);

  $this->load->library('upload', $config);

  $this->upload->initialize($config);   //参数：$_FILES数组的标签   if($this->upload->do_upload($userfile)){    $fileInfo = $this->upload->data();    $_POST['p_w_picpath'] = $config['upload_path'].$fileInfo['file_name'];    $this->thumbImage($config['upload_path'].$fileInfo['file_name']);   }  }  public function thumbImage($source_p_w_picpath,$new_p_w_picpath=null){   $config = $this->config->item('thumb_p_w_picpath');//参数为config数组标签名   $config['source_p_w_picpath'] = $source_p_w_picpath;   $config['new_p_w_picpath'] = $config['thumb_path'].$new_p_w_picpath;   $this->load->library('p_w_picpath_lib', $config);   $this->p_w_picpath_lib->initialize($config);//以防万一，文档例子不可行时，加上此句   $this->p_w_picpath_lib->resize();  }