<?php echo form_close();?>

controller代碼:
 function upload() {
        $config['upload_path'] = './uploads/';
        /*這里的uploads是相對于index.php的,也就是入口文件,這個千萬不要弄錯哦!
        否則就會報錯"The upload path does not appear to be valid.";
        */
        $config['allowed_types'] = 'gif|jpg|png';
        /*我試著去上傳其它類型的文件,這里一定要注意順序!
        A problem was encountered while attempting to move the uploaded file to the final destination.
        這個錯誤一般是上傳文件的文件名不能是中文名,這個很郁悶!還未解決,大家可以用其它方法,重新改一下文件名就可以解決了! 
        $config['allowed_types'] = 'zip|gz|png|gif|jpg';(正確)
        $config['allowed_types'] = 'png|gif|jpg|zip|gz';(錯誤)
        */
        $config['max_size'] = '1024';
        $config['max_width']  = '1024';
        $config['max_height']  = '768';

        $config['file_name']  = time(); //文件名不使用原始名
        $this->load->library('upload', $config);
        if(!$this->upload->do_upload()) {
                echo $this->upload->display_errors();
        }else{

             $data['upload_data']=$this->upload->data();  //文件的一些信息
             $img=$data['upload_data']['file_name'];  //取得文件名

             echo $img."<br>";

             foreach($data['upload_data'] as $item => $value){
             echo $item.":".$value."<br>";

            }

       }
}