php codeigniter zip文件崩溃

Question

我有多个图像，并打包到zip文件中以下载图像。当我单击下载时，zip文件大小为404字节，并且zip文件崩溃。什么问题使我的zip文件崩溃了 file download zip file

public function download_order_zipped_files() {
        $this->data['kode_order'] = $this->GET('kode_order', true);
        if (!isset($this->data['kode_order']))
    {
        echo('kok gaada');
        exit;
    }
        $this->load->model('order_m');
        $this->data['order']            = $this->order_m->get_row(['kode_order' => $this->data['kode_order']]);
        $zipname=$this->data['kode_order']."_".$this->data['order']->nama_penerima."_".$this->data['order']->waktu_order.".zip";
    if ( $this->POST( 'download' ) ) {


        $files = $this->POST( 'files' );

        # create new zip opbject
        $zip = new ZipArchive();

        # create a temp file & open it
        $tmp_file = tempnam('.','');
        $zip->open($tmp_file, ZipArchive::CREATE);

        # loop through each file
        foreach($files as $file){

            # download file
            $download_file = file_get_contents($file);

            #add it to the zip
            $zip->addFromString(basename($file),$download_file);

        }

        # close zip
        $zip->close();


        # send the file to the browser as a download
        header('Content-disposition: attachment; filename="'.$zipname.'"');
        header('Content-type: application/zip');
        readfile($tmp_file);

    }