根據url下載圖片看起來很簡單，做起來還是有點曲折的

首先，直接file_put_content()的話可以下載圖片但不知道圖片儲存在什麼位置，所以必須要呼叫瀏覽器下載，使用header頭。

function download($url,$filename )
{
    $title=substr($filename,strrpos($filename,'/')+1);
    $file  =  fopen($url, "rb");
    Header( "Content-type:  application/octet-stream ");
    Header( "Accept-Ranges:  bytes ");
    Header( "Content-Disposition:  attachment;  filename= $title");  //以附件方式下載並在瀏覽器顯示
    $contents = "";
    while (!feof($file)) {  //檢查是否到檔案尾
        $contents .= fread($file, 8192);
    }
    echo $contents;

}
 

但是這個函式不能迴圈批處理下載，若要批量下載需要打包zip

    function download_image($url, $fileName , $dirName, $fileType = array('jpg', 'gif', 'png'), $type = 1)
    {
        if ($url == '')
        {
            return false;
        }

        // 獲取檔案原檔名
        $defaultFileName = $fileName;
        // 獲取檔案型別
        $suffix = substr(strrchr($url, '.'), 1);
        if (!in_array($suffix, $fileType))
        {
            return false;
        }

        // 設定儲存後的檔名
        $fileName = $fileName == '' ? time() . rand(0, 9) . '.' . $suffix : $defaultFileName;

        // 獲取遠端檔案資源
        if ($type)
        {
            $ch = curl_init();
            $timeout = 30;
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
            $file = curl_exec($ch);
            curl_close($ch);
        }
        else
        {
            ob_start();
            readfile($url);
            $file = ob_get_contents();
            ob_end_clean();
        }

        if (!file_exists($dirName))
        {
            mkdir($dirName, 0777, true);
        }
        // 儲存檔案
        $res = fopen($dirName . '/' . $fileName, 'a');
        fwrite($res, $file);
        fclose($res);

        return array(
            'fileName' => $fileName,
            'saveDir' => $dirName
        );
    }
 

$zip = new ZipArchive();
$zipname = "./qrcode.zip";
$dir =   dirname(__FILE__).'/image' ;
if ($zip->open($zipname, ZIPARCHIVE::CREATE)!==TRUE) {
    exit('不存在');
}

foreach ($images as $url){
    $filename =substr($url,strrpos($url,'/')+1);
    download_image($url,$filename,$dir);
    $zip->addFile( $dir.'/'.$filename,$filename);
}

$zip->close();


header("Cache-Control: public");
header("Content-Description: File Transfer");
header('Content-disposition: attachment; filename='.basename($zipname)); //檔名
header("Content-Type: application/zip"); //zip格式的
header("Content-Transfer-Encoding: binary"); //告訴瀏覽器，這是二進位制檔案
header('Content-Length: '. filesize($zipname));

@readfile($zipname);
 

然後瀏覽器就會以zip壓縮包的形式就行下載了，親測可用。