php微信图片防盗链 PHP怎样解决微信文章图片防盗链

function actionWechatImg()
{
  header('Content-type: image/jpg');
  $url = $_GET['url'];
  $refer = "http://www.qq.com/";
  $opt = [
      'http'=>[
        'header'=>"Referer: " . $refer
      ]
      ];
  $context = stream_context_create($opt); 
  $file_contents = file_get_contents($url,false, $context);
  echo $file_contents;
}