图像下载无效。它直接读

Question

图像下载无效。它直接读取而不是下载。

if($_REQUEST['image'] == true){

    $URl = $post->guid; 
    echo $URl;
    header("Content-Type: image/png");
    header('Content-Description: File Transfer');
    header("Cache-Control: no-cache, validated");
    header('Content-Type: application/octet-stream');
    header("Content-Disposition: attachment; filename=\"".basename($URl)."\"");
    header('Content-Transfer-Encoding: binary');
    var_dump(readfile($URl)); 
    die; 
} 

Answer 1

尝试此标题格式

 header("Content-type: application/octet-stream"); 
 header("Content-Length: " . filesize($filename)); 
 header("Content-Disposition: attachment; filename=$filename"); 
 header('Content-Transfer-Encoding: binary'); 
 header('Cache-Control: must-revalidate, post-check=0, pre-check=0');  
 fpassthru($fp);