header - PHP导出EXCEL文件时总是自动打开，请问如何防止？

PHP导出EXCEL文件时总是自动打开，请问如何防止？

    header("Content-Type:   application/vnd.ms-excel; charset=utf-8");
    header("Content-Disposition: attachment; filename=$outputFileName");
    header("Expires: 0");
    header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
    header("Cache-Control: private", false);
    $xlsWriter->save("php://output");

回复内容：

PHP导出EXCEL文件时总是自动打开，请问如何防止？

    header("Content-Type:   application/vnd.ms-excel; charset=utf-8");
    header("Content-Disposition: attachment; filename=$outputFileName");
    header("Expires: 0");
    header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
    header("Cache-Control: private", false);
    $xlsWriter->save("php://output");

改成

<code>header('Content-Type: application/octet-stream');
</code>