如何删除警告无法修改标头信息-标头已发送

Question

出现“已发送标题”警告。我关闭$zip->close(); 但仍然显示警告

$zip = new ZipArchive;
$download = 'new_zip.zip';
$zip->open($download, ZipArchive::CREATE);
foreach (glob("zipfile/*") as $file) { 
    $zip->addFile($file);
}
$zip->close();
header('Content-Type: application/zip');
header("Content-Disposition: attachment; filename = $download");
header('Content-Length: ' . filesize($download));
header("Location: $download");

Answer 1

在脚本的开头，使用：

<?php ob_start(); ?>

然后在脚本末尾添加：

<?php ob_flush(); ?>