PHP 导出带有 BOM 的 CSV UTF-8 不起作用

PHP导出带有BOM的UTF-8编码的CSV文件时遇到问题

php
// 设置编码和BOM
$encoding = "UTF-8";
$bom = chr(239) . chr(187) . chr(191);
// 创建CSV文件
$filename = "example.csv";
$file = fopen($filename, "w");
// 写入BOM
fwrite($file, $bom);
// 写入CSV数据
$data = array(
    array("姓名", "年龄", "性别"),
    array("张三", "25", "男"),
    array("李四", "30", "女"),
);
foreach ($data as $row) {
    fputcsv($file, $row);
}
fclose($file);
// 下载CSV文件
header("Content-Type: text/csv; charset=" . $encoding);
header("Content-Disposition: attachment; filename=" . $filename);
readfile($filename);
?>