如果文件名中应该有一个空格，我如何设置正确的标题?
我试着
header( "Content-Disposition: attachment; filename=a fielename with spaces.txt");
，但它只给出建议的字段名"a"，并切断其余的
$file_name = 'a fielename with spaces.txt';
header("Content-disposition: attachment; filename='"".$file_name."'"");
header( 'Content-Disposition: attachment; filename="a fielename with spaces.txt"');