其他答案指出，您需要在每个字段后添加行尾字符.

As other answers state, you need to add in an end of line character after each field.

但是，不同的操作系统使用不同的行尾，因此，例如，"\ n"可能不会在Windows上显示为新行.正如Mahdi所说，您可以使用Windows样式的"\ r \ n"行尾，也可以使用 PHP_EOL 常量，以便输出适合服务器的行尾，在这种情况下，您的代码应类似于

Different OS's use different line endings, though, and so a "\n" may not display as a new line on Windows, for example. As Mahdi said, you can use Windows style "\r\n" line endings, or you can use the PHP_EOL constant so that line endings appropriate to the server will be output, in which case your code would look like

$data = $_POST['name'] . PHP_EOL;
$data .= $_POST['email'] . PHP_EOL;
$data .= $_POST['message'] . PHP_EOL;