如何在不执行的情况下在Apache上托管PHP文件？

If I host a PHP file on Apache, it will just be executed. I want clients to be able to download the PHP file without changing the .php extension. I don't want to disable PHP either.

if you don't want to play with apache configuration or .htaccess, then use PHP itself to get it done

create a file showcode.php with following code

echo file_get_contents('/path/to/your/php/file/having/viewable/code/for/users/');