How to download files in ZendFramework

How to download files in ZendFramework is as follows: My goal is to download files in a controller method. the downloaded files are not files in the local directory, it is a temporary data file generated in the controller method. Without ZF, PHP can set the header information for the browser to implement the download function. how can I implement the file download function in head Zend Framework?
For example, my goal is to download files in a controller method.
The downloaded file is not a file in the local directory, but a temporary data file generated in the controller method.
Without ZF, PHP can set the header information for the browser to download,
Header ("Content-type: text/plain ");
Header ("Accept-Ranges: bytes ");
Header ("Content-Disposition: attachment; filename =". $ filename );
Header ("Cache-Control: must-revalidate, post-check = 0, pre-check = 0 ");
Header ("Pragma: no-cache ");
Header ("Expires: 0 ");
Just like this, but in ZF, I put this code directly into a controller method, such as downloadController's downloadAction (). in the same way, I set the header information and print the data,
Print $ data;
But cannot be downloaded.
Could you tell me how experts can download files in zend framework, or does ZF have any built-in file downloads. After reading the manual, it seems that only files are uploaded. No Download
------ Solution --------------------
Layout and viewRenderer must be disabled.
Public function downloadAction (){
$ This-> _ helper-> getHelper ('layout ')-> disableLayout ();
$ This-> _ helper-> getHelper ('viewrenderer')-> setNoRender ();

...

}