Disclosed are methods and systems for displaying media data, host computers, devices, and media. A method of triggering electronic signage to display media data, which is executable at a wireless access device, includes: receiving, from a host computer, media data carrying a signage identifier for uniquely identifying the electronic signage; and sending the media data to the electronic signage to which the signage identifier belongs, to trigger the electronic signage to display the media data. A method of triggering electronic signage to display media data, which is executable at a host computer, includes: sending media data carrying a signage identifier for uniquely identifying the electronic signage to a wireless access device, to trigger the electronic signage to display the media data.