Abstract: The present invention relates to a purchasing and copy protecting method for a digital content, comprising the steps of: a user of an electronic device buying a digital content from a supplier through a network, wherein the electronic device at least includes a set of first identification codes and a connection port; the supplier storing the digital content along with the a set of second identification codes in a medium, and storing a set of third identification codes in a storage device, wherein the storage device can access the medium; the supplier delivering the storage device and/or the medium to the user; and the user inserting the medium into the storage device, and connecting the electronic device to the storage device, then the electronic device checking whether the first identification codes, the second identification codes and the third identification codes are matched or not; if yes, then the electronic device can read the medium in the storage device; if not, then the electronic device can not rea

Abstract: A method of playing images on a portable electronic device is disclosed to include the steps of: providing a portable electronic device that comprises a display device, a browser program, a USB port, a USB OTG module, and a memory, and said browser program includes an editing function; connecting a digital camera device to said portable electronic device, and said digital camera device comprises a display device, a USB port, and a memory; thereby said USB OTG module detects whether or not said memory of said digital camera device includes a multimedia file; if yes, then call said browser program and display said multimedia file on said display device; and a user using said editing function to operate said multimedia file on said portable electronic device. The present invention also relates to a portable electronic device, which can control playing images of a digital camera device on the portable electronic device.