An electronic device is provided. The electronic device includes: a display apparatus and a host. The display apparatus includes a display controller and a display panel. The host executes an application to render a display image, and transmits the display image to the display controller through an image-transmission channel between the host and the display controller, and the display controller displays the display image on the display panel. The display controller determines whether an external input signal from a user satisfies a predetermined condition. In response to the external input signal satisfying the predetermined condition, the display controller triggers a virtual input signal corresponding to a specific macro key, and transmits the virtual input signal to the host through a data-transmission channel between the host and the display controller, so that the host executes a keystroke sequence corresponding to the specific macro key.