Abstract: A touchpad device includes a touch module, communication unit, memory unit, and processing unit. The processing unit receives a touch input sensed by the touch module, performing touch operation detection, and sending one or more operation signals to a terminal device through the communication unit. The processing unit, when detecting a first touch operation occurs on a first mouse button region and ends, sends an operation signal including indication of continuous pressing of a virtual mouse button. The processing unit, when detecting a second touch operation is a sliding movement of a single touch point after the first touch operation ends, sends coordinates-related messages of the sliding movement. The processing unit, when detecting a third touch operation after the first touch operation ends, sends operation signals including a message indicating release of the virtual mouse button and a message indicating an instruction corresponding to the third touch operation.