2. The apparatus according to claim 1 , wherein the input action detection circuit comprises: a pressure detection sub-circuit configured to detect a press parameter that is generated by pressing the handwriting input apparatus when the user performs the suspending handwriting input; an action determination sub-circuit connected to the pressure detection sub-circuit and configured to determine the input action of the user as an active motion when the press parameter is greater than or equal to a preset threshold value, and to determine the input action of the user as a shift motion when the press parameter is less than the preset threshold value.
2. The apparatus according to claim 1 , wherein the input action detection circuit comprises: a pressure detection sub-circuit configured to detect a press parameter that is generated by pressing the handwriting input apparatus when the user performs the suspending handwriting input; an action determination sub-circuit connected to the pressure detection sub-circuit and configured to determine the input action of the user as an active motion when the press parameter is greater than or equal to a preset threshold value, and to determine the input action of the user as a shift motion when the press parameter is less than the preset threshold value. 3. The apparatus according to claim 2 , wherein the action determination sub-circuit is further configured, when the user performs the suspending handwriting input, to determine the input action of the user as an inactive motion, if coordinates of a cursor on a display screen of the display device corresponding to the input action go beyond a display range of the display device, or if the display screen of the display device is served as a handwriting input plane for the suspending handwriting input, and the angle formed by the plane and a normal line of the display screen of the display device is greater than a preset angle.