Method of operating handheld electronic device and touch interface apparatus and storage medium using the same

A method of operating a handheld electronic device and a touch interface apparatus and a storage medium using the same are provided. In this method, an operating interface displayed on a touch screen of the handheld electronic device is used to operate a function module of the handheld electronic device. First, the function module of the handheld electronic device is activated to display a user interface corresponding to the function module on the touch screen. Next, an operating function of the function module is activated, so as to display a corresponding operating interface on the touch screen. In the meantime, the user interface of the function module is reduced simultaneously and displayed on an area of the touch screen excluding the operating interface. Accordingly, a convenient operating interface is provided for the user to operate while the content of original displayed frame remains.