1. An electronic device, comprising: a touch screen, comprising: a sensing array comprising a plurality of sensors; and a display panel, comprising a displaying area, wherein a sensing area of the sensing array is smaller than or equal to the displaying area; a processor, for determining whether a user's finger touches an icon displayed on the display panel, wherein the icon corresponds to an application, wherein when the processor determines that the user's finger touches the icon displayed on the display panel, the electronic device controls a first sensing area of the sensing array corresponding to a first displaying area of the icon to enter a fingerprint sensing mode to capture a fingerprint image of the user's finger for fingerprint recognition, wherein when the processor determines that fingerprint recognition is approved, the processor activates the application corresponding to the icon.