1. An electronic device comprising: a storage unit configured to store text documents; a touch display unit configured to display the text documents, the touch display unit comprising a touch detecting module configured to generate touch signals in response to a touch by a user on the touch display unit; and a central processing unit comprising: a touch determining module configured to determine touch positions according to the touch signals generated by the touch detecting module; a control module configured to generate a first window on the touch display unit to display a text document, and determine a selected text of the displayed text document by a user according to the touch positions determined by the touch determining module, and to generate a prompt message to prompt the user to determine whether to search the selected text; a searching module configured to search occurrences of the selected text in the text document if the user determines to search the selected text, the control module configured to store the searched text in the storage unit; and a spit-screen control module configured to display a second window a whole of which being overlapped on the first window with a size thereof is smaller than that of the first window when the searched text of the selected text is stored in the storage unit, the control module configured to display each occurrence of the selected text on the second window.
1. An electronic device comprising: a storage unit configured to store text documents; a touch display unit configured to display the text documents, the touch display unit comprising a touch detecting module configured to generate touch signals in response to a touch by a user on the touch display unit; and a central processing unit comprising: a touch determining module configured to determine touch positions according to the touch signals generated by the touch detecting module; a control module configured to generate a first window on the touch display unit to display a text document, and determine a selected text of the displayed text document by a user according to the touch positions determined by the touch determining module, and to generate a prompt message to prompt the user to determine whether to search the selected text; a searching module configured to search occurrences of the selected text in the text document if the user determines to search the selected text, the control module configured to store the searched text in the storage unit; and a spit-screen control module configured to display a second window a whole of which being overlapped on the first window with a size thereof is smaller than that of the first window when the searched text of the selected text is stored in the storage unit, the control module configured to display each occurrence of the selected text on the second window. 2. The electronic device as recited in claim 1 , wherein the control module is further configured to display a dialog box to show the prompt message on the touch display unit.