public MainFrame(){
        setTitle("Ϣ");     //ñ
        JPanel contentPanel=new JPanel(new BorderLayout()); //
        this.setContentPane(contentPanel);

        JLabel infoJbl=new JLabel("Ϣ");
        infoJbl.setFont(new   java.awt.Font("Dialog",   1,   15));  //

        JPanel centerJp=new JPanel(new BorderLayout());     //centerʾ
        centerJp.add(infoJbl,BorderLayout.CENTER);
        contentPanel.add(centerJp,BorderLayout.CENTER);
        addMenu();      //Ӳ˵
        addToolbar();   //ӹ
    }