2017年計(jì)算機(jī)二級(jí)《JAVA》考前模擬簡(jiǎn)單應(yīng)用試題

三、簡(jiǎn)單應(yīng)用題
    本題使用下拉菜單來(lái)控制字體，窗口中有一個(gè)標(biāo)簽和一個(gè)下拉菜單，當(dāng)選中下拉菜單中的任一項(xiàng)字體時(shí)，標(biāo)簽上字符串的字體就隨之改變。
    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    class ComboBoxFrame extends JFrame {
    public ComboBoxFrame(){
    setTitle("java2");
    setSize(300，200);
    addWindowListener(new WindowAdapter(){
    public void windowClosing(WindowEvent e){
    System.exit(0);
    }
    });
    style=new JComboBox()：
    style.setEditable(true);
    style.addhem("Serif");
    style.addItem("SansSerif");
    style.addhem("Monospaced");
    style.addhem("Dialog");
    style.addhem("Dialoglnput");
    style.addActionListener(this);
    JPanel p=new JPanel();
    P.add(style);
    getContentPane().add(p，"South");
    panel=new ComboBoxTestPanel();
    getContentPane().add(panel，"Center");
    }
    public void actionPerformed(ActionEvent evt){
    JComboBox source=(JComboBox) ;
    String item=(String)source.getSelectedhem()：
    panel.setStyle(item);
    }
    private ComboBoxTestPanel panel;
    private JComboBox style;
    }
    class ComboBoxTestPanel extends JPanel{
    public ComboBoxTestPanel(){
    setStyle("Serif");
    }
    public void setStyle(String s){
    setFont(new Font(S，F(xiàn)ont.PLAIN，12));
    repaint();
    }
    public void paintComponent(Graphics g){
    super.paintComponent(g);
    9.drawString("Welcome to China!"，0，50);
    }
    }
    public class java2{
    public static void main(String[]args){
    JFrame frame=new ComboBoxFrame();
    frame.show();
    }
    }