jta.setFont((new Font("宋体", Font.BOLD, 12)));
else if("楷体".equals(actionCommand))
jta.setFont((new Font("楷体", Font.PLAIN, 12)));
else if("Arial".equals(actionCommand))
else if("Pink".equals(actionCommand))
jta.setForeground(Color.pink);
else if("Blue".equals(actionCommand))
jta.sLeabharlann tForeground(Color.blue);
else if("宋体".equals(actionCommand))
jmb.add(jm3);
jta=new JTextArea("Hello Java!!
");
con.add(jp,BorderLayout.SOUTH);
jmi1.addActionListener(this);
jmi2.addActionListener(this);
jmi3.addActionListener(this);
JTextArea jta; JMenuItem jmi1,jmi2,jmi3,jmi4,jmi5,jmi6,jmi7,jmi8; public MenuShow(){
setTitle("菜单演示"); Container con=getContentPane(); BorderLayout bl=new BorderLayout(); JPanel jp=new JPanel(); JMenuBar jmb=new JMenuBar(); setJMenuBar(jmb); JMenu jm1=new JMenu("Color"); jmi1=new JMenuItem("Yellow"); jmi2=new JMenuItem("Orange"); jmi3=new JMenuItem("Pink"); jmi4=new JMenuItem("Blue"); jm1.add(jmi1); jm1.add(jmi2); jm1.add(jmi3); jm1.add(jmi4); JMenu jm2=new JMenu("Style"); jmi5=new JMenuItem("宋体"); jmi6=new JMenuItem("楷体"); jmi7=new JMenuItem("Arial"); jmi8=new JMenuItem("Times New Roman"); jm2.add(jmi5); jm2.add(jmi6); jm2.add(jmi7); jm2.add(jmi8); JMenu jm3=new JMenu("Exit"); jmb.add(jm1); jmb.add(jm2);
jmi4.addActionListener(this);
jmi5.addActionListener(this);
jmi6.addActionListener(this);
jmi7.addActionListener(this);
jmi8.addActionListener(this);
jp.add(jta);
setSize(300,250);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public void actionPerformed(ActionEvent e){
String actionCommand=e.getActionCommand();
jta.setFont((new Font("Arial", Font.ITALIC, 12)));
else if("Times New Roman".equals(actionCommand))
jta.setFont((new Font("Times New Roman", Font.BOLD, 12)));
}
}
public static void main(String args[]){
MenuShow ms=new MenuShow();
}
}
if(e.getSource() instanceof JMenuItem ){
if("Yellow".equals(actionCommand))
jta.setForeground(Color.yellow);
else if("Orange".equals(actionCommand))
jta.setForeground(Color.orange);
编写程序，建立一个带有菜单的窗体。当用户选择“Color”或“Style”菜单的相关选项时， 标签中文字的字体和颜色会发生相应的变化。运行界面如下。
import java.awt.*; import java.awt.event.*; import javax.swing.*; public class MenuShow extends JFrame implements ActionListener{