如何制作简易菜单?

爱被打了一巴掌 2022-07-14 01:23 225阅读 0赞

实现一个菜单组件包括下拉菜单和弹出菜单,实现框图如下:

![Center][]

创建下拉菜单的基本过程:

1).新建一个JFrame框架.JFrame frame=new JFrame();

2).新建一个菜单栏:菜单栏是窗口中的主菜单，用来包容一组菜单，只有一种构造方法:JMenuBar().

3).把菜单栏放到新建框架frame的上方,在JFrame,JApplet和JDialog中定义了setJMenuBar()方法.  
4).创建菜单:JMenu(),把菜单放在放到菜单栏中用add()方法,把二级子菜单放到菜单中也用add()方法.

5).添加下划线:addSeparator().

创建弹出菜单的基本过程:

弹出式菜单可以根据需要显示指定的位置.

1).加入菜单项和子菜单的方法类似下拉菜单

2).在显示弹出式菜单的时候必须调用show()方法.

实现代码>

package Menu;
    
    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    
    public class Menu extends MouseAdapter implements ActionListener{
    	JFrame frame=new JFrame();
    	JPopupMenu menu=new JPopupMenu();
    	public static void main(String[] args)
    	{
    		Menu m=new Menu();
    		m.go();
    	}
    	public void go()
    	{
    		JMenuBar mb=new JMenuBar();
    		frame.setJMenuBar(mb);
    		JMenu m;
    		JMenu sub;
    		JMenuItem item;
    		
    		m=new JMenu("文件");
    		m.setMnemonic(KeyEvent.VK_G);
    		mb.add(m);
    		item=new JMenuItem("打开");
    		item.setAccelerator(KeyStroke.getKeyStroke(
    		KeyEvent.VK_1, ActionEvent.ALT_MASK));
    		m.add(item);
    		item=new JMenuItem("保存",KeyEvent.VK_S);
    		item.setEnabled(false);
    		m.add(item);
    		item=new JMenuItem("关闭");
    		item.setMnemonic(KeyEvent.VK_C);
    		m.add(item);
    		m.addSeparator();
    		item=new JMenuItem("退出");
    		item.setMnemonic(KeyEvent.VK_E);
    		item.addActionListener(this);
    		m.add(item);
    		
    		m=new JMenu("格式");
    		m.setMnemonic(KeyEvent.VK_S);
    		mb.add(m);
    		sub=new JMenu("字体");
    		m.add(sub);
    		item=new JMenuItem("宋体");
    		item.setAccelerator(KeyStroke.getKeyStroke(
    		KeyEvent.VK_S, ActionEvent.ALT_MASK));
    		sub.add(item);
    		item=new JMenuItem("黑体",KeyEvent.VK_H);
    		item.setAccelerator(KeyStroke.getKeyStroke(
    		KeyEvent.VK_H, ActionEvent.ALT_MASK));
    		sub.add(item);
    		sub=new JMenu("颜色");
    		m.add(sub);
    		item=new JMenuItem("红色",KeyEvent.VK_Q);
    		sub.add(item);
    		item=new JMenuItem("黑色",KeyEvent.VK_B);
    		sub.add(item);
    		m.addSeparator();
    		JCheckBoxMenuItem cb = new JCheckBoxMenuItem("自动换行",true);
    		m.add(cb);
    		m.addSeparator();
    		JRadioButtonMenuItem rm = new JRadioButtonMenuItem("大",true);
    		ButtonGroup g = new ButtonGroup();
    		m.add(rm);
    		g.add(rm);
    		rm = new JRadioButtonMenuItem("小");
    		m.add(rm);
    		g.add(rm);
    		
    		m=new JMenu("编辑");
    		mb.add(m);
    		item = new JMenuItem("复制");
    		item.setAccelerator(KeyStroke.getKeyStroke(
    		KeyEvent.VK_C, ActionEvent.ALT_MASK));
    		m.add(item);
    		item=new JMenuItem("粘贴");
    		m.add(item);
    		m.addSeparator();
    		item=new JMenuItem("替换");
    		m.add(item);
    		item=new JMenuItem("全选");
    		item.setAccelerator(KeyStroke.getKeyStroke(
    		KeyEvent.VK_A, ActionEvent.ALT_MASK));
    		m.add(item);
    		
    		JMenuItem it=new JMenuItem("剪切",KeyEvent.VK_J);    //弹出菜单
    		menu.add(it);
    		menu.addSeparator();
    		it=new JMenuItem("复制",KeyEvent.VK_F);
    		item.setAccelerator(KeyStroke.getKeyStroke(
    		KeyEvent.VK_F, ActionEvent.ALT_MASK));
    		menu.add(it);
    		sub=new JMenu("字体");
    		menu.add(sub);
    		it=new JMenuItem("宋体");
    		it.setAccelerator(KeyStroke.getKeyStroke(
    		KeyEvent.VK_S, ActionEvent.ALT_MASK));
    		sub.add(it);
    		it=new JMenuItem("黑体");
    		it.setAccelerator(KeyStroke.getKeyStroke(
    		KeyEvent.VK_B, ActionEvent.ALT_MASK));
    		sub.add(it);
    		it=new JMenuItem("加粗");
    		it.setAccelerator(KeyStroke.getKeyStroke(
    		KeyEvent.VK_J, ActionEvent.ALT_MASK));
    		sub.add(it);
    		menu.add(sub);
    		it=new JMenuItem("段落",KeyEvent.VK_D);
    		menu.add(it);
    		it=new JMenuItem("退出");
    		it.addActionListener(this);
    		menu.add(it);
    		
    		Container con=frame.getContentPane();
    		con.addMouseListener(this);
    		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    		frame.setSize(300,300);
    		frame.setVisible(true);
    	}
    	public void mousePressed(MouseEvent e)
    	{
    		PopUpShow(e);
    	}
    	public void mouseReleased(MouseEvent e)
    	{
    		PopUpShow(e);
    	}
    	private void PopUpShow(MouseEvent e)
    	{
    		if(e.isPopupTrigger())
    		{
    			menu.show(e.getComponent(),e.getX(),e.getY());
    		}
    	}
    	public void actionPerformed(ActionEvent e)
    	{
    		if(e.getActionCommand() == "退出")
    		{
    			System.exit(0);
    		}
    	}
    }

实现结果:

![Center 1][] ![Center 2][] ![Center 3][] ![Center 4][]

![Center 5][] ![Center 6][]

[Center]: /images/20220714/eb904c157a034d5c9d46df843130dcdf.png
[Center 1]: https://img-blog.csdn.net/20161202173513521?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
[Center 2]: https://img-blog.csdn.net/20161202173529897?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
[Center 3]: https://img-blog.csdn.net/20161202173542428?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
[Center 4]: /images/20220714/33f4a45c659144039d53b7b1e29ba985.png
[Center 5]: https://img-blog.csdn.net/20161202173611906?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
[Center 6]: /images/20220714/079cb555dfa34629b0ab5ac0ea6ad21a.png