java界面版四则运算

本是古典何须时尚 2022-05-17 12:16 180阅读 0赞

菜单栏 JMenubar, 菜单JMenu  菜单项：JMenuItem,菜单栏位于窗口的顶部，菜单放置在菜单栏上，菜单下拉可以看到子菜单。

package com.util.ljc;
    
    import java.awt.GridLayout;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JMenu;
    import javax.swing.JMenuBar;
    import javax.swing.JMenuItem;
    import javax.swing.JPanel;
    import javax.swing.JTextField;
    
    public class Meau extends JFrame  implements ActionListener {
    	JMenuItem m1,m2,m3,m4,m5;
    	JTextField jt1,jt2,jt3;
    	Meau(){
    		this.setSize(250, 300);
    		JMenuBar mb=new JMenuBar();//菜单栏
    		JMenu jm=new JMenu("运算");//菜单
    		 m1=new JMenuItem("加");//创建菜单项
    		 m3=new JMenuItem("减");//创建菜单项
    		 m4=new JMenuItem("乘");//创建菜单项
    		 m5=new JMenuItem("除");//创建菜单项
    		jm.add(m1);
    		jm.add(m3);jm.add(m4);jm.add(m5);
    		JMenu jm2=new JMenu("程序");
    		 m2=new JMenuItem("终止");//创建菜单项
    		jm2.add(m2);
    //		jm.remove(mil2);//删除指定的菜单项
    		mb.add(jm);
    		mb.add(jm2);
    		m1.addActionListener(this);
    		m2.addActionListener(this);
    		m3.addActionListener(this);
    		m4.addActionListener(this);
    		m5.addActionListener(this);
    		 jt1=new JTextField(10);
    		 jt2=new JTextField(10);
    		 jt3=new JTextField(10);
    		JPanel jp=new JPanel(new GridLayout(3,2));
    		jp.add(new JLabel("数值一:"));
    		jp.add(jt1);
    		jp.add(new JLabel("数值二:"));
    		jp.add(jt2);
    		jp.add(new JLabel("运算结果:"));
    		jp.add(jt3);
    		add(jp);
    		this.setJMenuBar(mb);//设置菜单栏
    }
    	public void actionPerformed(ActionEvent e){
    		if(e.getSource()== m2){
    			System.exit(0);
    		}else{
    			Double num1=new Double(jt1.getText());
    			Double num2=new Double(jt2.getText());
    			Double num3= (double) 0;
    			if(e.getSource()==m1){
    				num3=num1+num2;
    			}
    			else if(e.getSource()==m3){
    				num3=num1-num2;
    			}
    			else if(e.getSource()==m4){
    				num3=num1*num2;
    			}
    			else if(e.getSource()==m5){
    				num3=num1/num2;
    			}
    			jt3.setText(new Double(num3).toString());
    		}
    	}
    	
    
    }

package com.util.ljc;
    
    import javax.swing.JFrame;
    
    public class test {
    
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		Meau m=new Meau();
    		m.setTitle("四则运算");
    		m.setSize(250, 180);
    		m.setLocation(350, 250);
    		m.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    		m.setVisible(true);
    
    	}
    
    }

运行效果：

![70][]![70 1][]![70 2][]

[70]: https://img-blog.csdn.net/20180811114258320?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdWp1Y2Fp/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70
[70 1]: https://img-blog.csdn.net/20180811114323711?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdWp1Y2Fp/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70
[70 2]: /images/20220517/cde70df46ce446fd85fab1424a05b776.png