j_combobox.java

来自「可进行整型和浮点型的四则运算」· Java 代码 · 共 113 行

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class J_ComboBox extends JFrame {
    private JTextField[] m_textField= {
        new JTextField(10),new JTextField(10),new JTextField(10)
    };
    private JButton m_button=new JButton("=");
    private String m_items[]={"+","-","*","/"};
    private JComboBox m_comboBox=new JComboBox(m_items);
    private JRadioButton[] m_radio={new JRadioButton("整数运算"),new JRadioButton("浮点运算")};
    public J_ComboBox() {
        super("JComboBox");
        Container container=getContentPane();
        container.setLayout(new FlowLayout());
        
        
        
        container.add(m_textField[0]);
        //container.add(m_button[0]);
        container.add(m_comboBox);
        container.add(m_textField[1]);
        container.add(m_button);
        container.add(m_textField[2]);
        container.add(m_radio[0]);
        container.add(m_radio[1]);
        
        J_Handler handler=new J_Handler();
        m_textField[0].addActionListener(handler);
        m_textField[1].addActionListener(handler);
        m_textField[2].addActionListener(handler);
        m_button.addActionListener(handler);
        m_comboBox.addActionListener(handler);
        
        ButtonGroup radioGroup=new ButtonGroup();
        radioGroup.add(m_radio[0]);
        radioGroup.add(m_radio[1]);
        
        m_radio[0].setSelected(true);
        m_radio[1].setSelected(false);
        
        setSize(500,150);
        setVisible(true);
    }
    
    
    private class J_Handler implements ActionListener {
        
        public void actionPerformed(ActionEvent event) {
            String s1=m_textField[0].getText();
            String s2=m_textField[1].getText();
            if(m_radio[0].isSelected()) {
                int a=Integer.parseInt(s1);
                int b=Integer.parseInt(s2);
                int c=0;
                if(event.getSource()==m_button) {
                    if(m_comboBox.getSelectedIndex()==0)
                        
                        c=a+b;
                    
                    else if(m_comboBox.getSelectedIndex()==1)
                        
                        c=a-b;
                    
                    else if(m_comboBox.getSelectedIndex()==2)
                        
                        c=a*b;
                    
                    else if(m_comboBox.getSelectedIndex()==3)
                        
                        c=a/b;
                    
                    m_textField[2].setText(""+c);
                }
            }
            else if(m_radio[1].isSelected()) {
                float aa=Float.parseFloat(s1);
                float bb=Float.parseFloat(s2);
                float cc=0;
                if(event.getSource()==m_button) {
                    if(m_comboBox.getSelectedIndex()==0)
                        
                        cc=aa+bb;
                    
                    else if(m_comboBox.getSelectedIndex()==1)
                        
                        cc=aa-bb;
                    
                    else if(m_comboBox.getSelectedIndex()==2)
                        
                        cc=aa*bb;
                    
                    else if(m_comboBox.getSelectedIndex()==3)
                        
                        cc=aa/bb;
                    
                    m_textField[2].setText(""+cc);
                }
                
            }
        }
    }
    
    
    
    public static void main(String args[]) {
        J_ComboBox application=new J_ComboBox();
        application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
    }
}