electronic.java

java课后题的详细答案

//package elec;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class electronic {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		jframe f = new jframe();
		f.setVisible(true);
		f.setLocation(300, 200);
		f.setSize(300, 300);
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}

}
class jframe extends JFrame implements ActionListener{
	/**
	 * 
	 */
	JButton[] number_button = new JButton[10];
	JButton[] operator_button = new JButton[6]; 
	JPanel panel_text = new JPanel();
	JPanel panel_number = new JPanel();
	JPanel panel_operator = new JPanel();
	JTextField text = new JTextField("计算区域");
	JTextField text0 = new JTextField("输出区域");
	String cho ="" ;
	String chn ="" ;
	jframe(){
		super("简单计算器的应用");
		getContentPane().setLayout(new BorderLayout(3,3));

		panel_text.setLayout(new BorderLayout(5,5));
		panel_number.setLayout(new GridLayout(4,3));
		panel_operator.setLayout(new GridLayout(4,3));
		for(int i = 0 ; i <= 9 ; i++ ){
			number_button[i] = new JButton("" + i);
			number_button[i].addActionListener(this);
		}
		for(int i = 0 ; i <= 9 ; i++ ){
			panel_number.add(number_button[i]);
		}
		
		operator_button[0] = new JButton("+");
		operator_button[1] = new JButton("-");
		operator_button[2] = new JButton("*");
		operator_button[3] = new JButton("/");
		operator_button[4] = new JButton("计算");
		operator_button[5] = new JButton("清空");
		
		for(int i = 0 ; i <= 5; i++ ){
			panel_operator.add(operator_button[i]);
		}
		
		panel_text.add(text,BorderLayout.NORTH);
		panel_text.add(text0,BorderLayout.CENTER);
		panel_number.setBackground(Color.cyan);
		panel_operator.setBackground(Color.cyan);
		getContentPane().add(panel_text,BorderLayout.NORTH);
		getContentPane().add(panel_number,BorderLayout.CENTER);
		getContentPane().add(panel_operator, BorderLayout.EAST);
		operator_button[0].addActionListener(this);
		operator_button[1].addActionListener(this);
		operator_button[2].addActionListener(this);
		operator_button[3].addActionListener(this);
		operator_button[4].addActionListener(this);
		operator_button[5].addActionListener(this);

	}

	@Override
	public void actionPerformed(ActionEvent e) {
		// TODO Auto-generated method stub
		if(e.getSource() == operator_button[0]){
			//JOptionPane.showMessageDialog(null, "OK");
			cho = operator_button[0].getText();
			text.setText(cho);
		}
		if(e.getSource() == operator_button[1]){

			cho = cho + operator_button[1].getText();
			text.setText(cho);
		}
		if(e.getSource() == operator_button[2]){

			cho = cho + operator_button[2].getText();
			text.setText(cho);
		}
		if(e.getSource() == operator_button[3]){

			cho = cho + operator_button[3].getText();
			text.setText(cho);
		}
		if(e.getSource() == operator_button[4]){

			String fg = text.getText();
			text0.setText(fg);
		}
		if(e.getSource() == operator_button[5]){

			text.setText("");
			text0.setText("");
			cho = "";
			chn = "";
		}
		/*----------------------------------------------------------*/
		if(e.getSource() == number_button[0]){

			chn = chn + number_button[0].getText();
			text.setText(chn);
		}
		if(e.getSource() == number_button[1]){

			chn = chn + number_button[1].getText();
			text.setText(chn);
		}
		if(e.getSource() == number_button[2]){

			chn = chn + number_button[2].getText();
			text.setText(chn);
		}
		if(e.getSource() == number_button[3]){

			chn = chn + number_button[3].getText();
			text.setText(chn);
		}
		if(e.getSource() == number_button[4]){

			chn = chn + number_button[4].getText();
			text.setText(chn);
		}
		if(e.getSource() == number_button[5]){
			chn = chn + number_button[5].getText();
			text.setText(chn);
		}
		if(e.getSource() == number_button[6]){

			chn = chn + number_button[6].getText();
			text.setText(chn);
		}
		if(e.getSource() == number_button[7]){
			chn = chn + number_button[7].getText();
			text.setText(chn);
		}
		if(e.getSource() == number_button[8]){
			chn = chn + number_button[8].getText();
			text.setText(chn);
		}
		if(e.getSource() == number_button[9]){
			chn = chn + number_button[9].getText();
			text.setText(chn);
		}
	}
}