Computer Science

import javax.swing.*;

import java.awt.event.*;

public class MyFrame extends JFrame implements ActionListener

{

    private JPanel panel;

    private JButton b1;

    private JButton b2;

    private JLabel l1;

    private JTextField t1;

    private JTextField t2;

    public MyFrame()

    {       

         this.setSize(300, 150);

         this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

         this.setTitle("연습~");

         panel = new JPanel();

         b1 = new JButton("원의 둘레");

         b2 = new JButton("원의 면적");

         l1 = new JLabel("반지름의 길이를 입력해주세요:");

         t1 = new JTextField(5);

         t2 = new JTextField(10);        

         b1.addActionListener(this); //현재 객체를 리스너로 등록하였다.

         b2.addActionListener(this);        

         panel.add(l1);

         panel.add(t1);

         panel.add(b1);

         panel.add(b2);

         panel.add(t2);

         this.add(panel);

         this.setVisible(true);

    }    

    public void actionPerformed(ActionEvent e)

    {

        double d;

        if(e.getSource()==b1)

        {

            d = Double.parseDouble(t1.getText());

            t2.setText(Double.toString(d *3.14));

        }

        else if(e.getSource()==b2)

        {

            d = Double.parseDouble(t1.getText());

            t2.setText(Double.toString(d *d * 3.14));

        }

    }

}

public class MyFrame extends JFrame

{

    private JPanel panel;

    private JButton b1;

    private JButton b2;

    private JLabel l1;

    private JTextField t1;

    private JTextField t2;

    public MyFrame()

    {       

         this.setSize(300, 150);

         this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

         this.setTitle("연습~");

         panel = new JPanel();

         b1 = new JButton("원의 둘레");

         b2 = new JButton("원의 면적");

         l1 = new JLabel("반지름의 길이를 입력해주세요:");

         t1 = new JTextField(5);

         t2 = new JTextField(10);        

         b1.addActionListener(new MyActionHandler());

         b2.addActionListener(new MyActionHandler());        

         panel.add(l1);

         panel.add(t1);

         panel.add(b1);

         panel.add(b2);

         panel.add(t2);

         this.add(panel);

         this.setVisible(true);

    }

    Private class MyActionHandler  implements ActionListener
{       

    public void actionPerformed(ActionEvent e)

    {

        double d;

        if(e.getSource()==b1)

        {

            d = Double.parseDouble(t1.getText());

            t2.setText(Double.toString(d *3.14));

        }

        else if(e.getSource()==b2)

        {

            d = Double.parseDouble(t1.getText());

            t2.setText(Double.toString(d *d * 3.14));

        }

    }

}

}

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

public class MyActionHandler  implements ActionListener //액션인터페이스를 사용

{

    private MyFrame f;  

    public MyActionHandler(MyFrame f) //포인터로 MyFrame클래스를 가져온다.

    {

        this.f = f;

    }   

    public void actionPerformed(ActionEvent e)

    {

        double d;       

        if(e.getSource()==f.getButton())

        {

            d = Double.parseDouble(f.getTextField());

            f.setTextField(d *3.14);

        }

        else if(e.getSource()==f.getButton2())

        {

            d = Double.parseDouble(f.getTextField());

            f.setTextField(d*d*3.14);

        }

    }   

}

import javax.swing.*;

public class MyFrame extends JFrame //JFrame을 상속받는다.

{

    private JPanel panel;

    private JButton b1;

    private JButton b2;

    private JLabel l1;

    private JTextField t1;

    private JTextField t2;

    public JButton getButton(){ //MyFrame의 private 변수로 인해 get set 함수만들기

            return b1;

        }       

    public JButton getButton2(){

            return b2;

        }       

    public String getTextField(){

            return t1.getText();

        }   

    public void setTextField(Double d){

            t2.setText(Double.toString(d));

    }     

    public MyFrame()

    {       

         setSize(300, 150);

         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

         setTitle("연습~");

         panel = new JPanel();

         b1 = new JButton("원의 둘레");

         b2 = new JButton("원의 면적");

         l1 = new JLabel("반지름의 길이를 입력해주세요:");

         t1 = new JTextField(5);

         t2 = new JTextField(10);        

         MyActionHandler han = new MyActionHandler(this); //리스너클래스 생성

         b1.addActionListener(han); //리스너등록

         b2.addActionListener(han);        

         panel.add(l1);

         panel.add(t1);

         panel.add(b1);

         panel.add(b2);

         panel.add(t2);

         add(panel);

         setVisible(true);

    }    

}

public class MyFrameTest

{

    public static void main(String[] args)

    {

        MyFrame my = new MyFrame();

    }

}