使用小程序单击按钮时是否打印图像？

Question

So I need to display images when the button is clicked upon. When I click on the button it displays nothing. Is it possible to pass a parameter into void paint method so that I can check the condition using if condition? If square button is clicked it should print square and if circle button is clicked it should print circle

import java.applet.Applet;
import java.awt.Button;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;


public class Jungle extends Applet implements ActionListener{
    Button n;
    Button o;
    public void init()

    {
        n=new Button("Square");
        add(n);
        n.addActionListener(this);
         o = new Button("circle");
        add(o);
        o.addActionListener(this);



    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if(e.getSource()==n)
        {
            repaint();
        };


    }
    class Delta
    {
        void graphics(Graphics g)
        {
            g.drawRect(40, 40, 20, 20);
            g.fillRect(40, 40, 20, 20);
        }
    }

}

Answer 1

..so that I can check the condition using if condition..

Declare an image as a class attribute and set its value to null :

Image img = null;

When the button is clicked, set the image to equal the image to display.

In the paint(Graphics) method, check for null before painting the image. EG:

if (img!=null) {
    g.drawImage(img, 0, 0, this);
}