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

..这样我就可以使用条件来检查条件..

将图像声明为类属性，并将其值设置为null：

Image img = null;

单击该按钮时，将图像设置为等于要显示的图像。

在paint(Graphics)方法中，在绘制图像之前检查null。 E.G：

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

Printing images when a Button is clicked using Applets?

1 个答案: