java - 单击 JButton 时显示图像

Question

我试图在单击 JButton 时显示图像，但在执行时单击按钮时不显示图像。

    import javax.swing.JButton;
import javax.swing.JFrame;
import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Graphics;
import java.awt.Image;
import javax.swing.ImageIcon;
import javax.swing.JApplet;
import java.awt.*;

public class new2 extends JFrame implements ActionListener
{
private boolean b1,b2;  

Container contentPane= getContentPane();
JButton awar=new JButton("@war");
JButton arrow=new JButton("arrow");
private Image image1,image2;

public new2()
    {
    setSize(400, 300);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        contentPane.setLayout(new FlowLayout());

        awar.addActionListener(this);
        contentPane.add(awar).setVisible(true);

        arrow.addActionListener(this);
        contentPane.add(arrow).setVisible(true);

        }

public void init()
    {


    image1=Toolkit.getDefaultToolkit().getImage("@war.jpeg");
    image2=Toolkit.getDefaultToolkit().getImage("arrow.gif");
    }


public void paint(Graphics g)
{

    if(b1==true)
    {
    g.drawImage(image1,0,0,this);
    }
    else if(b2==true)
    {
    g.drawImage(image2,0,0,this);
    }

}

public void actionPerformed(ActionEvent event)
{

        String actionCommand = event.getActionCommand();

    if(actionCommand.equals("@war"))
    {
    b1=true;
    }
    else if(actionCommand.equals("arrow"))
    {
    b2=true;
    }
}

public static void main(String args[])
{
new2 m=new new2();
m.setVisible(true);
}

Answer 1

..display an image upon clicking a JButton but upon execution the image is not displayed when button is clicked.

使用 JToggleButton 如图所示 here .