how to paint images on clicking button in frame?

问题

I've made two buttons in frame .I want to know how to display different images on clicking different buttons? is there another way out or i have to make panel?I am at beginner stage

package prac;
import java.awt.*;
import java.awt.event.*;

public class b extends Frame implements ActionListener{
String msg;
Button one,two;

b()
{   setSize(1000,500);
    setVisible(true);
    setLayout(new FlowLayout(FlowLayout.LEFT));
    one=new Button("1");
    two=new Button("2");

    add(one);
    add(two);

    one.addActionListener(this);
    two.addActionListener(this);

}
public void actionPerformed(ActionEvent e)
{
    msg=e.getActionCommand();
    if(msg.equals("1"))
    {
        msg="Pressed 1";
    }
    else
        msg="pressed 2";
repaint();      
}

public void paint(Graphics g)
{
    g.drawString(msg,100,300);
}
public static void main(String s[])
{
    new b();
}
}

回答1:

Use JLabel and change the icon when button is clicked.

Some points:

call setVisible(true) in the end after adding all the component.
use JFrame#pack() method that automatically fit the components in the JFrame based on component's preferred dimension instead of calling JFrame#setSize() method.

sample code:

final JLabel jlabel = new JLabel();
add(jlabel);

final Image image1 = ImageIO.read(new File("resources/1.png"));
final Image image2 = ImageIO.read(new File("resources/2.png"));

JPanel panel = new JPanel();
JButton jbutton1 = new JButton("Show first image");
jbutton1.addActionListener(new ActionListener() {

    @Override
    public void actionPerformed(ActionEvent arg0) {
        jlabel.setIcon(new ImageIcon(image1));
    }
});

JButton jbutton2 = new JButton("Show second image");
jbutton2.addActionListener(new ActionListener() {

    @Override
    public void actionPerformed(ActionEvent arg0) {
        jlabel.setIcon(new ImageIcon(image2));
    }
});

panel.add(jbutton1);
panel.add(jbutton2);
add(panel, BorderLayout.NORTH);

来源：https://stackoverflow.com/questions/24716597/how-to-paint-images-on-clicking-button-in-frame

标签

java

button

paint