我是新來的佈局和我現在使用的是一個CardLayout與兩個不同的卡,目前有一個背景圖像和一個按鈕。如下所示,該按鈕位於屏幕的頂部,我想將它放置在靠近底部的某個位置。我的理解是GridBagLayout將是實現這一目標的最佳方式。所以我的第一個問題是,這是真的嗎?另外,如果我想將GridBagLayout放在CardLayout中的卡上,那麼是否可以這樣做。我想在GridBagLayout中添加許多其他對象(如果這是實現它的最好方法,並且如果可能的話),因爲我會進一步深入該項目,因此有關正確方向的任何建議都將不勝感激。Java可以使用GridBagLayout來組織CardLayout中使用的JPanel
import java.awt.*;
import java.awt.event.*;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.*;
public class Cards implements ActionListener {
private JPanel cards;
private JButton button1;
private JButton button2;
private Image backgroundImage;
public void addComponentToPane(Container pane) throws IOException {
try {
backgroundImage = ImageIO.read(getClass().getResource("resources/background.jpg"));
} catch (IOException ex) {
ex.printStackTrace(System.err);
}
//create cards
JPanel card1 = new JPanel()
{
@Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawImage(backgroundImage, 0, 0, null);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(
backgroundImage.getWidth(null),
backgroundImage.getHeight(null));
}
};
JPanel card2 = new JPanel()
{
@Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawImage(backgroundImage, 0, 0, null);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(
backgroundImage.getWidth(null),
backgroundImage.getHeight(null));
}
};
//create buttons
button1 = new JButton("Button 1");
button2 = new JButton("Button 2");
button1.addActionListener(this);
button2.addActionListener(this);
//add buttons to cards
card1.add(button1);
card2.add(button2);
//create panel that contains cards
cards = new JPanel(new CardLayout());
cards.add(card1, "Card 1");
cards.add(card2, "Card 2");
pane.add(cards, BorderLayout.SOUTH);
}
public void itemStateChanged(ItemEvent evt) {
CardLayout cl = (CardLayout)(cards.getLayout());
cl.show(cards, (String)evt.getItem());
}
public static void createAndShowGUI() throws IOException {
//create and setup window
JFrame frame = new JFrame("Frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//create and setup content pane
Cards main = new Cards();
main.addComponentToPane(frame.getContentPane());
//display window
frame.pack();
//frame.setResizable(false);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent ae) {
if (ae.getSource() == button1) {
CardLayout cl = (CardLayout) (cards.getLayout());
cl.show(cards, "Card 2");
} else if (ae.getSource() == button2) {
CardLayout cl = (CardLayout) (cards.getLayout());
cl.show(cards, "Card 1");
}
}
public static void main(String[] args) {
//set look and feel
try {
UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
} catch (UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
} catch (IllegalAccessException ex) {
ex.printStackTrace();
} catch (InstantiationException ex) {
ex.printStackTrace();
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
//schedule job for the event dispatch thread creating and showing GUI
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
createAndShowGUI();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
}