GridBagLayout
コンポーネントをコンテナの中心にレイアウトします。これは、(そして時には煩わしい) デフォルト機能です。
空の「フィラー」コンポーネント ( a など) をコンテナ内の他のコンポーネントのすぐ下の位置に と で追加してJLabel
みてGridBagConstraints
くださいweightx=1
。weighty=1
これにより、コンテナの左上隅に強制的に配置されます...
更新しました...
中央揃え/デフォルト...
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class GridBagLayoutTest {
public static void main(String[] args) {
new GridBagLayoutTest();
}
public GridBagLayoutTest() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.setSize(600, 600);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
JLabel picture = new JLabel();
try {
picture.setIcon(new ImageIcon(ImageIO.read(new File("/path/to/your/picture"))));
} catch (IOException ex) {
ex.printStackTrace();
picture.setText("Bad picture");
}
add(picture, gbc);
}
}
}
整列...
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class GridBagLayoutTest {
public static void main(String[] args) {
new GridBagLayoutTest();
}
public GridBagLayoutTest() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.setSize(600, 600);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
JLabel picture = new JLabel();
try {
picture.setIcon(new ImageIcon(ImageIO.read(new File("/path/to/your/picture"))));
} catch (IOException ex) {
ex.printStackTrace();
picture.setText("Bad picture");
}
add(picture, gbc);
JLabel filler = new JLabel();
gbc.gridx = 1;
gbc.gridy = 1;
gbc.weightx = 1;
gbc.weighty = 1;
add(filler, gbc);
}
}
}