JPanel存在问题。 这是一个CardLayout和两个更改的子面板。 我需要做一个从子面板1切换到2并显示所选产品的按钮。
问题： 当我选择产品卡时，JPanel会更改，但它为空白。 如果我使用鼠标跨过窗口，则会显示按钮，但不会显示JLabels。 如果我调整窗口的大小，它又是空的。 有什么问题吗？
编辑： 这里的代码返回相同的错误。
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.event.*;
import javax.swing.*;
public class MainFrame extends JFrame {
private static final long serialVersionUID = 1L;
// private String title;
// private Dimension d;
public MainFrame(String title, Dimension d) {
// LoginPanel template = new LoginPanel(this);
// RegisterPanel template = new RegisterPanel(this);
CustomerPanel template = new CustomerPanel(this);
this.setTitle(title);
this.setSize(d);
this.setVisible(true);
this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
this.getContentPane().add(template);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
new MainFrame("Fubars", new Dimension(800, 650));
});
}
}
@SuppressWarnings("serial")
class CustomerPanel extends JPanel {
MainFrame mf;
JPanel one, two;
JPanel panel;
public CustomerPanel(MainFrame mf) {
this.mf = mf;
mf.getContentPane().setLayout(new CardLayout(0, 0));
JPanel container = new JPanel();
mf.getContentPane().add(container, "name_36743208542992");
container.setLayout(new BorderLayout(0, 0));
JPanel back = new JPanel();
container.add(back, BorderLayout.NORTH);
back.setLayout(new FlowLayout(FlowLayout.LEFT));
JButton btnControl = new JButton("<");
back.add(btnControl);
panel = new JPanel();
container.add(panel, BorderLayout.CENTER);
CardLayout cl = new CardLayout(0, 0);
panel.setLayout(cl);
one = new OnePanel(this.mf);
two = new JPanel();
panel.add(one, "1");
panel.add(two, "2");
btnControl.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
two = new LoginPanel(mf);
cl.next(panel);
}
});
}
}
@SuppressWarnings("serial")
class LoginPanel extends JPanel {
// private MainFrame mf;
private JTextField textField;
private JPasswordField passwordField;
public LoginPanel(MainFrame mf) {
// this.mf = mf;
mf.getContentPane().setLayout(new BorderLayout(0, 0));
JPanel panel = new JPanel();
mf.getContentPane().add(panel, BorderLayout.CENTER);
GridBagLayout gbl_panel = new GridBagLayout();
gbl_panel.columnWidths = new int[] { 100, 55, 72, 171, 0 };
gbl_panel.rowHeights = new int[] { 69, 22, 22, 0 };
gbl_panel.columnWeights = new double[] { 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE };
gbl_panel.rowWeights = new double[] { 0.0, 0.0, 0.0, Double.MIN_VALUE };
panel.setLayout(gbl_panel);
JLabel lblNewLabel = new JLabel("Email");
GridBagConstraints gbc_lblNewLabel = new GridBagConstraints();
gbc_lblNewLabel.fill = GridBagConstraints.HORIZONTAL;
gbc_lblNewLabel.insets = new Insets(0, 0, 5, 5);
gbc_lblNewLabel.gridx = 1;
gbc_lblNewLabel.gridy = 1;
panel.add(lblNewLabel, gbc_lblNewLabel);
textField = new JTextField();
GridBagConstraints gbc_textField = new GridBagConstraints();
gbc_textField.anchor = GridBagConstraints.NORTH;
gbc_textField.insets = new Insets(0, 0, 5, 0);
gbc_textField.gridx = 3;
gbc_textField.gridy = 1;
panel.add(textField, gbc_textField);
textField.setColumns(15);
JLabel lblNewLabel_1 = new JLabel("Password");
GridBagConstraints gbc_lblNewLabel_1 = new GridBagConstraints();
gbc_lblNewLabel_1.anchor = GridBagConstraints.WEST;
gbc_lblNewLabel_1.insets = new Insets(0, 0, 0, 5);
gbc_lblNewLabel_1.gridx = 1;
gbc_lblNewLabel_1.gridy = 2;
panel.add(lblNewLabel_1, gbc_lblNewLabel_1);
passwordField = new JPasswordField();
passwordField.setColumns(15);
GridBagConstraints gbc_passwordField = new GridBagConstraints();
gbc_passwordField.anchor = GridBagConstraints.NORTH;
gbc_passwordField.gridx = 3;
gbc_passwordField.gridy = 2;
panel.add(passwordField, gbc_passwordField);
JPanel panel_1 = new JPanel();
mf.getContentPane().add(panel_1, BorderLayout.SOUTH);
panel_1.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 30));
JButton btnNewButton = new JButton("LOGIN");
panel_1.add(btnNewButton);
btnNewButton.setActionCommand("login");
JButton btnRegistration = new JButton("REGISTER");
panel_1.add(btnRegistration);
btnRegistration.setActionCommand("registration");
}
}
@SuppressWarnings("serial")
class OnePanel extends JPanel {
// private MainFrame mf;
public OnePanel(MainFrame mf) {
// this.mf = mf;
mf.getContentPane().setLayout(new CardLayout(0, 0));
JPanel container = new JPanel();
mf.getContentPane().add(container, "name_36743208542992");
container.setLayout(new BorderLayout(0, 0));
JPanel image = new JPanel();
container.add(image, BorderLayout.CENTER);
JButton btnImageBack = new JButton("<");
image.add(btnImageBack);
JLabel imageContainer = new JLabel("Images");
image.add(imageContainer);
imageContainer.setBounds(new Rectangle(100, 100, 100, 100));
imageContainer.setHorizontalTextPosition(SwingConstants.CENTER);
imageContainer.setHorizontalAlignment(SwingConstants.CENTER);
imageContainer.setAlignmentX(Component.CENTER_ALIGNMENT);
imageContainer.setIconTextGap(3);
imageContainer.setIcon(null);
JButton btnImageForward = new JButton(">");
image.add(btnImageForward);
btnImageForward.setAlignmentY(Component.BOTTOM_ALIGNMENT);
btnImageForward.setAlignmentX(Component.CENTER_ALIGNMENT);
JPanel info = new JPanel();
container.add(info, BorderLayout.EAST);
GridBagLayout gbl_info = new GridBagLayout();
gbl_info.columnWidths = new int[] { 0, 0, 63, 0, 0, 0 };
gbl_info.rowHeights = new int[] { 0, 0, 25, 0, 0, 0, 0 };
gbl_info.columnWeights = new double[] { 1.0, 0.0, 1.0, 0.0, 1.0, Double.MIN_VALUE };
gbl_info.rowWeights = new double[] { 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, Double.MIN_VALUE };
info.setLayout(gbl_info);
JLabel lblTitle = new JLabel("Title");
GridBagConstraints gbc_lblTitle = new GridBagConstraints();
gbc_lblTitle.anchor = GridBagConstraints.NORTHWEST;
gbc_lblTitle.insets = new Insets(0, 0, 5, 5);
gbc_lblTitle.gridx = 2;
gbc_lblTitle.gridy = 1;
info.add(lblTitle, gbc_lblTitle);
JLabel lblDescription = new JLabel("Description");
GridBagConstraints gbc_lblDescription = new GridBagConstraints();
gbc_lblDescription.anchor = GridBagConstraints.WEST;
gbc_lblDescription.insets = new Insets(0, 0, 5, 5);
gbc_lblDescription.gridx = 2;
gbc_lblDescription.gridy = 2;
info.add(lblDescription, gbc_lblDescription);
JLabel lblPrice = new JLabel("Price");
GridBagConstraints gbc_lblPrice = new GridBagConstraints();
gbc_lblPrice.anchor = GridBagConstraints.WEST;
gbc_lblPrice.insets = new Insets(0, 0, 5, 5);
gbc_lblPrice.gridx = 2;
gbc_lblPrice.gridy = 3;
info.add(lblPrice, gbc_lblPrice);
lblPrice.setToolTipText("Price");
JButton btnAddCart = new JButton("Add to Cart");
GridBagConstraints gbc_btnAddCart = new GridBagConstraints();
gbc_btnAddCart.insets = new Insets(0, 0, 5, 5);
gbc_btnAddCart.anchor = GridBagConstraints.WEST;
gbc_btnAddCart.gridx = 2;
gbc_btnAddCart.gridy = 4;
info.add(btnAddCart, gbc_btnAddCart);
}
}