我正在制作一个有两个面板的gui。首次加载gui时，只能看到一个面板，按下按钮时，将显示新面板。问题是，在第二个面板加载时，按钮是不可见的，只有当鼠标悬停在按钮上时才会显示。最重要的是，当你移动屏幕时，它们会再次变得不可见，需要悬停在上面再次显示。 我真的不知道该尝试什么，因为我已经看过有多个面板的方法，这似乎是最好的方法，而且这个按钮的实现方式与我为第一个面板实现它们的方式相同正确。
完整代码
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Gui {
private JFrame frame;
private JPanel panel1;
private JPanel panel2;
private JButton btnShip1, btnShip2, btnShip3, btnTutorial, btnLeftControl, btnHull, btnTargeting, btnRadar, btnWarning, btnRightControl;
private JTextField txtCharacterName, txtShipName;
private JLabel welcome, background;
public static void main(String[] args) {
new Gui();
}
public Gui(){
createWindow();
addButtons();
addFields();
addWelcome();
frame.add(panel1);
frame.setVisible(true);
addBackground();
addShipControls();
}
public void createWindow(){
frame = new JFrame();
frame.setTitle("Space Battle");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(642, 518);
panel1 = new JPanel();
panel1.setLayout(null);
panel1.setBackground(Color.decode("#242627"));
panel2 = new JPanel();
panel2.setLayout(null);
panel2.setBackground(Color.decode("#242627"));
}
public void addButtons(){
btnShip1 = new JButton ();
try
{
ImageIcon img = new ImageIcon ("resources/cruiserSelectBtn.jpg");
btnShip1.setIcon(img);
}
catch (Exception e) {}
try
{
ImageIcon img = new ImageIcon ("resources/button_1_hover.gif");
btnShip1.setRolloverIcon(img);
}
catch (Exception e) {}
btnShip1.setBounds(246,0,380,160);
btnShip1.setMargin(new Insets(0, 0, 0, 0));
btnShip1.addActionListener(new cruiserSelectHandler());
btnShip1.setBorder(null);
panel1.add (btnShip1);
btnShip2 = new JButton ();
try
{
ImageIcon img = new ImageIcon ("resources/fighterSelectBtn.jpg");
btnShip2.setIcon(img);
}
catch (Exception e) {}
try
{
ImageIcon img = new ImageIcon ("resources/button_2_hover.gif");
btnShip2.setRolloverIcon(img);
}
catch (Exception e) {}
btnShip2.setBounds(246,160,380,160);
btnShip2.setMargin(new Insets(0, 0, 0, 0));
btnShip2.addActionListener(new fighterSelectHandler());
btnShip2.setBorder(null);
panel1.add (btnShip2);
btnShip3 = new JButton ();
try
{
ImageIcon img = new ImageIcon ("resources/battleSelectBtn.jpg");
btnShip3.setIcon(img);
}
catch (Exception e) {}
try
{
ImageIcon img = new ImageIcon ("resources/button_3_hover.gif");
btnShip3.setRolloverIcon(img);
}
catch (Exception e) {}
btnShip3.setBounds(246,320,380,160);
btnShip3.setMargin(new Insets(0, 0, 0, 0));
btnShip3.addActionListener(new battleSelectHandler());
btnShip3.setBorder(null);
panel1.add (btnShip3);
btnTutorial = new JButton ();
try
{
ImageIcon img = new ImageIcon ("resources/tutorialBtn.jpg");
btnTutorial.setIcon(img);
}
catch (Exception e) {}
btnTutorial.setBounds(5,426,234,49);
btnTutorial.setMargin(new Insets(0, 0, 0, 0));
panel1.add (btnTutorial);
}
public void addFields(){
txtCharacterName = new JTextField("Insert Character Name");
txtCharacterName.setBounds(12,260,220,35);
panel1.add(txtCharacterName);
txtShipName = new JTextField("Insert Ship Name");
txtShipName.setBounds(12,315,220,35);
panel1.add(txtShipName);
}
public void addWelcome(){
welcome = new JLabel ();
try
{
ImageIcon img = new ImageIcon ("resources/welcome.jpg");
welcome.setIcon(img);
}
catch (Exception e) {}
welcome.setBounds(0,0,247,229);
panel1.add(welcome);
}
//Class used to change panels
class cruiserSelectHandler implements ActionListener {
public void actionPerformed(ActionEvent even) {
frame.add(panel2);
panel1.setVisible(false);
}
}
class fighterSelectHandler implements ActionListener {
public void actionPerformed(ActionEvent even) {
frame.add(panel2);
panel1.setVisible(false);
}
}
class battleSelectHandler implements ActionListener {
public void actionPerformed(ActionEvent even) {
frame.add(panel2);
panel1.setVisible(false);
}
}
public void addBackground(){
//Is the background interfering?
background = new JLabel ();
try
{
ImageIcon img = new ImageIcon ("resources/background.jpg");
background.setIcon(img);
}
catch (Exception e) {}
background.setBounds(0,0,640,480);
panel2.add(background);
}
//Class used to add controls/buttons
public void addShipControls(){
btnLeftControl = new JButton ();
try
{
ImageIcon img = new ImageIcon ("resources/left_controls.png");
btnLeftControl.setIcon(img);
}
catch (Exception e) {}
btnLeftControl.setBounds(-8,319,131,160);
btnLeftControl.setMargin(new Insets(0, 0, 0, 0));
btnLeftControl.setBorder(null);
panel2.add (btnLeftControl);
btnHull = new JButton ();
try
{
ImageIcon img = new ImageIcon ("resources/hull_controls.png");
btnHull.setIcon(img);
}
catch (Exception e) {}
btnHull.setBounds(123,319,91,160);
btnHull.setMargin(new Insets(0, 0, 0, 0));
btnHull.setBorder(null);
panel2.add (btnHull);
btnTargeting = new JButton ();
try
{
ImageIcon img = new ImageIcon ("resources/targeting_controls.png");
btnTargeting.setIcon(img);
}
catch (Exception e) {}
btnTargeting.setBounds(214,319,202,160);
btnTargeting.setMargin(new Insets(0, 0, 0, 0));
btnTargeting.setBorder(null);
panel2.add (btnTargeting);
btnWarning = new JButton ();
try
{
ImageIcon img = new ImageIcon ("resources/warning_controls.png");
btnWarning.setIcon(img);
}
catch (Exception e) {}
btnWarning.setBounds(416,411,86,68);
btnWarning.setMargin(new Insets(0, 0, 0, 0));
btnWarning.setBorder(null);
panel2.add (btnWarning);
btnRadar = new JButton ();
try
{
ImageIcon img = new ImageIcon ("resources/radar_idea.gif");
btnRadar.setIcon(img);
}
catch (Exception e) {}
btnRadar.setBounds(416,319,86,92);
btnRadar.setMargin(new Insets(0, 0, 0, 0));
btnRadar.setBorder(null);
panel2.add (btnRadar);
btnRightControl = new JButton ();
try
{
ImageIcon img = new ImageIcon ("resources/right_controls.png");
btnRightControl.setIcon(img);
}
catch (Exception e) {}
btnRightControl.setBounds(502,319,131,160);
btnRightControl.setMargin(new Insets(0, 0, 0, 0));
btnRightControl.setBorder(null);
panel2.add (btnRightControl);
}
}
答案 0 :(得分：3)
按下按钮时，将显示新面板。
问题是：
默认情况下，Swing按照添加它们的相反顺序绘制组件。
因此，当您添加panel1时，它是框架的唯一面板，因此它被绘制。
然后单击按钮并添加panel2。因此，Swing绘制了panel2，然后将panel1重新绘制在顶部，因此panel2被隐藏。当您将鼠标悬停在按钮上时，它会显示，因为按钮会侦听mouseEntered事件，并且按钮会重新绘制。
当您调整屏幕大小时，面板2被绘制，然后panel1被绘制，因此您再次遇到问题。
解决方案是使用适当的布局管理器。在您的情况下，您应该使用卡布局。卡片布局将交换面板，确保一次只能看到一个面板。阅读Using Card Layout上的Swing教程。然后摆脱所有的null布局和setBounds（）方法。