我有一个程序可以创建 2 个面板，然后在其中放置一个标签和两个按钮。标签设置为不可见setVisible(false)，然后添加两个按钮并打包框架。当我单击第一个按钮时，显示标签，，第二setVisible(true)个按钮再次隐藏它，setVisible(false)。当我单击每个按钮时，它们会移动以在标签隐藏时填充标签的空间，然后再次移动以避开显示的标签。我想阻止这种情况发生，即使标签被隐藏也让按钮保持在同一个地方。
这是代码：
public class MainFrame extends JFrame{
public JLabel statusLabel;
public JButton show;
public JButton hide;
public MainFrame(){
super("MagicLabel");
JPanel topPanel = new JPanel(); //Create Top Panel
statusLabel = new JLabel(""); //Init label
statusLabel.setVisible(false); //Hide label at startup
topPanel.setSize(400, 150); //Set the size of the panel, Doesn't work
topPanel.add(statusLabel); //Add label to panel
JPanel middlePanel = new JPanel(); //Create Middle Panel
show= new JButton("Show"); //Create show button
hide= new JButton("Hide"); //Create hide button
middlePanel.setSize(400, 50); //Set the size of the panel, Doesn't work
middlePanel.add(show); //Add show button
middlePanel.add(hide); //Add hide button
this.add(topPanel, "North"); //Add Top Panel to North
this.add(middlePanel, "Center"); //Add Middle Panel to Center
addActionListeners(); //void:adds action listeners to buttons
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setBounds(100, 100, 512, 400);
this.setPreferredSize(new Dimension(400,200)); //Set size of frame, Does work
this.pack();
this.setVisible(true);
}
public void animateInstall(boolean var0){ //Void to show and hide label from action listeners
statusLabel.setVisible(var0);
sendWorkingMessage("Boo!");
}
public void sendWorkingMessage(String message){ //Void to set text of label
this.statusLabel.setForeground(new Color(225, 225, 0));
this.statusLabel.setText(message);
}
void addActionListeners(){
show.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
animateInstall(true);
}
});
hide.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
animateInstall(false);
}
});
}