所以我的问题出在JComboBoxs和ActionListeners上。我将制作一个新的简化代码，以尝试从我的原始代码中表示问题。我想要一个JComboBox添加一个JComboBox，然后他将添加第三个JComboBox，依此类推。每次我单击它们时，我都希望它们根据以前的JComboBox显示的内容更改内容。
无论如何，我现在最大的问题是当我在第一个JComboBox“赛车盒”中选择某些东西时。它不仅将“infantrybox”添加到面板中，还添加了我拥有的所有其他JComboBox，而不是仅在我在各自的JComboBox中选择某些内容时才添加它们。
就像当我在赛车箱中选择某些东西时，它开始从其他每个动作中读取代码执行。
奇怪的是，在添加“racebox”之后，JComboBoxes是向后添加的。第一：赛马箱 第二：步兵箱 第三：步兵箱
...
public void Attacker(){
racebox = new JComboBox(array);
infantrybox = new JComboBox();
infantrynmrbox = new JComboBox();
panel.add(racebox);
panel.revalidate();
panel.repaint();
racebox.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
JComboBox cb = (JComboBox)e.getSource();
race = (String)cb.getSelectedItem();
infantrybox.removeAllItems();
for(String s : otherarray){
infantrybox.addItem(s);
}
panel.add(infantrybox);
panel.revalidate();
panel.repaint();
}
});
infantrybox.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
JComboBox cb = (JComboBox)e.getSource();
infantry = (String)cb.getSelectedItem();
infantrynmrbox.removeAllItems();
for(String s : nmr){
infantrynmrbox.addItem(s);
System.out.println(s + " ");
}
panel.add(infantrynmrbox);
panel.revalidate();
panel.repaint();
}
});
infantrynmrbox.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
JComboBox cb = (JComboBox)e.getSource();
infantrynmr = Integer.parseInt((String)cb.getSelectedItem());
}
});
...
}
不要继续向面板添加组合框。
相反，您只需更改现有组合框的模型。
例如：
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.plaf.basic.*;
public class ComboBoxTwo extends JPanel implements ActionListener
{
private JComboBox<String> mainComboBox;
private JComboBox<String> subComboBox;
private Hashtable<String, String[]> subItems = new Hashtable<String, String[]>();
public ComboBoxTwo()
{
String[] items = { "Select Item", "Color", "Shape", "Fruit" };
mainComboBox = new JComboBox<String>( items );
mainComboBox.addActionListener( this );
// prevent action events from being fired when the up/down arrow keys are used
mainComboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);
add( mainComboBox );
// Create sub combo box with multiple models
subComboBox = new JComboBox<String>();
subComboBox.setPrototypeDisplayValue("XXXXXXXXXX"); // JDK1.4
add( subComboBox );
JButton arrow = SwingUtils.getDescendantOfType(JButton.class, subComboBox, "Text", "");
Dimension d = arrow.getPreferredSize();
System.out.println(arrow.getClass());
System.out.println(d);
d.width = 100;
arrow.setPreferredSize(d);
String[] subItems1 = { "Select Color", "Red", "Blue", "Green" };
subItems.put(items[1], subItems1);
String[] subItems2 = { "Select Shape", "Circle", "Square", "Triangle" };
subItems.put(items[2], subItems2);
String[] subItems3 = { "Select Fruit", "Apple", "Orange", "Banana" };
subItems.put(items[3], subItems3);
}
public void actionPerformed(ActionEvent e)
{
String item = (String)mainComboBox.getSelectedItem();
Object o = subItems.get( item );
if (o == null)
{
subComboBox.setModel( new DefaultComboBoxModel() );
}
else
{
subComboBox.setModel( new DefaultComboBoxModel( (String[])o ) );
}
}
private static void createAndShowUI()
{
try
{
// UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}
catch (Exception e) { }
JFrame frame = new JFrame("SSCCE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( new ComboBoxTwo() );
frame.setLocationByPlatform( true );
frame.pack();
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
