我有个问题。我有一个 JPanel 的元素。在这个 JPanel 中将有四个 JButton 和图像。此图像是“绿色 LED 灯”，会根据按下的 JButton 而变化。它工作得很好。但我也希望 JComboBox 更改此参数。
这就是问题所在。虽然参数（从 1 到 4）在变化，（这显示 JLabel 靠近 LED），但图片（LED 灯）不想将其更改为右侧。
该计划分为3类。
MyFrame.class 这个主类。
public class MyFrame extends JFrame {
int ctrlTriggers = 1;
private JLabel label = new JLabel();
private Triggers triggers;
private String[] typeTrig = {"1", "2", "3", "4"};
public MyFrame() {
JFrame frame = new JFrame("JComboBox Problem");
frame.setBounds(50, 0, 800, 240);
frame.setLayout(new BorderLayout());
int tvalue = 1;
String tstr = Integer.toString(tvalue);
JPanel panelTrig = new JPanel(new BorderLayout());
label = new JLabel(tstr, 4);
panelTrig.add(label);
final JLabel et = label;
triggers = new Triggers(typeTrig, "trigger " + Integer.toString(1));
triggers.addChangeListener(new ChangeListener() {
public void stateChanged(ChangeEvent e) {
Triggers tr = (Triggers) e.getSource();
int vol;
vol = (int) tr.getValue();
et.setText(Integer.toString(vol));
}
});
panelTrig.add(triggers, BorderLayout.LINE_START);
// JCOMBOBOX
JPanel pCombo = new JPanel();
pCombo.setLayout(new FlowLayout());
Presets combo = new Presets();
combo.addChangeListener(new ChangeListener() {
public void stateChanged(ChangeEvent e) {
Presets presetcombo = (Presets) e.getSource();
int tval;
tval = (int) presetcombo.getValue(ctrlTriggers);
label.setText(Integer.toString(tval));
triggers.setValue(tval);
}
});
pCombo.add(combo, BorderLayout.CENTER);
frame.add(pCombo, BorderLayout.CENTER);
frame.add(panelTrig, BorderLayout.LINE_START);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
frame.show();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new MyFrame();
}
});
}
}
Triggers.class这个类是 JPanel，其中有 4 个 JButton 和 'LED like image'
public class Triggers extends JPanel
implements ActionListener, ItemListener {
public Triggers(String s[], String name) {
JPanel panel = new JPanel(new BorderLayout());
this.value = Integer.parseInt(s[selected]);
for (int i = 0; i < s.length; i++) {
ImageIcon cup = new ImageIcon();
button[i] = new JButton(z[i], cup);
button[i].setPreferredSize(new Dimension(70, 25));
Font font = button[i].getFont();
button[i].setFont(new Font(font.getFontName(), font.getStyle(), 10));
button[i].setActionCommand(s[i]);
if (i == selected) {
button[i].setSelected(true);
} else {
button[i].setSelected(false);
}
}
ButtonGroup group = new ButtonGroup();
for (int i = 0; i < s.length; i++) {
group.add(button[i]);
button[i].addActionListener(this);
button[i].addItemListener(this);
}
diody = new JLabel(createImageIcon("/resources/diody/"
+ this.value
+ ".png"));
diody.setPreferredSize(new Dimension(20, 100));
JPanel triggs = new JPanel(new FlowLayout());
triggs.setPreferredSize(new Dimension(80, 120));
for (int i = 0; i < s.length; i++) {
triggs.add(button[i]);
}
panel.add(triggs, BorderLayout.LINE_START);
panel.add(diody, BorderLayout.LINE_END);
add(panel);
}
public void actionPerformed(ActionEvent e) {
cmd = e.getActionCommand();
diody.setIcon(createImageIcon("/resources/diody/"
+ cmd
+ ".png"));
if (cmd.equals("1")) {
setValue(1);
} else if (cmd.equals("2")) {
setValue(2);
} else if (cmd.equals("3")) {
setValue(3);
} else if (cmd.equals("4")) {
setValue(4);
}
}
public static ImageIcon createImageIcon(String path) {
java.net.URL imgURL = Triggers.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL);
} else {
System.err.println("Couldn't find file: " + path);
return null;
}
}
public int setController() {
return value;
}
public void setValue(int k) {
this.value = k;
cmd = Integer.toString(this.value);
repaint();
fireChangeEvent();
}
public int getValue() {
return this.value;
}
public void setSel(int k) {
selected = k;
repaint();
fireChangeEvent();
}
public void itemStateChanged(ItemEvent ie) {
String s = (String) ie.getItem();
}
public void addChangeListener(ChangeListener cl) {
listenerList.add(ChangeListener.class, cl);
}
public void removeChangeListener(ChangeListener cl) {
listenerList.remove(ChangeListener.class, cl);
}
protected void fireChangeEvent() {
Object[] listeners = listenerList.getListenerList();
for (int i = listeners.length - 2; i >= 0; i -= 2) {
if (listeners[i] == ChangeListener.class) {
if (changeEvent == null) {
changeEvent = new ChangeEvent(this);
}
((ChangeListener) listeners[i + 1]).stateChanged(changeEvent);
}
}
}
private ChangeEvent changeEvent = null;
private EventListenerList listenerList = new EventListenerList();
private JLabel diody;
private int x = 1;
private int y = 4;
private JButton button[] = new JButton[y];
double border = 4;
double vborder = 1;
int controller[] = new int[4];
String z[] = {"1", "2", "3", "4"};
private int selected;
private int value;
private String cmd;
}
类 Presets这里是 JCombobox。
public class Presets extends JPanel
implements ActionListener {
private int value;
private int[] ctrlIdx = new int[27];
private int controller;
private ChangeEvent changeEvent = null;
private EventListenerList listenerList = new EventListenerList();
private JLabel label;
private String[][] presets = {
{"0", "3"},
{"1", "2"},
{"2", "3"},
{"3", "1"},
{"4", "4"},
{"5", "2"},};
String[] ctrlName = {"preset 1 (value 3)", "preset 2 (value 2)", "preset 3 (value 3)", "preset 4 (value 1)", "preset 5 (value 4)", "preset 5 (value 2)"};
public Presets() {
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.setPreferredSize(new Dimension(600, 30));
JComboBox combolist = new JComboBox(ctrlName);
combolist.setSelectedIndex(2);
combolist.addActionListener(this);
combolist.setPreferredSize(new Dimension(300, 30));
label = new JLabel();
label.setFont(label.getFont().deriveFont(Font.ITALIC));
label.setHorizontalAlignment(JLabel.CENTER);
int indeks = combolist.getSelectedIndex();
updateLabel(ctrlName[combolist.getSelectedIndex()], indeks);
label.setBorder(BorderFactory.createEmptyBorder(10, 0, 0, 0));
label.setPreferredSize(new Dimension(300, 30));
panel.add(combolist, "East");
add(panel);
setPreferredSize(new Dimension(600, 40));
}
public void setSelectedItem(int a) {
}
public void setValue(int c, int v) {
controller = c;
value = v;
ctrlIdx[controller] = value;
repaint();
fireChangeEvent();
}
public int getController() {
return controller;
}
public int getValue(int c) {
int w = (int) ctrlIdx[c];
return (int) w;
}
public void actionPerformed(ActionEvent e) {
JComboBox cb = (JComboBox) e.getSource();
String pres = (String) cb.getSelectedItem();
int indeks = cb.getSelectedIndex();
updateLabel(pres, indeks);
for (int i = 0; i < ctrlName.length; i++) {
for (int j = 0; j < 2; j++) {
setValue(j, Integer.parseInt(presets[indeks][j]));
}
}
}
protected void updateLabel(String name, int ii) {
label.setToolTipText("A drawing of a " + name.toLowerCase());
}
protected static ImageIcon createImageIcon(String path) {
java.net.URL imgURL = Presets.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL);
} else {
System.err.println("Couldn't find file: " + path);
return null;
}
}
public void addChangeListener(ChangeListener cl) {
listenerList.add(ChangeListener.class, cl);
}
public void removeChangeListener(ChangeListener cl) {
listenerList.remove(ChangeListener.class, cl);
}
protected void fireChangeEvent() {
Object[] listeners = listenerList.getListenerList();
for (int i = listeners.length - 2; i >= 0; i -= 2) {
if (listeners[i] == ChangeListener.class) {
if (changeEvent == null) {
changeEvent = new ChangeEvent(this);
}
((ChangeListener) listeners[i + 1]).stateChanged(changeEvent);
}
}
}
}
有人可以帮助我，我做错了什么？