import java.awt.*;
public class CheckCombo implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
JComboBox cb = (JComboBox)e.getSource();
CheckComboStore store = (CheckComboStore)cb.getSelectedItem();
CheckComboRenderer ccr = (CheckComboRenderer)cb.getRenderer();
ccr.checkBox.setSelected((store.state = !store.state));
}
private JPanel getContent()
{
String[] ids = { "north", "west", "south", "east" };
Boolean[] values =
{
Boolean.TRUE, Boolean.FALSE, Boolean.FALSE, Boolean.FALSE
};
CheckComboStore[] stores = new CheckComboStore[ids.length];
for(int j = 0; j < ids.length; j++)
stores[j] = new CheckComboStore(ids[j], values[j]);
JComboBox combo = new JComboBox(stores);
combo.setRenderer(new CheckComboRenderer());
combo.addActionListener(this);
JPanel panel = new JPanel();
panel.add(combo);
return panel;
}
public static void main(String[] args)
{
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(new CheckCombo().getContent());
f.setSize(300,160);
f.setLocation(200,200);
f.setVisible(true);
}
}
/** adapted from comment section of ListCellRenderer api */
class CheckComboRenderer implements ListCellRenderer
{
JCheckBox checkBox;
public CheckComboRenderer()
{
checkBox = new JCheckBox();
}
@Override
public Component getListCellRendererComponent(JList list,
Object value,
int index,
boolean isSelected,
boolean cellHasFocus)
{
CheckComboStore store = (CheckComboStore)value;
checkBox.setText(store.id);
checkBox.setSelected(((Boolean)store.state).booleanValue());
checkBox.setBackground(isSelected ? Color.red : Color.white);
checkBox.setForeground(isSelected ? Color.white : Color.black);
return checkBox;
}
}
class CheckComboStore
{
String id;
Boolean state;
public CheckComboStore(String id, Boolean state)
{
this.id = id;
this.state = state;
}
}
其实关键就是combo.setRenderer(new CheckComboRenderer());
自己定义renderer就好了。
下图是运行的结果:
refs:
http://www.coderanch.com/t/343024/GUI/java/Components-JComboBox