Vector comboBoxItems = new Vector(); DefaultComboBoxModel model; // ComboBox Items have gotten from Data Base initially. model = new DefaultComboBoxModel(ComboBoxItems); JComboBox Box = new JComboBox(model);
我将此组合框添加到面板.如果我直接在数据库中添加一些项目,那么我希望在组合框中显示新添加的项目.
当我调试时,我可以看到comboBoxItem中的值,但这些值不会出现在我的组合框中.
如何将这些新添加的值添加到组合框中而不关闭面板？
解决方法
如何使用ComboBoxModel？这样的东西….
JFrame frame = new JFrame("Combo Box Demo");
frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(200,200);
frame.setLayout(new FlowLayout());
Vector comboBoxItems=new Vector();
comboBoxItems.add("A");
comboBoxItems.add("B");
comboBoxItems.add("C");
comboBoxItems.add("D");
comboBoxItems.add("E");
final DefaultComboBoxModel model = new DefaultComboBoxModel(comboBoxItems);
JComboBox comboBox = new JComboBox(model);
frame.add(comboBox);
JButton button = new JButton("Add new element in combo Box");
frame.add(button);
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
model.addElement("F");
}
});
frame.setVisible(true);