我对JComboBox有疑问。我正在尝试使用向上向下箭头键进行循环遍历。但是当我按下向下箭头键后到达底部时,我将所选索引设置为0.但是它到达项目索引1.相反,另一种方式。当按下顶部并按下向上键时,选择最终元素之前的项目。有办法解决这个问题吗?
提前致谢。
public class ComboTest {
public static void main(String[] args){
JFrame f = new JFrame("Java Swing Examples");
final JComboBox c = new JComboBox();
for ( int i = 0; i < 5 ; i++) {
c.addItem(i+"");
}
f.getContentPane().add(c);
f.pack();
f.setMinimumSize(new Dimension(300,200));
f.setPreferredSize(new Dimension(300,200));
c.addKeyListener(new KeyListener()
{
public void keyTyped(KeyEvent e) { }
public void keyReleased(KeyEvent e) {
int index = c.getSelectedIndex();
System.out.println("Released: "+index);
}
public void keyPressed(KeyEvent e) {
int index = c.getSelectedIndex();
System.out.println("Pressed: "+index);
if(index == c.getItemCount()-1 && e.getKeyCode()==KeyEvent.DOWN) {
c.setSelectedIndex(0);
} else if (index == 0 && e.getKeyCode() == KeyEvent.VK_UP) {
c.setSelectedIndex(c.getItemCount()-1);
}
}
});
答案 0 :(得分:0)
我们需要在设置索引后使用该事件。
e.consume()
解决!!!