AdjustmentListener接口用于接收调整事件。处理调整事件的类需要实现此接口。
类声明
以下是java.awt.event.AdjustmentListener接口的声明 -
public interface AdjustmentListener
extends EventListener
接口方法
| 编号 | 方法 | 描述说明 |
|---|---|---|
| 1 | void adjustmentValueChanged(AdjustmentEvent e) |
调整值的值发生变化时调用。 |
方法继承
该类从以下接口继承方法 -
java.awt.event.EventListener
AdjustmentListener示例
使用编辑器创建以下Java程序：AdjustmentListenerDemo.java
package com.yiibai.swing.listener;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class AdjustmentListenerDemo {
private JFrame mainFrame;
private JLabel headerLabel;
private JLabel statusLabel;
private JPanel controlPanel;
public AdjustmentListenerDemo() {
prepareGUI();
}
public static void main(String[] args) {
AdjustmentListenerDemo swingListenerDemo = new AdjustmentListenerDemo();
swingListenerDemo.showAdjustmentListenerDemo();
}
private void prepareGUI() {
mainFrame = new JFrame("Java SWING AdjustmentListener示例");
mainFrame.setSize(400, 400);
mainFrame.setLayout(new GridLayout(3, 1));
headerLabel = new JLabel("", JLabel.CENTER);
statusLabel = new JLabel("", JLabel.CENTER);
statusLabel.setSize(350, 100);
mainFrame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowEvent) {
System.exit(0);
}
});
controlPanel = new JPanel();
controlPanel.setLayout(new FlowLayout());
mainFrame.add(headerLabel);
mainFrame.add(controlPanel);
mainFrame.add(statusLabel);
mainFrame.setVisible(true);
}
private void showAdjustmentListenerDemo() {
headerLabel.setText("Listener in action: AdjustmentListener");
JPanel panel = new JPanel();
JScrollBar scrollbar = new JScrollBar();
scrollbar.addAdjustmentListener(new CustomAdjustmentListener());
panel.add(scrollbar);
controlPanel.add(panel);
mainFrame.setVisible(true);
}
class CustomAdjustmentListener implements AdjustmentListener {
public void adjustmentValueChanged(AdjustmentEvent e) {
statusLabel.setText("Adjustment value: " + Integer.toString(e.getValue()));
}
}
}
执行上面示例代码，得到以下结果：
