首页 > 代码库 > ScrollBar 调整事件监听器AdjustmentListener

ScrollBar 调整事件监听器AdjustmentListener

ScrollBar 组件在滑动滚动块时就会触发调整事件,为了监听调整事件,必须给 ScrollBar 组件对象添加一个调 整事件监听器
AdjustmentListener。该监听器只有一个方法,其一般格式如下

public void adjustmentValueChanged(AdjustmentEvent e){      //调整滚动条发生}


假设现有滚动条组件对象 scrollbar,调整事件使用如下。

scrollbar.addAdjustmentListener(new AdjustmentListener(){        public void adjustmentValueChanged(AdjustmentEvent e)        {               //调整滚动条 do someting        }});


实例如下:

package sup.orange.learn;import java.awt.*;import java.awt.event.AdjustmentEvent;import java.awt.event.AdjustmentListener;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;/** * Created by re-x on 10/27/14. */public class AdjustmentEventDemo extends Frame {    Scrollbar slider;    TextField value;    Label label;    public AdjustmentEventDemo() {        super();        init();    }    public void init() {        setLayout(new GridLayout(1, 3));        slider = new Scrollbar(Scrollbar.HORIZONTAL, 0, 1, 0, 100);        slider.addAdjustmentListener(new AdjustmentListener() {            @Override            public void adjustmentValueChanged(AdjustmentEvent e) {                value.setText(Integer.toString(((Scrollbar)e.getSource()).getValue()));            }        });        value = new TextField("0", 5);        value.setEditable(false);        label = new Label("0~100");        label.setBackground(Color.cyan);        add(label);        add(slider);        add(value);        addWindowListener(new WindowAdapter() {            @Override            public void windowClosing(WindowEvent e) {                super.windowClosing(e);                setVisible(false);                dispose();                System.exit(0);            }        });        setSize(300, 50);        setVisible(true);    }    public static void main(String[] args) {        new AdjustmentEventDemo();    }}

 

ScrollBar 调整事件监听器AdjustmentListener