java AdjustmentListener,Scrollbar的使用

 

package gui.event;
import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
public class UseAdjustmentEvent extends Applet implements AdjustmentListener {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private Scrollbar s;
	private TextArea txtValue;
	private Panel p;

	public void init() {
		s = new Scrollbar(Scrollbar.HORIZONTAL, 0, 1, 10, 36);
		// 添加监听者
		s.addAdjustmentListener(this);
		txtValue = new TextArea(5, 25);
		// 界面布局
		p = new Panel(new BorderLayout());
		p.add(s, BorderLayout.NORTH);
		p.add(txtValue, BorderLayout.SOUTH);
		this.add(p);
	}

	public void start() {
	}

	public void adjustmentValueChanged(AdjustmentEvent e) {
		int value;
		Font oldF;
		if (e.getAdjustable() == s) {
			// 得到滚动条的值
			value = e.getValue();
			// 将值写入文本区域
			txtValue.setText(new Integer(value).toString());
			// 按照滚动条的值设置字体
			oldF = txtValue.getFont();
			txtValue.setFont(new Font(oldF.getName(), oldF.getStyle(), value));
		}
	}
}