滚动条是GUI组件,它允许我们查看具有垂直和水平滚动列的不可见行数和不可见的列。
示例
import java.awt.*; import java.awt.event.*; import java.applet.*; /*<applet code="Scroll" width=300 height=300> </applet>*/ public class Scroll extends Applet implements AdjustmentListener { Scrollbar hsb, vsb; int hr, vr; public void init () { hsb=new Scrollbar (Scrollbar.HORIZONTAL, 10, 100, 10, 1000); vsb=new Scrollbar (Scrollbar.VERTICAL, 10, 100, 10, 1000); add (hsb); add (vsb); hsb.addAdjustmentListener (this); vsb.addAdjustmentListener (this); setVisible (true); } public void adjustmentValueChanged (AdjustmentEvent ae) { hr=hsb.getValue (); vr=vsb.getValue (); repaint (); } public void paint (Graphics g) { g.setColor (Color.cyan); g.fillOval (20, 20, hr, vr); } };
日期:2020-04-11 23:04:25 来源:oir作者:oir