sco.java~8~

用java编写的画长方形的程序

package sco;

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;
import com.borland.jbcl.layout.*;

public class sco extends Applet {
  int v;
  boolean isStandalone = false;
  JScrollBar s1 = new JScrollBar();
  XYLayout xYLayout1 = new XYLayout();
  /**Get a parameter value*/
  public String getParameter(String key, String def) {
    return isStandalone ? System.getProperty(key, def) :
      (getParameter(key) != null ? getParameter(key) : def);
  }

  /**Construct the applet*/
  public sco() {
  }
  /**Initialize the applet*/
  public void init() {
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  /**Component initialization*/
  private void jbInit() throws Exception {
    s1.setOrientation(JScrollBar.HORIZONTAL);
    s1.setValue(50);
    s1.setRequestFocusEnabled(true);
    s1.addAdjustmentListener(new java.awt.event.AdjustmentListener() {
      public void adjustmentValueChanged(AdjustmentEvent e) {
        s1_adjustmentValueChanged(e);
      }
    });
    this.setLayout(xYLayout1);
    this.add(s1, new XYConstraints(60, 7, 200, -1));
  }
  /**Get Applet information*/
  public String getAppletInfo() {
    return "Applet Information";
  }
  /**Get parameter info*/
  public String[][] getParameterInfo() {
    return null;
  }

  void s1_adjustmentValueChanged(AdjustmentEvent e) {
    v=e.getValue();
    s1.setValue(v);
    l1.setText(String.valueOf(v));
    repaint();
  }

 public void paint(Graphics g){
   g.drawRect(150-v,150-v,2*v,2*v);
 }
 public void update(Graphics g){
    g.clearRect(0,50,300,200);
    paint(g);
 }
 }