update.java~2~

很好得jbuilder100例源代码

package checkbox;

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;

public class update extends Applet {
  boolean isStandalone = false;
  JCheckBox jCheckBox1 = new JCheckBox();
  JCheckBox jCheckBox2 = new JCheckBox();
  JCheckBox jCheckBox3 = new JCheckBox();
  /**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 update() {
  }
  /**Initialize the applet*/
  public void init() {
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  /**Component initialization*/
  private void jbInit() throws Exception {
    jCheckBox1.setText("圆形");
    jCheckBox1.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jCheckBox1_actionPerformed(e);
      }
    });
    jCheckBox2.setText("正方形");
    jCheckBox2.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jCheckBox2_actionPerformed(e);
      }
    });
    jCheckBox3.setText("扇形");
    jCheckBox3.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jCheckBox3_actionPerformed(e);
      }
    });
    this.add(jCheckBox1, null);
    this.add(jCheckBox2, null);
    this.add(jCheckBox3, null);
  }
  /**Get Applet information*/
  public String getAppletInfo() {
    return "Applet Information";
  }
  /**Get parameter info*/
  public String[][] getParameterInfo() {
    return null;
  }

  void jCheckBox1_actionPerformed(ActionEvent e) {
   repaint();
  }
  public void paint(Graphics g){
    g.clearRect(0,20,300,280);
    if(jCheckBox1.isSelected())
          g.drawOval(60,60,30,30);
    if(jCheckBox2.isSelected())
          g.drawRect(120,60,30,30);
    if(jCheckBox3.isSelected())
          g.drawArc(180,60,30,30,0,130);

  }

  void jCheckBox3_actionPerformed(ActionEvent e) {
    repaint();
  }

  void jCheckBox2_actionPerformed(ActionEvent e) {
     repaint();
  }
  public void update(Graphics g){
     paint();
  }
}