che.java~15~

很好得jbuilder100例源代码

package radio;

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

public class che extends Applet {
  boolean isStandalone = false;
  int nd;
  ButtonGroup b1 = new ButtonGroup();
  JRadioButton r1 = new JRadioButton();
  JRadioButton r2 = new JRadioButton();
  JRadioButton r3 = new JRadioButton();
  /**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 che() {
  }
  /**Initialize the applet*/
  public void init() {
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  /**Component initialization*/
  private void jbInit() throws Exception {
    r1.setText("圆形");
    r1.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        r1_actionPerformed(e);
      }
    });
    r2.setText("正方形");
    r2.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        r2_actionPerformed(e);
      }
    });
    r3.setText("扇形");
    r3.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        r3_actionPerformed(e);
      }
    });
    this.add(r1, null);
    this.add(r2, null);
    this.add(r3, null);
    b1.add(r1);
    b1.add(r2);
    b1.add(r3);
  }
  /**Get Applet information*/
  public String getAppletInfo() {
    return "Applet Information";
  }
  /**Get parameter info*/
  public String[][] getParameterInfo() {
    return null;
  }

  void r1_actionPerformed(ActionEvent e) {
     clear();
     draw(1);
  }

  void r2_actionPerformed(ActionEvent e) {
     clear();
     draw(2);
  }

  void r3_actionPerformed(ActionEvent e) {
     clear();
     draw(3);
  }
  public void clear(){
     Graphics g.clearRect(20,20,280,280);
  }
  public void draw(int n){
    nd=n;
    repaint();
  }
  public void paint(Graphics g){
    switch(nd){
        case 1:
          g.drawOval(60,60,30,30);
          break;
        case 2:
          g.drawRect(120,60,30,30);
          break;
        case 3:
          g.drawArc(180,60,30,30,0,130);
          break;
     }
  }
  public void update(Graphics g){
     paint(g);
  }
}