package choiceupdate;import java.awt.*;import java.awt.event.*;import java.applet.*;import com.borland.jbcl.layout.*;public class develop extends Applet {  boolean isStandalone = false;  String str1,str2,str3;  XYLayout xYLayout1 = new XYLayout();  Choice choice1 = new Choice();  TextField text1 = new TextField();  TextField text2 = new TextField();  TextField text3 = new TextField();  Label label1 = new Label();  Label label2 = new Label();  Label label3 = new Label();  Label label4 = new Label();  /**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 develop() {  }  /**Initialize the applet*/  public void init() {    try {      jbInit();    }    catch(Exception e) {      e.printStackTrace();    }  }  /**Component initialization*/  private void jbInit() throws Exception {    this.setLayout(xYLayout1);    choice1.setFont(new java.awt.Font("Dialog", 0, 16));    choice1.addItemListener(new java.awt.event.ItemListener() {      public void itemStateChanged(ItemEvent e) {        choice1_itemStateChanged(e);      }    });    label1.setFont(new java.awt.Font("Dialog", 0, 16));    label1.setText("圖形");    label2.setFont(new java.awt.Font("Dialog", 0, 16));    label2.setText("高度（半徑）");    label3.setFont(new java.awt.Font("Dialog", 0, 16));    label3.setText("長度");    label4.setFont(new java.awt.Font("Dialog", 0, 16));    label4.setText("角度");    text1.setText("10");    text1.addFocusListener(new java.awt.event.FocusAdapter() {      public void focusLost(FocusEvent e) {        text1_focusLost(e);      }    });    text2.setText("10");    text2.addFocusListener(new java.awt.event.FocusAdapter() {      public void focusLost(FocusEvent e) {        text2_focusLost(e);      }    });    text3.setText("10");    text3.addFocusListener(new java.awt.event.FocusAdapter() {      public void focusLost(FocusEvent e) {        text3_focusLost(e);      }    });    this.add(choice1,  new XYConstraints(137, 12, 81, 21));    choice1.addItem("圓形");    choice1.addItem("方形");    choice1.addItem("弧形");    this.add(text1,   new XYConstraints(137, 40, 60, -1));    this.add(text2,   new XYConstraints(137, 70, 60, -1));    this.add(text3,     new XYConstraints(137, 100, 60, -1));    this.add(label1,   new XYConstraints(76, 12, 54, -1));    this.add(label2,        new XYConstraints(28, 40, 102, -1));    this.add(label3,    new XYConstraints(76, 70, 54, -1));    this.add(label4,    new XYConstraints(76, 100, 54, -1));  }  /**Get Applet information*/  public String getAppletInfo() {    return "Applet Information";  }  /**Get parameter info*/  public String[][] getParameterInfo() {    return null;  }  void choice1_itemStateChanged(ItemEvent e) {        repaint();  }  public void paint(Graphics g){      g.setColor(Color.red);      switch(choice1.getSelectedIndex() ){         case 0:               str1=text1.getText() ;               str2=text2.getText() ;             if (str1==null)                str1="1";             if (str2==null)                str2="1";             try{                int h=Integer.parseInt(str1);                int w=Integer.parseInt(str2);                g.drawOval(100,150,w,h);             }             catch(Exception e) {                e.printStackTrace();             }          case 1:              str1=text1.getText() ;              str2=text2.getText() ;             if (str1==null)                str1="1";             if (str2==null)                str2="1";             try{                int h=Integer.parseInt(str1);                int w=Integer.parseInt(str2);                g.drawRect(100,150,w,h);             }             catch(Exception e) {                e.printStackTrace();             }          case 2:               str1=text1.getText() ;               str2=text2.getText() ;               str3=text3.getText() ;             if (str1==null)                str1="1";             if (str2==null)                str2="1";             if (str3==null)                str3="1";             try{                int h=Integer.parseInt(str1);                int w=Integer.parseInt(str2);                int a=Integer.parseInt(str3);                g.drawArc(100,150,w,h,0,a);             }             catch(Exception e) {                e.printStackTrace();             }         }    }  void text1_focusLost(FocusEvent e) {     repaint();  }  void text3_focusLost(FocusEvent e) {     repaint();  }  void text2_focusLost(FocusEvent e) {     repaint();  }}