import java.applet.Applet;
002: import java.awt.*;
003: import java.util.Random;
004: 
005: public class BackColor extends Applet {
006:  Random gen;  // Random number generator for color selction
007:  String buttonLabel = "Click Me!";
008: 
009:  // Initialize applet
010:  public void init() {
011:   gen = new Random();
012:   Button colorButton = new Button(buttonLabel);
013:   add(colorButton);  // Added to Applet container
014:  }
015: 
016:  // Respond to button click
017:  public boolean action(Event evt, Object what) {
018:   Color c;
019:   if (buttonLabel.equals(what)) {  // Is it our button?
020:    do {
021:     c = new Color(gen.nextInt());
022:    } while (c == getBackground());
023:    setBackground(c);
024:    repaint();
025:   }
026:   return true;  // Kill event
027:  }
028: }
029: 	

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AWT 小應用程序( Applet )和應用程序 List.4 MouseXY/MouseXY.java 
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001: import java.applet.*;
002: import java.awt.*;
003: 
004: public class MouseXY extends Applet {
005:  String location;  // String for X=0 Y=0 display
006: 
007:  // Initialize applet variables and window
008:  public void init() {
009:   setBackground(Color.yellow);
010:   resize(200, 100);
011:   location = new String("Move mouse inside window");
012:  }
013: 
014:  // Paint the location string inside window
015:  public void paint(Graphics g) {
016:   g.drawString(location, 10, 10);
017:  }
018: 
019:  // Create the location string from x and y
020:  public void makeString(int x, int y) {
021:   location = new String(
022:    " X=" + String.valueOf(x) +
023:    " Y=" + String.valueOf(y) );
024:  }
025: 
026:  // Handle all events for this applet
027:  public boolean handleEvent(Event  evt) {
028:   boolean eventHandled = false;
029:   switch (evt.id) {
030:    case Event.MOUSE_DOWN:
031:    case Event.MOUSE_UP:
032:    case Event.MOUSE_DRAG:
033:    case Event.MOUSE_ENTER:
034:    case Event.MOUSE_MOVE: {
035:     makeString(evt.x, evt.y);
036:     repaint();
037:     eventHandled = true;
038:     break;
039:    }
040:    case Event.MOUSE_EXIT: {
041:     location = new String("Move mouse inside window");
042:     repaint();
043:     eventHandled = true;
044:    }
045:   }
046:   if (eventHandled)
047:    return true;
048:   else
049:    return super.handleEvent(evt);
050:  }
051: }

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AWT 小應用程序( Applet )和應用程序 List.5 Delegate/Delegate.java 
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001: import java.awt.*;
002: import java.awt.event.*;
003: import java.applet.Applet;
004: 
005: public class Delegate extends Applet {
006: 
007: // Define two AWT button objects
008:  private Button button1 = new Button("Click This!");
009:  private Button button2 = new Button("Click Me!");
010: 
011:  // Declare an inner class for the listener object
012:  // Toggles between the two buttons
013:  class ButtonListener implements ActionListener {
014:   public void actionPerformed(ActionEvent e) {
015:    if (e.getActionCommand().equals("button1action")) {
016:     button1.setEnabled(false);
017:     button2.setEnabled(true);
018:    } else {
019:     button1.setEnabled(true);
020:     button2.setEnabled(false);
021:    }
022:   }
023:  }
024: 
025: // Applet class constructor
026:  public Delegate() {
027:   ButtonListener actionObject = new ButtonListener();
028:   button1.setActionCommand("button1action");
029:   button1.addActionListener(actionObject);
030:   button2.setActionCommand("button2action");
031:   button2.addActionListener(actionObject);
032:   button1.setEnabled(true);
033:   button2.setEnabled(false);
034:   add(button1);
035:   add(button2);
036:  }
037: }

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AWT 小應用程序( Applet )和應用程序 List.6 RandomColor/RandomColor.java 
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001: import java.applet.Applet;
002: import java.awt.*;
003: import java.awt.event.*;
004: import java.util.Random;
005: 
006: public class RandomColor extends Applet {
007:  
008:  // Constructor 
009:  public RandomColor() {
010:   // Create GUI button object and random generator
011:   Button clickMe = new Button("Click Me!");
012:   final Random gen = new Random();
013: 
014:   // Create listener using an anonymous class
015:   clickMe.addActionListener(new ActionListener() {
016:    public void actionPerformed(ActionEvent e) {
017:     Color c;
018:     do {
019:      c = new Color(gen.nextInt());
020:     } while (c == getBackground());
021:     setBackground(c);
022:     repaint();
023:    }
024:   });
025: 
026:   // Add button to Applet container
027:   add(clickMe);
028:  }
029: }

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AWT 小應用程序( Applet )和應用程序 List.7 ColorApp/ColorApp.java 
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001: import java.applet.Applet;
002: import java.awt.*;
003: import java.awt.event.*;
004: import java.util.Random;
005: 
006: public class ColorApp
007:  extends Panel 
008:  implements ActionListener {
009: 
010:  protected Random gen = new Random();
011:  
012:  // Constructor 
013:  public ColorApp() {
014:   Button clickMe = new Button("Click Me!");
015:   clickMe.addActionListener(this);
016:   add(clickMe);  // Add button to panel
017:  }
018: 
019:  // The button's event handler
020:  public void actionPerformed(ActionEvent e) {
021:   Color c;
022:   do {
023:    c = new Color(gen.nextInt());
024:   } while (c == getBackground());
025:   setBackground(c);
026:   repaint();
027:  }
028: 
029:  // The main program
030:  public static void main(String[] args) {
031: 
032:   // Create frame and set its size
033:   Frame frame = new Frame("Color Application Demo");
034:   frame.setSize(250, 200);
035:   frame.setLocation(50, 50);
036: 
037:   // End the program when the window is closed
038:   frame.addWindowListener(new WindowAdapter() {
039:    public void windowClosing(WindowEvent e) {
040:     System.exit(0);
041:    }
042:   });
043: 
044:   // Add the ColorApp panel to the frame and show it
045:   frame.add(new ColorApp(), BorderLayout.CENTER);
046:   frame.show();
047:  }
048: }

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