java - 繼承

繼承主要是在程式中加上 extends JFrame

如下:

public class TimerDemo extends JFrame implements ActionListener

所以可以用前面的程式修改

如下:


import javax.swing.Timer;
import java.awt.event.*;
import java.util.*;
import java.awt.*;
import javax.swing.*;


public class TimerDemo extends JFrame implements ActionListener {
  static JTextField tbx1=new JTextField(30 ); // 建立1文字方塊物件
  Timer t = new Timer(1000,this);

 /* TimerDemo() {
    t.start();
    }
*/
  public static void main(String args[]) {
    TimerDemo td = new TimerDemo();
    FlowLayout flow=new FlowLayout();
    td.setSize(500,500);

    JButton btn1=new JButton("現在時間"); // 建立按鈕物件 btn1
    btn1.addActionListener(td);
    JPanel p1 = new JPanel(flow);
    td.add(p1); // 在視窗td 內加入 panel 1
    p1.add(tbx1); // 在 panel 1內加入文字方塊
    p1.add(btn1); // 在 panel 1內加入按鈕
    td.setVisible(true);



     // create a dummy frame to keep the JVM running
    //  (for demonstation purpose)
    //java.awt.Frame dummy = new java.awt.Frame();
    //dummy.setVisible(true);
    }

  public void actionPerformed(ActionEvent e) {

  String time =""+Calendar.getInstance().getTime();
    /*if (e.getSource() == t) {
      System.out.println
        ("Being ticked " + Calendar.getInstance().getTime());
      }*/
    tbx1.setText(time);
       }
}

接下來教了Applet

import ij.*;
import java.applet.*;
import java.awt.*;
import ij.process.*;

/**Simple applet that demonstrates how to use ImageJ's ImageProcessor class.*/
public class IPDemo extends Applet {

String name;
Image img;
ImageProcessor ip = null;

public void init() {
setLayout(new BorderLayout());
Panel p = new Panel();
                           p.setLayout(new GridLayout(5, 3));
p.add(new Button("Reset"));
p.add(new Button("Flip"));
p.add(new Button("Invert"));
p.add(new Button("Lighten"));
p.add(new Button("Darken"));
p.add(new Button("Rotate"));
p.add(new Button("Zoom In"));
p.add(new Button("Zoom Out"));
p.add(new Button("Threshsold"));
p.add(new Button("Smooth"));
p.add(new Button("Sharpen"));
p.add(new Button("Find Edges"));
p.add(new Button("Macro 1"));
p.add(new Button("Macro 2"));        
p.add(new Button("Add Noise"));    
                             
               add("South", p);
name = getParameter("img");
img = getImage(getDocumentBase(), name);
MediaTracker tracker = new MediaTracker(this);
tracker.addImage(img, 0);
try {tracker.waitForID(0);}
catch (InterruptedException e){}
if (name.endsWith("jpg"))
ip = new ColorProcessor(img);
else
ip = new ByteProcessor(img);
                                                           
                         
ip.snapshot();

}


public void update(Graphics g) {
paint(g);
}

public void paint(Graphics g) {
g.drawImage(img, 0, 0, this);
}

public boolean action(Event e, Object arg) {
if (e.target instanceof Button) {
String label = (String)arg;
if (label.equals("Reset"))
ip.reset();
else if (label.equals("Flip"))
ip.flipVertical();
else if (label.equals("Invert"))
ip.invert();
else if (label.equals("Lighten"))
ip.multiply(1.1);
else if (label.equals("Darken"))
ip.multiply(0.9);
else if (label.equals("Rotate"))
ip.rotate(30);
else if (label.equals("Zoom In"))
ip.scale(1.2, 1.2);
else if (label.equals("Zoom Out"))
ip.scale(0.8, 0.8);
else if (label.equals("Threshsold"))
ip.autoThreshold();
else if (label.equals("Smooth"))
ip.smooth();
else if (label.equals("Sharpen"))
ip.sharpen();
else if (label.equals("Find Edges"))
ip.findEdges();
else if (label.equals("Macro 1"))
macro1();
else if (label.equals("Macro 2"))
macro2();
else if (label.equals("Add Noise"))
ip.noise(20);
img = ip.createImage();



repaint();
return true;
}
return false;
}

void updateAndDraw() {
                           
                                img.flush();
img = ip.createImage();
getGraphics().drawImage(img, 0, 0, this);
}

void macro1() {
for (int i=10; i<=360; i+=10) {
ip.reset();
ip.rotate(i);
updateAndDraw();
}
}

void macro2() {
double scale = 1, m = 1.2;
for (int i=0; i<20; i++) {
ip.reset();
scale *= m;
ip.scale(scale, scale);
updateAndDraw();
}
for (int i=0; i <20; i++) {
ip.reset();
scale /= m;
ip.scale(scale, scale);
updateAndDraw();
}
}


}

作業
把它按鈕丟掉
但會顯示其效果


import ij.*;
import java.applet.*;
import java.awt.*;
import ij.process.*;

/**Simple applet that demonstrates how to use ImageJ's ImageProcessor class.*/
public class IPDemo extends Applet {

String name;
Image img;
ImageProcessor ip = null;

public void init() {
setLayout(new BorderLayout());
Panel p = new Panel();
                         /*    p.setLayout(new GridLayout(5, 3));
p.add(new Button("Reset"));
p.add(new Button("Flip"));
p.add(new Button("Invert"));
p.add(new Button("Lighten"));
p.add(new Button("Darken"));
p.add(new Button("Rotate"));
p.add(new Button("Zoom In"));
p.add(new Button("Zoom Out"));
p.add(new Button("Threshsold"));
p.add(new Button("Smooth"));
p.add(new Button("Sharpen"));
p.add(new Button("Find Edges"));
p.add(new Button("Macro 1"));
p.add(new Button("Macro 2"));        
p.add(new Button("Add Noise"));      */
                             
               add("South", p);
name = getParameter("img");
img = getImage(getDocumentBase(), name);
MediaTracker tracker = new MediaTracker(this);
tracker.addImage(img, 0);
try {tracker.waitForID(0);}
catch (InterruptedException e){}
if (name.endsWith("jpg"))
ip = new ColorProcessor(img);
else
ip = new ByteProcessor(img);
                                img = ip.createImage();
                                ip.noise(100);
                                ip.findEdges();
                             
                         
ip.snapshot();

}


public void update(Graphics g) {
paint(g);
}

public void paint(Graphics g) {
g.drawImage(img, 0, 0, this);
}

public boolean action(Event e, Object arg) {
if (e.target instanceof Button) {
String label = (String)arg;
if (label.equals("Reset"))
ip.reset();
else if (label.equals("Flip"))
ip.flipVertical();
else if (label.equals("Invert"))
ip.invert();
else if (label.equals("Lighten"))
ip.multiply(1.1);
else if (label.equals("Darken"))
ip.multiply(0.9);
else if (label.equals("Rotate"))
ip.rotate(30);
else if (label.equals("Zoom In"))
ip.scale(1.2, 1.2);
else if (label.equals("Zoom Out"))
ip.scale(0.8, 0.8);
else if (label.equals("Threshsold"))
ip.autoThreshold();
else if (label.equals("Smooth"))
ip.smooth();
else if (label.equals("Sharpen"))
ip.sharpen();
else if (label.equals("Find Edges"))
ip.findEdges();
else if (label.equals("Macro 1"))
macro1();
else if (label.equals("Macro 2"))
macro2();
else if (label.equals("Add Noise"))
ip.noise(20);
img = ip.createImage();



repaint();
return true;
}
return false;
}

void updateAndDraw() {
                           
                                img.flush();
img = ip.createImage();
getGraphics().drawImage(img, 0, 0, this);
}

void macro1() {
for (int i=10; i<=360; i+=10) {
ip.reset();
ip.rotate(i);
updateAndDraw();
}
}

void macro2() {
double scale = 1, m = 1.2;
for (int i=0; i<20; i++) {
ip.reset();
scale *= m;
ip.scale(scale, scale);
updateAndDraw();
}
for (int i=0; i <20; i++) {
ip.reset();
scale /= m;
ip.scale(scale, scale);
updateAndDraw();
}
}


}