Java Basic(64)-JcheckBox

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

public class Gui extends JFrame{

private JTextField tf;

private JCheckBox boldbox;

private JCheckBox italicbox;

public Gui(){

super("the title");

setLayout(new FlowLayout());

tf = new JTextField("This is a sentence", 20);

tf.setFont(new Font("Serif", Font.PLAIN, 14));

add(tf);

boldbox = new JCheckBox("bold");

italicbox = new JCheckBox("italic");

add(boldbox);

add(italicbox);

HandlerClass handler = new HandlerClass();

boldbox.addItemListener(handler);

italicbox.addItemListener(handler);

}

private class HandlerClass implements ItemListener{

}

}

Java Basic(63)-JButton Final Program

import javax.swing.JFrame;

class apples{

public static void main(String[] args){

Gui go = new Gui();

go.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

go.setSize(300, 200);

go.setVisible(true);

}

}

加入這些在 Gui.java:

HandlerClass handler = new HandlerClass();

reg.addActionListener(handler);

custom.addActionListener(handler);

}

private class HandlerClass implements ActionListener{

public void actionPerformed(ActionEvent event){

JOptionPane.showMessageDialog(null, String.format("%s", event.getActionCommand()));

}

這是運行時的結果:

Java Basic(62)-Jbutton

1.創建新class的名稱Gui



2.put 2圖片（40X40）在你的/ bin

import java.awt.FlowLayout;

import java.awt.event.ActionListener;

import java.awt.event.ActionEvent;

import javax.swing.JFrame;

import javax.swing.JButton;

import javax.swing.Icon;

import javax.swing.ImageIcon;

import javax.swing.JOptionPane;

public class Gui extends JFrame{

private JButton reg;

private JButton custom;

public Gui(){

super("The title");

setLayout(new FlowLayout());

reg = new JButton("reg Button");

add(reg);

Icon b = new ImageIcon(getClass().getResource("b.png")); → 圖片名稱

Icon x = new ImageIcon(getClass().getResource("g.png"));

custom = new JButton("Custom",b);

custom.setRolloverSelectedIcon(x);

add(custom);

}

}

Java Basic(61)-Simple Polymorphic Program

public class Fish extends Animal{

public void noise(){

System.out.println("Click Slurk");

}

}

public class Animal {

public void noise(){

System.out.println("Animal dont make noise");

}

}

public class Dog extends Animal{

public void noise(){

System.out.println("Ruff");

}

}

class apples{

public static void main(String[] args){

Animal[] theList = new Animal[2];

Dog d = new Dog();

Fish f = new Fish();

theList[0]=d;

theList[1]=f;

for(Animal x: theList){

x.noise();

}

}

}

這是運行時的結果:

Ruff 

Click Slurk 

Java Basic(60)-Array Holding Many Objects

創建新class稱為AnimalList

public class AnimalList {

private Animal[] theList = new Animal[5];

private int i=0;

public void add(Animal a){

if(i<theList.length){

theList[i]=a;

System.out.println("Animal added at index "+1);

i++;

}

}

}

class apples{

public static void main(String[] args){

AnimalList ALO = new AnimalList();

Dog d = new Dog();

Fish f = new Fish();

ALO.add(d);

ALO.add(f);

}

}

這是運行時的結果:

Animal added at index 0 →這是Dog

Animal added at index 1 →這是Fish

Java Basic(59)-Class to Hold Objects

1.創建新class稱為Dog，Animal和Fish



2.創建新class稱為DogList 在src文件夾中

public class Fish extends Animal{

}

public class Animal {

}

public class Dog extends Animal{

}

public class DogList {

private Dog[] theList = new Dog[5];

private int i=0;

public void add(Dog d){

if(i<theList.length){

theList[i]=d;

System.out.println("Dog added at index "+i);

i++;

}

}

}

class apples{

public static void main(String[] args){

DogList DLO = new DogList();

Dog d = new Dog();

DLO.add(d);

}

}

這是運行時的結果:

Dog added at index 0