java GUI编程

一、GUI编程简介

GUI：图形用户界面，Graphical User Interface，简称 GUI，又称图形用户接口
组件
- 窗口
- 弹窗
- 面板
- 文本框
- 列表框
- 按钮
- 图片
- 监听事件
  - 鼠标事件
  - 键盘事件
- 外挂：因为Java是基于JVM运行的，所以不会被检测出来
- 破解工具
简介
- GUI的核心技术：Swing AWT
- 不流行的原因：
  - 因为界面不美观
  - 需要jre环境
- 学习原因：
  - MVC架构的基础，后期需要了解MVC架构，了解监听
  - 可以写出自己心中想要的一些小工具
  - 工作时，可能需要维护到swing界面，概率很小，因为这个技术已经很老了

二、AWT

1、AWT介绍

AWT（抽象窗口工具）介绍
- 包含了很多类和接口
- Eclipse：就是java写的
- 元素：窗口、按钮、文本框
- java.awt包中
- awt包总体框架：
- 补充知识：java用的包都在rt.jar中，可解压打开

2、Frame窗口程序实例

package www.xiaoxiao.com;

import java.awt.*;

public class FrameDemo {
    public static void main(String[] args) {
        Frame frame = new Frame("myFist window program");
        //设置可见性
        frame.setVisible(true);
        //设置长宽
        frame.setSize(400,400);
        //设置初使位置
        frame.setLocation(100,100);
        //设置背景颜色
        frame.setBackground(new Color(6, 248, 190));
        //设置固定大小
        frame.setResizable(false);
    }
}

通过封装实现多个窗口：

package www.xiaoxiao.com;
import java.awt.*;
public class FrameDemo02 {
    public static void main(String[] args) {
        new MyFrame(100,100,400,400).setBackground(Color.BLUE);
        new MyFrame(600,100,400,400).setBackground(Color.CYAN);
        new MyFrame(600,600,400,400).setBackground(Color.black);
        new MyFrame(100,600,400,400).setBackground(Color.GRAY);
    }
}
class MyFrame extends Frame{
    static int id=0;//计数器
    public MyFrame(int x,int y,int w,int h)  {
        super("myFrame"+(id++));
        setLocation(x,y);//子类继承了父类的方法
        this.setLocation(x,y);//不管是用this还是super，子类现在并没有重写父类的方法，因此都是调用父类的方法
        //super.setLocation(x,y);
        setResizable(false);
        setSize(w,h);
        setVisible(true);
    }
}

3、面板Panel实例

package www.xiaoxiao.com.AWT;

import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;

//面板
public class PanelDemo {
    public static void main(String[] args) {
        Frame frame=new Frame();
        Panel panel=new Panel();
        frame.setVisible(true);
        frame.setBounds(200,200,400,400);
        frame.setBackground(Color.CYAN);
        panel.setBounds(100,100,200,200);//设置属性是相对于add到的容器来说的
        panel.setVisible(true);
        panel.setBackground(Color.BLUE);
        frame.add(panel);
        frame.setLayout(null);//不设置布局无效果，清空布局，默认布局是继承自Window的BorderLayout，会覆盖
        //设置关闭按钮监听
        //使用适配器模式，只重写窗口closeing事件
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);//返回0为正常退出
            }
        });
    }
}

补充：(为什么Frame要setvisible=true,而其他组件不需要设置)经调试，发现源码中：
- Window(顶级窗口)的visible初始值为false（Frame.visible为false）
- 而Component的visible的初始值为true,即按钮面板等组件的visible属性默认为true

4、Layout布局

流式布局:布局方式像流一样，可以指定以左中右为开始位置部件依次进行顺序排列

package www.xiaoxiao.com.AWT;

import java.awt.*;

public class LayoutDemo01 {
    public static void main(String[] args) {
        //流式布局：可以定义从中间、左、右来进行排列 ，add的组件按顺序依次排列
        Frame frame = new Frame("流式布局");
        Button btn1 = new Button("btn1");
        Button btn2 = new Button("btn2");
        Button btn3 = new Button("btn3");
        frame.add(btn1);
        frame.add(btn2);
        frame.add(btn3);
        frame.setVisible(true);
        frame.setSize(500,500);
        frame.setLayout(new FlowLayout(FlowLayout.LEFT));
        frame.setLayout(new FlowLayout(FlowLayout.RIGHT));
        frame.setLayout(new FlowLayout(FlowLayout.CENTER));
        frame.setLayout(new FlowLayout(FlowLayout.CENTER,50,50));//后面两个参数为组件间的间隙
    }
}

东南西北中布局（BorderLayout，Frame的默认布局）

package www.xiaoxiao.com.AWT;

import java.awt.*;

//东南西北中布局
public class LayoutDemo02 {
    public static void main(String[] args) {
        Frame frame = new Frame();//不写参数，标题就没有
        Button east = new Button("east");
        Button west = new Button("west");
        Button south = new Button("south");
        Button north = new Button("north");
        Button center = new Button("center");
        frame.setVisible(true);
        frame.setSize(500,500);
        //Frame的默认布局就是BorderLayout
        //BorderLayout borderLayout = new BorderLayout(50,50);
        //frame.setLayout(borderLayout);
        frame.add(east,BorderLayout.EAST);
        frame.add(west,BorderLayout.WEST);
        frame.add(south,BorderLayout.SOUTH);
        frame.add(north,BorderLayout.NORTH);
        frame.add(center,BorderLayout.CENTER);
        //如果add方法不指定第二个参数（容器），默认会写到BorderLayout.Center中,要注意一个组件对象只能写到一个地方，对同一个组件对象进行多次位置变化时，以最后一次变化为准
    }
}

*：Frame继承自Window，window的初使化方法中默认设置为borderLayout，如下图。

网格布局GridLayout

package www.xiaoxiao.com.AWT;

import java.awt.*;

public class LayoutDemo03 {
    public static void main(String[] args) {
        Frame frame=new Frame("GridLayout");
        Button bt1=new Button("bt1");
        Button bt2=new Button("bt2");
        Button bt3=new Button("bt3");
        Button bt4=new Button("bt4");
        Button bt5=new Button("bt5");
        frame.setVisible(true);
        frame.setSize(500,500);
        frame.setLayout(new GridLayout(2,3,50,50));
        frame.add(bt1);
        //frame.add(bt2);重复加没用
        frame.add(bt2);
        frame.add(bt3);
        frame.add(bt4);
        frame.add(bt5);
    }
}

5、布局练习：实现下图的嵌套布局

package www.xiaoxiao.com.AWT;

import javafx.scene.layout.Pane;

import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class LayoutTestDemo {
    public static void main(String[] args) {
        Frame frame = new Frame("课堂练习");
        Panel panel1=new Panel();
        Panel panel2=new Panel();
        Panel panel3=new Panel();
        Panel panel4=new Panel();
        panel1.setBackground(Color.CYAN);
        panel2.setBackground(Color.blue);
        frame.setBounds(300,300,300,300);
        frame.add(panel1);
        frame.add(panel2);
        panel1.setLayout(new BorderLayout());
        panel1.add(new Button("no1West"),BorderLayout.WEST);
        panel1.add(new Button("no1Eest"),BorderLayout.EAST);
        panel1.add(panel3);//默认为添加到BorderLayout.Center
        panel3.setLayout(new GridLayout(2,1));
        panel3.add(new Button("no1CenterNorth"));
        panel3.add(new Button("no1CenterSouth"));
        panel2.setLayout(new BorderLayout());
        panel2.add(new Button("no2West"),BorderLayout.WEST);
        panel2.add(new Button("no2Eest"),BorderLayout.EAST);
        panel2.add(panel4);
        panel4.setLayout(new GridLayout(2,2));
        panel4.add(new Button("btn1"));
        panel4.add(new Button("btn2"));
        panel4.add(new Button("btn3"));
        panel4.add(new Button("btn4"));
        frame.setLayout(new GridLayout(2,1));
        frame.setVisible(true);
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}

6、AWT（抽象窗口工具）总结

Frame是一个顶级窗口
Panel无法单独显示，必须添加到某个容器中
布局管理器：
- 流式
- 东西南北中
- 网格式

7、事件监听

事件监听：当某个事情发生时，要执行什么操作

package www.xiaoxiao.com.AWT;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class MonitorDemo01 {
    public static void main(String[] args) {
        //事件监听
        Frame frame=new Frame();
        Button button1=new Button("button");
        button1.addActionListener(new MyListener());
        frame.add(button1);
        frame.pack();//自适应
        WindowClose(frame);
        frame.setVisible(true);
    }
    //抽取方法
    private static void WindowClose(Frame frame){
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}
class MyListener implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("aaa");
    }
}

多个部件共用一个监听事件

package www.xiaoxiao.com.AWT;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Date;

//多个组件共用一个监听
public class MonitorDemo02 {
    public static void main(String[] args) {
        Frame frame = new Frame("start-stop");
        Button button1 = new Button("start");
        Button button2 = new Button("stop");
        button1.setActionCommand("already start");
        frame.setBounds(500,500,500,500);
        frame.setLayout(new FlowLayout());
        frame.add(button1);
        frame.add(button2);
        frame.setVisible(true);
        MyMonitor myMonitor=new MyMonitor();
        //这样做的好处是节省了代码
        button1.addActionListener(myMonitor);
        button2.addActionListener(myMonitor);
    }
}
class  MyMonitor implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getActionCommand().equals("stop")){
            System.out.print(new Date(e.getWhen()).toLocaleString()+": ");
            System.out.println(e.getActionCommand());//如果组件中设置了ActionCommand则返回设置的，否则返回标题
        }else{
            System.out.println("我没停止");
        }
    }
}

8、文本框及其监听

package www.xiaoxiao.com.AWT;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

//输入框及其监听事件
public class TextFieldDemo {
    public static void main(String[] args) {
        //一般项目的main方法中只有一个启动方法
        new MyTestFrame();
    }
}
class MyTestFrame extends Frame{
    public MyTestFrame() throws HeadlessException {
        TextField textField=new TextField();
        add(textField);//相当于this.add()
        MyTestListener testListener=new MyTestListener();
        //TextField的监听事件是当回车按下
        textField.addActionListener(testListener);
        //设置回显字符（多用于密码密码）
        textField.setEchoChar('*');
        setVisible(true);
        pack();//自适应
        setLocation(400,440);
        setSize(500,500);
    }
}
class MyTestListener implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e) {
        TextField field=(TextField) e.getSource();//获取资源
        System.out.println(field.getText());
        field.setText(null);//按下回车后将文本框内容置为null
    }
}

9、简易计算机的实现

原始代码

//入口类
public class SimplyCalc {
    public static void main(String[] args) {
        //程序入口
        new MyCalcFrame();
    }
}
//窗体实现类
import java.awt.*;
public class MyCalcFrame extends Frame {
    public MyCalcFrame(){
        TextField num1 = new TextField(10);//长度
        TextField num2 = new TextField(10);//长度
        TextField num3 = new TextField(20);//长度
        Button equal = new Button("=");
        Label label = new Label("+");
        equal.addActionListener(new MyListener(num1,num2,num3));
        setLayout(new FlowLayout());
        add(num1);
        add(label);
        add(num2);
        add(equal);
        add(num3);
        pack();//要在加之前用，否则会出错
        setLocation(500,500);
        setVisible(true);
    }
}
//监听实现类
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class MyListener implements ActionListener {
    private TextField num1;
    private TextField num2;
    private TextField num3;
    public MyListener(TextField num1, TextField num2, TextField num3) {
        this.num1=num1;
        this.num2=num2;
        this.num3=num3;
    }
    @Override
    public void actionPerformed(ActionEvent e) {
        int n1 = Integer.parseInt(num1.getText());
        int n2 = Integer.parseInt(num2.getText());
        num3.setText(""+(n1+n2));
        num1.setText("");
        num2.setText("");
    }
}

使用组合的方式优化

//入口
public class SimplyCalc {
    public static void main(String[] args) {
        //程序入口
        new MyCalcFrame().load();
    }
}
//窗体实现类，将属性和方法抽离，使其更加对象化
import java.awt.*;
public class MyCalcFrame extends Frame {
    //属性，要写在构造方法前，否则MyListener无法引用
    TextField num1,num2,num3;
    //方法，直接调用方法
    public void load(){
        num1 = new TextField(10);//长度
        num2 = new TextField(10);//长度
        num3 = new TextField(20);//长度
        Button equal = new Button("=");
        Label label = new Label("+");
        equal.addActionListener(new MyListener(this));
        setLayout(new FlowLayout());
        add(num1);
        add(label);
        add(num2);
        add(equal);
        add(num3);
        pack();//要在加之前用，否则会出错
        setLocation(500,500);
        setVisible(true);
    }
}

//监听实现类，使用组合的方式，直接使用MyCalcFrame当做属性，可以简化代码
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class MyListener implements ActionListener {
    //使用组合的方法直接调用对象就可心使用里面的属性了
    private MyCalcFrame myCalcFrame=null;
    public MyListener(MyCalcFrame myCalcFrame) {
       this.myCalcFrame=myCalcFrame;
    }
    @Override
    public void actionPerformed(ActionEvent e) {
        int n1 = Integer.parseInt(myCalcFrame.num1.getText());
        int n2 = Integer.parseInt(myCalcFrame.num2.getText());
        myCalcFrame.num3.setText(""+(n1+n2));
        myCalcFrame.num1.setText("");
        myCalcFrame.num2.setText("");
    }
}

使用内部类的方式(更好的包装)

//内部类最大的好处，就是可以畅通无阻的访问外部的属性和方法
//入口
public class SimplyCalc {
    public static void main(String[] args) {
        //程序入口
        new MyCalcFrame().load();
    }
}

//实现
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class MyCalcFrame extends Frame {
    //属性，要写在构造方法前，否则MyListener无法引用
    TextField num1,num2,num3;
    //方法，直接调用方法
    public void load(){
        num1 = new TextField(10);//长度
        num2 = new TextField(10);//长度
        num3 = new TextField(20);//长度
        Button equal = new Button("=");
        Label label = new Label("+");
        equal.addActionListener(new MyListener());
        setLayout(new FlowLayout());
        add(num1);
        add(label);
        add(num2);
        add(equal);
        add(num3);
        pack();//要在加之前用，否则会出错
        setLocation(500,500);
        setVisible(true);
    }
    private class MyListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            int n1 = Integer.parseInt(num1.getText());
            int n2 = Integer.parseInt(num2.getText());
            num3.setText(""+(n1+n2));
            num1.setText("");
            num2.setText("");
        }
    }
}

10、画笔

package www.xiaoxiao.com.AWT;
import java.awt.*;
public class PaintDemo {
    public static void main(String[] args) {
        new MyPaint().overLoad();
    }
}
class MyPaint extends Frame{
    public void overLoad(){
        setBounds(300,300,600,500);
        setVisible(true);//调用这个方法默认会调用repaint()方法进行重绘
    }
    @Override
    public void paint(Graphics g) {
        g.setColor(Color.CYAN);
        //g.drawRect(100,200,88,99);
        g.fillRect(100,200,88,99);
        g.setColor(Color.BLUE);
        //g.drawOval(200,200,100,100);
        g.fillOval(200,200,100,100);
        //一般来说在画笔使用完成后，要将其初始化为原始颜色，方便下次调用
        //默认为黑色
        g.setColor(Color.BLACK);
    }
}

11、鼠标监听，实现单击一下鼠标画一个点

实现思想

package www.xiaoxiao.com.AWT;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.Iterator;

public class MousePaintPointDemo {
    public static void main(String[] args) {
        new MyMouseFrame("鼠标监听");
    }
}
//首先要有个窗体
class MyMouseFrame extends Frame{
    ArrayList points;
    public MyMouseFrame(String title){
        super(title);
        points=new ArrayList();
        setBounds(300,300,400,500);
        addMouseListener(new MyMouseLissener());
        setVisible(true);
    }
    @Override
    public void paint(Graphics g) {
        super.paint(g);
        Iterator iterator = points.iterator();
        while (iterator.hasNext()){
            Point next = (Point) iterator.next();
            g.setColor(Color.BLUE);
            g.fillOval(next.x,next.y,10,10);
        }
    }
    public void addPoint(Point point){
        points.add(point);
    }
    //单击鼠标监听事件,适配器模式
    class MyMouseLissener extends MouseAdapter{
        @Override
        public void mousePressed(MouseEvent e) {
            //鼠标单击时获取鼠标的位置（就是点的位置），将点加到ArrayList中
            //MyMouseFrame frame = (MyMouseFrame) e.getSource();//获取资源对象，为当前窗体
            int x = e.getX();//获取x坐标
            int y = e.getY();//获取y会标
            addPoint(new Point(x,y));
            repaint();
        }
    }
}

12、窗口监听

package www.xiaoxiao.com.AWT;
import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class WindowLinsenerDemo {
    public static void main(String[] args) {
        new MyFrame1();
    }
}
class MyFrame1 extends Frame{
    public MyFrame1() throws HeadlessException {
        setBounds(500,400,500,500);
        setBackground(Color.BLUE);
        setVisible(true);
        addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.out.println("窗口正在关闭");
            }
            @Override
            public void windowIconified(WindowEvent e) {
                //窗口最小化
                System.out.println("窗口最小化");
            }
            @Override
            public void windowDeiconified(WindowEvent e) {
                //窗口从最小化恢复
                System.out.println("窗口从最小化恢复");
            }
            @Override
            public void windowActivated(WindowEvent e) {
                System.out.println("窗口激活");
            }
            @Override
            public void windowDeactivated(WindowEvent e) {
                System.out.println("窗口未激活");
            }
        });
    }
}

13、键盘监听

package www.xiaoxiao.com.AWT;

import java.awt.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

public class KeyDemo {
    public static void main(String[] args) {
        new MyKeyFrame();
    }
}
class MyKeyFrame extends Frame{
    public MyKeyFrame() throws HeadlessException {
        setBounds(100,100,500,500);
        setVisible(true);
        addKeyListener(new KeyAdapter() {
            //键入字符
            @Override
            public void keyTyped(KeyEvent e) {
                int keyCode = e.getKeyCode();
                System.out.println((char) keyCode+"typed");
            }
            //按下
            @Override
            public void keyPressed(KeyEvent e) {
                int keyCode = e.getKeyCode();
                System.out.println((char)keyCode+"yaxia");
            }
            //弹起
            @Override
            public void keyReleased(KeyEvent e) {
                int keyCode = e.getKeyCode();
                System.out.println((char)keyCode+"released");
            }
        });
    }
}

三、Swing

Swing和AWT差不多，是在AWT的基础上进行的优化，多了一些组件等

1、JFrame窗口

关于设置jFrame的背景
- 在直接调用setBackground(Color.red)这个方法后，的确设置了JFrame的背景颜色，而你看到的却不是直接的JFrame，而是JFrame.getContentPane()。而JFrame上的contentPane默认是Color.WHITE的，所以，无论对JFrame怎么设置背景颜色，看到的都只是contentPane.

package www.xiaoxiao.com.Swing;

import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.colorchooser.ColorSelectionModel;
import java.awt.*;

public class WindowDemo {
    //初始化
    public void init(){
        JFrame jFrame = new JFrame();
        jFrame.setBounds(100,100,500,500);
        //不能直接设置背景
        //jFrame.setBackground(Color.BLUE);无效果
        //方法一：
        //1.获取容器
        Container contentPane = jFrame.getContentPane();
        //2.设置容器的颜色
        contentPane.setBackground(Color.blue);
        //方法二：jFrame.getContentPane().setVisible(false)将其设置为不可见,但这种方式会导致加进来的组件不可见
        //jFrame.getContentPane().setVisible(false);
        //jFrame.setBackground(Color.BLUE);
        contentPane.setLayout(new GridLayout(2,2));
        //面板
        JPanel jPanel = new JPanel();
        jPanel.setSize(20,20);
        //jPanel.setBounds(10,10,200,200);
        jPanel.setBackground(Color.CYAN);
        jFrame.add(jPanel);
        JPanel jPanel2 = new JPanel();
        jPanel2.setSize(20,20);
        //jPanel.setBounds(10,10,200,200);
        jPanel2.setBackground(Color.GRAY);
        jFrame.add(jPanel2);
        JLabel jLabel = new JLabel("hello world!");
        //设置水平居中
        jLabel.setHorizontalAlignment(SwingConstants.CENTER);
        jFrame.add(jLabel);
        //设置退出
        jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jFrame.setVisible(true);
    }
    public static void main(String[] args) {
        new WindowDemo().init();
    }
}

2、JDialog

package www.xiaoxiao.com.Swing;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

//弹窗
public class JDialogDemo {
    public JDialogDemo() {
        JFrame jFrame = new JFrame();
        jFrame.setBounds(100,100,800,400);
        Container contentPane = jFrame.getContentPane();
        contentPane.setBackground(Color.BLUE);
        JButton button = new JButton("click me");
        button.setBounds(100,100,200,50);
        //button监听
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                new MyJDialogDemo();
            }
        });
        jFrame.add(button);
        //绝对布局
        jFrame.setLayout(null);
        //设置关闭退出
        jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jFrame.setVisible(true);
    }
    public static void main(String[] args) {
        new JDialogDemo();
    }
}
//JDialog框
class MyJDialogDemo extends JDialog{
    public MyJDialogDemo() {
        setBounds(200,200,90,90);
        setLayout(null);
        JLabel jLabel = new JLabel("1234567890");
        jLabel.setBounds(1,1,70,70);
        add(jLabel);
        this.setVisible(true);
    }
}

3、Icon和ImageIcon

图标可以加到label和button等组件上。
要实现Icon的重绘，需要实现Icon。

Icon：

package www.xiaoxiao.com.Swing;

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

//要实现Icon的绘制需要实现Icon
public class IconDemo extends JFrame implements Icon {
    //定义一个宽和高（图标的宽和高）
    private int Width;
    private int Height;
    public static void main(String[] args) {
        new IconDemo(20,20);
    }
    public IconDemo(int width, int height) {
        Width = width;
        Height = height;
        JLabel icontest = new JLabel("icontest",this,SwingConstants.CENTER);
        //icontest.setIcon(this);
        //icontest.setHorizontalAlignment(SwingConstants.CENTER);
        setBounds(100,100,500,500);
        add(icontest);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setVisible(true);
    }
    @Override
    public void paintIcon(Component c, Graphics g, int x, int y) {
        g.fillOval(x,y,Width,Height);//x,y为位置
    }
    @Override
    public int getIconWidth() {
        return Width;
    }
    @Override
    public int getIconHeight() {
        return Height;
    }
}

ImageIcon：是Icon的一个实现类，不是接口

package www.xiaoxiao.com.Swing;

import javax.imageio.ImageIO;
import javax.swing.*;
import java.net.URL;

public class ImageIconDemo extends JFrame {
    public ImageIconDemo() throws Exception{
        URL resource = ImageIconDemo.class.getResource("tx.jpg");//获取当前目录下的文件,需要重新编译
        setBounds(100,110,500,500);
        ImageIcon imageIcon = new ImageIcon(resource);//参数为url类型
        JLabel test = new JLabel("test", imageIcon, SwingConstants.CENTER);
        add(test);
        setIconImage(ImageIO.read(resource));//JFrame设置图标
        setVisible(true);
    }
    public static void main(String[] args) throws Exception{
        new ImageIconDemo();
    }
}

4、面板Jpanel和JScrollPanel

JPanel

package www.xiaoxiao.com.Swing;

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

public class JpanelDemo extends JFrame {
    public JpanelDemo() throws HeadlessException {
        setLayout(new GridLayout(2,2,10,10));//第三、四个参数为间距
        setBounds(100,100,500,500);
        JPanel jPanel1 = new JPanel(new GridLayout(1, 2));
        JPanel jPanel2 = new JPanel(new GridLayout(2, 1));
        JPanel jPanel3 = new JPanel(new GridLayout(3, 2));
        JPanel jPanel4 = new JPanel(new GridLayout(2, 3));
        add(jPanel1);
        add(jPanel2);
        add(jPanel3);
        add(jPanel4);
        jPanel1.add(new JButton("1"));
        jPanel1.add(new JButton("1"));
        jPanel2.add(new JButton("2"));
        jPanel2.add(new JButton("2"));
        jPanel3.add(new JButton("3"));
        jPanel3.add(new JButton("3"));
        jPanel3.add(new JButton("3"));
        jPanel3.add(new JButton("3"));
        jPanel3.add(new JButton("3"));
        jPanel3.add(new JButton("3"));
        jPanel4.add(new JButton("4"));
        jPanel4.add(new JButton("4"));
        jPanel4.add(new JButton("4"));
        jPanel4.add(new JButton("4"));
        jPanel4.add(new JButton("4"));
        jPanel4.add(new JButton("4"));
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setVisible(true);
    }
    public static void main(String[] args) {
        new JpanelDemo();
    }
}

JScrollPanel

package www.xiaoxiao.com.Swing;
import javax.swing.*;
import java.awt.*;
public class JScrollPanelDemo extends JFrame {
    public JScrollPanelDemo() throws HeadlessException {
        Container container=getContentPane();
        setBounds(100,100,500,500);
        TextArea textArea = new TextArea(20, 50);
        JScrollPane jScrollPane = new JScrollPane(textArea);
        add(jScrollPane);
        setVisible(true);
    }
    public static void main(String[] args) {
        new JScrollPanelDemo();
    }
}

5、按钮

图片按钮

package www.xiaoxiao.com.Swing;

import javax.swing.*;
import java.awt.*;
import java.net.URL;

public class ImageButtonDemo extends JFrame {
    //图片按钮就是给普通迎按钮加个图片
    public ImageButtonDemo() {
        //获取容器，用JFrame尽量用Container进行add等操作
        Container contentPane = getContentPane();

        URL resource = ImageButtonDemo.class.getResource("tx.jpg");//直接获取同级目录下的图片
        ImageIcon imageIcon=new ImageIcon(resource);//创建一个ImageIcon，需要一个URL参数
        JButton but1 = new JButton();
        but1.setIcon(imageIcon);
        but1.setToolTipText("这是一个图片按钮");//设置鼠标悬浮提示
        contentPane.add(but1);


        setSize(500,400);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setVisible(true);

    }

    public static void main(String[] args) {
        new ImageButtonDemo();
    }
}

单选按钮

package www.xiaoxiao.com.Swing;

import javax.swing.*;
import java.awt.*;
import java.net.URL;

public class RadioButtonDemo extends JFrame {
    //图片按钮就是给普通迎按钮加个图片
    public RadioButtonDemo() {
        //获取容器，用JFrame尽量用Container进行add等操作
        Container contentPane = getContentPane();
        contentPane.setLayout(new GridLayout(3,1));

        JRadioButton jRadioButton01 = new JRadioButton("JRadioButton01");
        JRadioButton jRadioButton02 = new JRadioButton("JRadioButton02");
        JRadioButton jRadioButton03 = new JRadioButton("JRadioButton03");
        //单选按钮要实现多个按钮一个可选，需要添加到同一个组中
        ButtonGroup buttonGroup = new ButtonGroup();
        buttonGroup.add(jRadioButton01);
        buttonGroup.add(jRadioButton02);
        buttonGroup.add(jRadioButton03);
        contentPane.add(jRadioButton01);
        contentPane.add(jRadioButton02);
        contentPane.add(jRadioButton03);

        setSize(500,400);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setVisible(true);

    }

    public static void main(String[] args) {
        new RadioButtonDemo();
    }
}

复选框按钮

package www.xiaoxiao.com.Swing;

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

public class CheckedButtonDemo extends JFrame {
    //图片按钮就是给普通迎按钮加个图片
    public CheckedButtonDemo() {
        //获取容器，用JFrame尽量用Container进行add等操作
        Container contentPane = getContentPane();
        contentPane.setLayout(new GridLayout(3, 1));

        JCheckBox jCheckBox1= new JCheckBox("jCheckBox1");
        JCheckBox jCheckBox2= new JCheckBox("jCheckBox2");
        JCheckBox jCheckBox3= new JCheckBox("jCheckBox3");
        jCheckBox3.setToolTipText("test");
        contentPane.add(jCheckBox1);
        contentPane.add(jCheckBox2);
        contentPane.add(jCheckBox3);

        setSize(500, 400);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setVisible(true);

    }

    public static void main(String[] args) {
        new CheckedButtonDemo();
    }
}

6、列表框

下拉列表

package www.xiaoxiao.com.Swing;

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

public class JComboboxDemo extends JFrame {

    public JComboboxDemo() throws HeadlessException {
        Container contentPane = getContentPane();

        JComboBox jComboBox = new JComboBox();
        //下拉列表需要加项
        jComboBox.addItem("1");
        jComboBox.addItem("2");
        jComboBox.addItem("3");
        contentPane.add(jComboBox);
        setSize(400,500);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setVisible(true);

    }

    public static void main(String[] args) {
        new JComboboxDemo();
    }
}

列表框

package www.xiaoxiao.com.Swing;

import javax.swing.*;
import java.awt.*;
import java.util.ArrayList;
import java.util.Vector;

public class DropListDemo  extends JFrame {

    public DropListDemo() throws HeadlessException {
        Container contentPane = getContentPane();
        //String[] arrs={"","1","2"};
        //下拉列表,一般使用可动态扩容的数据类型，如Vector，这个地方不能用ArrayList，会报错，用数组可以
        Vector vector=new Vector();
        vector.add("1");
        vector.add("2");
        vector.add("3");
        JList jList = new JList(vector);
        contentPane.add(jList);
        setSize(400,500);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setVisible(true);

    }

    public static void main(String[] args) {
        new DropListDemo();
    }
}

7、文本框

文本框、密码框、文本域

package www.xiaoxiao.com.Swing;

import javafx.scene.control.PasswordField;

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

public class TextFiledDemo extends JFrame {
    public TextFiledDemo() throws HeadlessException {
        Container contentPane = getContentPane();
        contentPane.setLayout(new GridLayout(4,1));
        //文本框
        JTextField jTextField = new JTextField("1",20);
        JTextField jTextField2 = new JTextField("2");
        //密码文本框
        JPasswordField passwordField = new JPasswordField();
        //passwordField.setEchoChar('*');

        TextArea textArea = new TextArea();

        contentPane.add(jTextField);
        contentPane.add(jTextField2);
        contentPane.add(passwordField);
        contentPane.add(textArea);


        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setSize(500,500);
        setVisible(true);


    }

    public static void main(String[] args) {
        new TextFiledDemo();
    }
}

四、贪吃蛇小游戏

帧的概念：

时间片足够小，就形成了动画，一般游戏一秒30帧或60帧，拆开就是静态的图片。
要注意绘制顺序

//Snake类
import javax.swing.*;
//程序主入口
public class Snake  {
    public static void main(String[] args) {
        JFrame jFrame = new JFrame();
        jFrame.add(new GamePanel());
        jFrame.setResizable(false);
        jFrame.setBounds(100,100,920,800);
        jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        jFrame.setVisible(true);
    }
}



//面板绘制类GamePanel
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;

import static java.awt.Font.BOLD;
import static java.awt.Font.ITALIC;

//面板，所有操作均在面板上实现
public class GamePanel extends JPanel implements KeyListener, ActionListener {
    //定义小蛇数据结构
    int length;//小蛇长度
    int snakeX[];//小蛇的X坐标位置数据
    int snakeY[];//小蛇的Y坐标位置数据
    String orientation;//蛇头方向
    boolean status;//定义游戏状态：开始-停止
    boolean fail;//定义失败状态
    //食物坐标
    int foodx;
    int foody;
    Random random;
    int score;
    Timer timer = new Timer(100, this);//创建一个定时器

    public GamePanel() {
        init();
        //设置焦点，默认为false
        setFocusable(true);
        //加键盘监听
        addKeyListener(this);
    }

    //初使化
    private void init() {
        length = 3;//默认长度为3
        score=0;//分数
        snakeX = new int[34];//小蛇的X坐标位置数据
        snakeY = new int[26];//小蛇的Y坐标位置数据
        snakeX[0] = 125;
        snakeY[0] = 100;//小蛇头
        snakeX[1] = 100;
        snakeY[1] = 100;//小蛇身体
        snakeX[2] = 75;
        snakeY[2] = 100;//小蛇身体
        orientation = "right";//默认方向为向右
        status = false;
        timer.start();//计时器开始
        random = new Random();//生成食物用
        //绘制食物
        foodx = 25 + 25 * random.nextInt(33);
        foody = 75 + 25 * random.nextInt(25);
        fail = false;
    }

    //绘制方法，显示时自动调用
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);//有清屏功能，如果不清屏会闪烁
        //绘制静态面板
        setBackground(Color.WHITE);
        g.setColor(Color.CYAN);
        //g.fillRect(25, 15, 850, 55);//游戏界面面板
        //给一个组件绘制Icon
        Data.headerIcon.paintIcon(this, g, 0, 15);//头部广告栏绘制
        g.setColor(Color.BLUE);
        g.setFont(new Font("宋体", BOLD | ITALIC, 32));
        g.drawString("小狗平招商位", 75, 55);
        g.setColor(Color.RED);
        g.setFont(new Font("宋体", BOLD | ITALIC, 16));
        g.drawString("小蛇长度:"+length, 750, 45);
        g.drawString("得分:"+score, 750, 58);

        g.setColor(Color.BLACK);
        g.fillRect(25, 75, 850, 650);//游戏界面面板
        //小蛇静态绘制
        //通过循环绘制身体
        for (int i = 1; i  0; i--) {
                //前一项赋值给后一项
                snakeX[i] = snakeX[i-1];
                snakeY[i] = snakeY[i-1];
            }
            switch (orientation) {
                case "right"://向右
                    snakeX[0] = snakeX[0] + 25;//头动起来
                    if (snakeX[0] > 850) {
                        snakeX[0] = 25;
                    }
                    break;
                case "left"://向左
                    snakeX[0] = snakeX[0] - 25;//头动起来
                    if (snakeX[0] < 25) {
                        snakeX[0] = 850;
                    }
                    repaint();
                    break;
                case "up"://向上
                    snakeY[0] = snakeY[0] - 25;//头动起来
                    if (snakeY[0] < 75) {
                        snakeY[0] = 700;
                    }
                    repaint();
                    break;
                case "down"://向下
                    snakeY[0] = snakeY[0] + 25;//头动起来
                    if (snakeY[0] > 700) {
                        snakeY[0] = 75;
                    }
                    break;
            }

            //判断小蛇死亡
            for (int j = 1; j < length; j++) {
                if (snakeX[0]==snakeX[j] && snakeY[0]==snakeY[j]){
                    fail=true;
                    repaint();
                }
            }
            if (snakeX[0] == foodx && snakeY[0] == foody) {
                //重绘食物
                foodx = 25 + 25 * random.nextInt(33);
                foody = 75 + 25 * random.nextInt(25);
                length++;//小蛇长度+1
                snakeX[length-1]=snakeX[length-2];
                snakeY[length-1]=snakeY[length-2];
                score+=10;

            }

            repaint();
        }

    }
}


//静态资源类Data
import javax.swing.*;
import java.awt.*;
import java.net.URL;

public class Data {
    //Data.class.getResource这个路径是src的路径
    public static URL header =Data.class.getResource("/static/header.png");
    public static ImageIcon headerIcon=new ImageIcon(header);
    public static URL up =Data.class.getResource("/static/up.png");
    public static ImageIcon upIcon=new ImageIcon(up);
    public static URL down =Data.class.getResource("/static/down.png");
    public static ImageIcon downIcon=new ImageIcon(down);
    public static URL left =Data.class.getResource("/static/left.png");
    public static ImageIcon leftIcon=new ImageIcon(left);
    public static URL right =Data.class.getResource("/static/right.png");
    public static ImageIcon rightIcon=new ImageIcon(right);
    public static URL food =Data.class.getResource("/static/food.png");
    public static ImageIcon foodIcon=new ImageIcon(food);
    public static URL body =Data.class.getResource("/static/body.png");
    public static ImageIcon bodyIcon=new ImageIcon(body);
}

javaGUI