在窗口中设置三个“圆形”“扇形”“矩形”按钮，点击按钮，将图形变为相应的形状（实心），设置三个“红色”“绿色”“蓝色”滚动条，滑动滚动条变换图形的颜色，设置一个控制左右移动的滚动条，点击滚动条变换图形
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2022-05-30 18:29:48
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import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Dictionary;
import java.util.Hashtable;
public class Main {
public static void main(String[] args) {
/*
* 在 AWT 的事件队列线程中创建窗口和组件, 确保线程安全,
* 即 组件创建、绘制、事件响应 需要处于同一线程。
*/
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
// 创建窗口对象
MyFrame frame = new MyFrame();
// 显示窗口
frame.setVisible(true);
}
});
}
/**
* 窗口
*/
public static class MyFrame extends JFrame {
public static final String TITLE = "Java图形绘制";
public static final int WIDTH = 500;
public static final int HEIGHT = 400;
public MyFrame() {
super();
initFrame();
}
private void initFrame() {
// 设置 窗口标题 和 窗口大小
setTitle(TITLE);
setSize(WIDTH, HEIGHT);
// 设置窗口关闭按钮的默认操作(点击关闭时退出进程)
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
// 把窗口位置设置到屏幕的中心
setLocationRelativeTo(null);
JPanel main = new JPanel(new BorderLayout());
final MyPanel pic = new MyPanel(Color.BLACK,80,-1,0);
main.add(pic,BorderLayout.CENTER);
JPanel btn_panel = new JPanel(new GridLayout(3, 3));
JButton btn_circle = new JButton("圆形");
btn_circle.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
pic.setType(0);
pic.updateUI();
}
});
JButton btn_sx = new JButton("扇形");
btn_sx.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("扇形");
pic.setType(1);
pic.updateUI();
}
});
JButton btn_rec = new JButton("矩形");
btn_rec.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
pic.setType(2);
pic.updateUI();
}
});
JButton btn_red = new JButton("红色");
btn_red.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
pic.setColor(Color.RED);
pic.updateUI();
}
});
JButton btn_green = new JButton("绿色");
btn_green.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
pic.setColor(Color.GREEN);
pic.updateUI();
}
});
JButton btn_blue = new JButton("蓝色");
btn_blue.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
pic.setColor(Color.BLUE);
pic.updateUI();
}
});
JButton btn_plus = new JButton("变大");
btn_plus.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
pic.setSize(150);
pic.updateUI();
}
});
JButton btn_small = new JButton("变小");
btn_small.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
pic.setSize(50);
pic.updateUI();
}
});
btn_panel.add(btn_circle);
btn_panel.add(btn_sx);
btn_panel.add(btn_rec);
btn_panel.add(btn_red);
btn_panel.add(btn_green);
btn_panel.add(btn_blue);
btn_panel.add(btn_plus);
btn_panel.add(btn_small);
main.add(btn_panel,BorderLayout.NORTH);
JSlider slider = new JSlider(JSlider.VERTICAL,0,2,1);
slider.setPaintTicks(true);
slider.setSnapToTicks(true);// 设置滚动条只停留在有刻度的地方
slider.setMinorTickSpacing(1);
slider.setMajorTickSpacing(1);
slider.setPaintLabels(true);
slider.setInverted(true);
Dictionary<Integer, Component> labels = new Hashtable<Integer, Component>();
labels.put(0, new JLabel("红色"));
labels.put(1, new JLabel("绿色"));
labels.put(2, new JLabel("蓝色"));
slider.setLabelTable(labels);
slider.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
JSlider source = (JSlider)e.getSource();
switch(source.getValue()){
case 0:pic.setColor(Color.RED);break;
case 1:pic.setColor(Color.GREEN);break;
case 2:pic.setColor(Color.BLUE);break;
}
pic.updateUI();
}
});
main.add(slider,BorderLayout.EAST);
JSlider slider2 = new JSlider(JSlider.HORIZONTAL,0,250,1);
slider2.setPaintTicks(true);
slider2.setSnapToTicks(true);// 设置滚动条只停留在有刻度的地方
slider2.setPaintLabels(true);
slider2.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
JSlider source = (JSlider)e.getSource();
int sub = source.getValue();
pic.setSub(sub);
pic.updateUI();
}
});
main.add(slider2,BorderLayout.SOUTH);
setContentPane(main);
}
}
/**
* 内容面板
*/
public static class MyPanel extends JPanel {
private Color color;
private int size;
private int type;
private int sub;
public MyPanel(Color color,int size,int type,int sub) {
this.color = color;
this.size = size;
this.type = type;
this.sub = sub;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
draw(g,type);
}
private void draw(Graphics g,int type){
if(type == 0){
drawCircle(g, color);
}else if(type == 1){
drawArc(g, color);
}else if(type == 2){
drawRect(g, color);
}
}
private void drawCircle(Graphics g,Color color){
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(color);
// 2. 绘制一个圆: 圆的外切矩形 左上角坐标为(120, 20), 宽高为100
g2d.fillArc(30+ sub, 20, size, size, 0, 360);
g2d.dispose();
}
/**
* 2. 矩形 / 多边形
*/
private void drawRect(Graphics g,Color color) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(color);
g2d.fillRect(30+ sub, 20, size, size+20);
g2d.dispose();
}
/**
* 3. 圆弧 / 扇形
*/
private void drawArc(Graphics g,Color color) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(color);
// 3. 填充一个扇形
g2d.fillArc(30 + sub, 20, size, size, 90, 170);
g2d.dispose();
}
public void setColor(Color color) {
this.color = color;
}
public void setSize(int size) {
this.size = size;
}
public void setType(int type) {
this.type = type;
}
public void setSub(int sub){
this.sub = sub;
}
}
}