问题：
如果在JPanel上画得太远，我怎么再画一个圆
薄鸿远
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.geom.Rectangle2D;
import java.util.Random;
import javax.swing.JPanel;
import javax.swing.Timer;
public class keyExample extends JPanel implements ActionListener, KeyListener {
private Circle[] circles = new Circle[7];
Timer t = new Timer(5, this);
//current x and y
double x = 150, y = 200;
double changeX = 0, changeY = 0;
private Circle c1, c2, c3, c4, c5, c6, c7, circleone;
private int circlex = 10, circley = 0; // makes initial starting point of circles 0
private int newCirclex = 0, newCircley = 0;
private javax.swing.Timer timer2;
private Random num = new Random();
private int s = num.nextInt(8);
public keyExample() {
t.start();
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
Random num = new Random();
Random colors = new Random();
Color color1 = new Color(colors.nextInt(256), colors.nextInt(256), colors.nextInt(256));
Color color2 = new Color(colors.nextInt(256), colors.nextInt(256), colors.nextInt(256));
Color color3 = new Color(colors.nextInt(256), colors.nextInt(256), colors.nextInt(256));
Color color4 = new Color(colors.nextInt(256), colors.nextInt(256), colors.nextInt(256));
Color color5 = new Color(colors.nextInt(256), colors.nextInt(256), colors.nextInt(256));
Color color6 = new Color(colors.nextInt(256), colors.nextInt(256), colors.nextInt(256));
Color color7 = new Color(colors.nextInt(256), colors.nextInt(256), colors.nextInt(256));
int radius1 = num.nextInt(40);
int radius2 = num.nextInt(20);
int radius3 = num.nextInt(25);
int radius4 = num.nextInt(45);
int radius5 = num.nextInt(15);
int radius6 = num.nextInt(40);
int radius7 = num.nextInt(50);
if (radius1 < 5) {
radius1 = 10;
} else if (radius2 < 5) {
radius2 = 10;
} else if (radius3 < 5) {
radius3 = 10;
} else if (radius4 < 5) {
radius4 = 10;
} else if (radius5 < 5) {
radius5 = 10;
} else if (radius6 < 5) {
radius6 = 10;
} else if (radius7 < 5) {
radius7 = 10;
} else {
}
c1 = new Circle(circlex, circley, radius1, color1);
c2 = new Circle(circlex + 70, circley, radius2, color2);
c3 = new Circle(circlex + 150, circley, radius3, color3);
c4 = new Circle(circlex + 220, circley, radius4, color4);
c5 = new Circle(circlex + 270, circley, radius5, color5);
c6 = new Circle(circlex + 340, circley, radius6, color6);
c7 = new Circle(circley + 410, circley, radius7, color7);
circles[0] = c1;
circles[1] = c2;
circles[2] = c3;
circles[3] = c4;
circles[4] = c5;
circles[5] = c6;
circles[6] = c7;
timer2 = new javax.swing.Timer(33, new MoveListener());
timer2.start();
}
public void NewCircle() {
for (int i = 0; i < circles.length; i++) {
Random num = new Random();
Random colors = new Random();
Color color = new Color(colors.nextInt(256), colors.nextInt(256), colors.nextInt(256));
int radius = num.nextInt(40);
if (radius < 5) {
radius = radius + 10;
} else {
}
circles[i] = new Circle(circlex, circley, radius, color);
}
}
public void replaceCircle() {
int height = getHeight();
newCircley = newCircley + s;
circley = newCircley;
Random num = new Random();
int radius = num.nextInt(34);
Random colors = new Random();
Color color = new Color(colors.nextInt(256), colors.nextInt(256), colors.nextInt(256));
if (circley > height) {
c1 = new Circle(10, 0, radius, color);
} else {
}
}
public void createCircle() {
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.BLUE);
g2.fill(new Rectangle2D.Double(x, y, 40, 40));
for (int i = 0; i < circles.length; i++) {
circles[i].fill(g);
}
}
public void actionPerformed(ActionEvent e) {
repaint();
x += changeX;
y += changeY;
changeX = 0;
changeY = 0;
}
public void up() {
if (y != 0) {
changeY = -3.5;
changeX = 0;
}
}
public void down() {
if (y <= 350) {
changeY = 3.5;
changeX = 0;
}
}
public void left() {
if (x >= 0) {
changeX = -3.5;
changeY = 0;
}
}
public void right() {
if (x <= 550) {
changeX = 3.5;
changeY = 0;
}
}
private class MoveListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
Random speed = new Random();
int s2 = speed.nextInt(12);
int s3 = speed.nextInt(4);
int s4 = speed.nextInt(20);
int s5 = speed.nextInt(7);
int s6 = speed.nextInt(5);
int s7 = speed.nextInt(8);
c1.move(0, s);
c2.move(0, s2);
c3.move(0, s3);
c4.move(0, s4);
c5.move(0, s5);
c6.move(0, s6);
c7.move(0, s7);
repaint();
}
}
public void keyPressed(KeyEvent e) {
int code = e.getKeyCode();
if (code == KeyEvent.VK_UP) {
up();
}
if (code == KeyEvent.VK_DOWN) {
down();
}
if (code == KeyEvent.VK_RIGHT) {
right();
}
if (code == KeyEvent.VK_LEFT) {
left();
}
}
public void keyTyped(KeyEvent e) {
}
public void keyReleased(KeyEvent e) {
}
public static void main(String[] args) {
new keyExample();
}
}
import java.awt.*;
公共阶级圈{
private int centerX, centerY, radius, coord;
private Color color;
public Circle(int x, int y, int r, Color c) {
centerX = x;
centerY = y;
radius = r;
color = c;
}
public void draw(Graphics g) {
Color oldColor = g.getColor();
g.setColor(color);
g.drawOval(centerX - radius, centerY - radius, radius * 2, radius * 2);
g.setColor(oldColor);
}
public void fill(Graphics g) {
Color oldColor = g.getColor();
g.setColor(color);
g.fillOval(centerX - radius, centerY - radius, radius * 2, radius * 2);
g.setColor(oldColor);
}
public boolean containsPoint(int x, int y) {
int xSquared = (x - centerX) * (x - centerX);
int ySquared = (y - centerY) * (y - centerY);
int RadiusSquared = radius * radius;
return xSquared + ySquared - RadiusSquared <= 0;
}
public void move(int xAmount, int yAmount) {
centerX = centerX + xAmount;
centerY = centerY + yAmount;
}
}
共有1个答案
淳于枫
更好的解决方案是为循环提供一些方法来确定当它移动到边界之外时应该做什么，然而，代码太复杂了，我用了这个...
首先将getBounds方法添加到circle类中...
public Rectangle getBounds() {
int x = centerX - radius;
int y = centerY - radius;
return new Rectangle(x, y, radius * 2, radius * 2);
}
这将提供关于圆圈有多大和在哪里的信息...
public void checkBounds(Circle circle) {
int height = getHeight();
Rectangle bounds = circle.getBounds();
if (bounds.y + bounds.height > height) {
circle.move(0, -(height) + bounds.height);
}
}
c1.move(0, s);
checkBounds(c1);
诸如此类...
用快速和快速的示例更新
所以，这是一个快速的例子，我一直在努力...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class DropCircles {
public static void main(String[] args) {
new DropCircles();
}
public DropCircles() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public static class TestPane extends JPanel {
protected static final int MAX_CIRCLES = 7;
private List<Circle> circles;
private Random rnd = new Random();
public TestPane() {
circles = new ArrayList<>(MAX_CIRCLES);
Timer timer = new Timer(40, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
while (circles.size() < MAX_CIRCLES) {
circles.add(createCircle());
}
List<Circle> purge = new ArrayList<>(MAX_CIRCLES);
for (Circle circle : circles) {
Point p = circle.getLocation();
p.y += circle.getYDelta();
if (p.y > getHeight()) {
purge.add(circle);
} else {
circle.setLocation(p);
}
}
circles.removeAll(purge);
repaint();
}
});
timer.start();
}
protected Circle createCircle() {
int x = rnd.nextInt(getWidth());
int radius = 5 + rnd.nextInt(45);
int speed = 1 + rnd.nextInt(8);
if (x + radius > getWidth()) {
x = getWidth() - radius;
}
Circle circle = new Circle(radius, new Color(rnd.nextInt(255), rnd.nextInt(255), rnd.nextInt(255)));
circle.setLocation(x, 0);
circle.setYDelta(speed);
return circle;
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
for (Circle circle : circles) {
circle.paint(g);
}
g2d.dispose();
}
}
public static class Circle {
private final int radius;
private final Color color;
private int x;
private int y;
private int yDelta;
public Circle(int radius, Color color) {
this.radius = radius;
this.color = color;
}
public void setLocation(int x, int y) {
this.x = x;
this.y = y;
}
public void setLocation(Point p) {
setLocation(p.x, p.y);
}
public Point getLocation() {
return new Point(x, y);
}
public void setYDelta(int yDelta) {
this.yDelta = yDelta;
}
public int getYDelta() {
return yDelta;
}
public void paint(Graphics g) {
g.setColor(color);
g.fillOval(x, y, radius, radius);
}
}
}
类似资料：
-
我正在尝试使用“绘画组件”或“绘画”来显示我添加到框架中的 JPanel 上的形状。我尝试了许多教程，但它们似乎只是使整个框架成为“面板”。我想添加到我的JPanel中，我已经添加到我的框架中。 这是我到目前为止的代码： 我不想把框架做成一个巨大的面板并在上面绘图，因为我正在添加单选按钮来创建特定的形状，我只是在网上看到人们向你展示如何为整个框架扩展JPanel。我问的是不可能的吗？
-
问题内容： 我有一个JPanel，我为此设置了一些图像作为背景。我需要在图像上方绘制一堆圆圈。现在，圆将基于某个坐标x，y进行定位，其大小将基于某个整数大小。这就是我上课的时间。 如何创建可以执行此操作的方法？ 问题答案： 您的方法可能与此类似，其中您也使用一个类来容纳所有圆和绘制例程：
-
我试着在画布里放一幅画。但就是没有出现。我谷歌了一下，看看哪里出了问题。不幸的是，我还是解决不了。这是我的代码 这是css文件
-
我想为我画的画举办一个活动。 目前，我用wxPython绘制矩形， 我想连接按钮一样的链接。 有可能吗？ 如果可能的话，请给我建议。 下面是我的代码。
-
本文向大家介绍python实现在一个画布上画多个子图，包括了python实现在一个画布上画多个子图的使用技巧和注意事项，需要的朋友参考一下 matplotlib 是可以组合许多的小图, 放在一张大图里面显示的. 使用到的方法叫作 subplot. 均匀画图 使用import导入matplotlib.pyplot模块, 并简写成plt. 使用plt.figure创建一个图像窗口. 使用plt.sub
-
我的印象是，在JFrame上放置图形需要画布或JPanel，但我之前看到一个视频，其中一个人在扩展JFrame时使用绘画（graphics g），而没有制作面板或画布。如果是这样的话，为什么人们要费心制作画布或JPanel呢？