我是gui java的新手，我一直在尝试重新创建名为"jump it"(http://www.crazygames.com/game/jump-it(的游戏，我目前正在制作随机矩形让我的角色跳上去。但是，我运行了代码，没有错误，但是我制作的矩形没有显示。我在下面附加了我的代码，对此有点抱歉。
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.util.Random;
import java.util.TimerTask;
class GuiGame{
public static void main(String args[]) {
JFrame f = new JFrame("RUN - Christine & Esther"); //title of frame
Container cont = f.getContentPane(); // get container - top of the frame
cont.setLayout(new BorderLayout());
BtnActPanel bp = new BtnActPanel(); // create an object of our game panel
cont.add(bp, BorderLayout.CENTER );
f.setVisible(true);
f.setSize(975,613); //size of frame
}
}
class Rectangle{
static Random r = new Random();
static int upperX = 100;
static int lowerX = 20;
static int upperY = 550;
static int lowerY = 450;
static int minWidth = 200;
static int maxWidth = 600;
static int minHeight = 40;
static int maxHeight = 140;
static int x = 0, y = 0, w = 0, h = 0, check = 0;
public Rectangle(){
check++;
int x = 650 + 50*check;
int y = r.nextInt(upperY-lowerY + 1) + lowerY; // from 450 to 550
int w = r.nextInt(maxWidth-minWidth + 1) + minWidth; // from 200 to 600
int h = r.nextInt(maxHeight - minHeight + 1) + minHeight; // from 40 to 140
}
public int getx(){
return x;
}
public int gety(){
return y;
}
public int getw(){
return w;
}
public int geth(){
return h;
}
}
class BtnActPanel extends JPanel implements ActionListener{
//variables
private JButton b1, b2, b3;
private JPanel background;
private JPanel game;
private Timer t, timer;
private int x = 0, check1 = 0, index = 0, x1 = 650, count2 = 0,
y2 = (int)(Math.random()*100)+40, y1 = (int)(Math.random()*100)+450,
x2 = (int)(Math.random()*600)+200, xaxis = 0, yaxis = 0, w = 0, h = 0, count = 0;
private ImageIcon []arrImage;
private boolean check2;
private static ImageIcon icon, exitButton, startButton, questionButton, b, instruct, c ;
public BtnActPanel(){
c = new ImageIcon("character.png"); // constructor
t = new Timer (100,this);
arrImage = new ImageIcon[2];
arrImage[0] = new ImageIcon("character.png");
arrImage[1] = new ImageIcon("character2.png");
startButton = new ImageIcon("startButton.png");//start button image
questionButton = new ImageIcon("QuestionButton.png"); //question button image
exitButton = new ImageIcon("exitButton.png"); //exit button image
icon = new ImageIcon("Title.jpg");//title image
b1 = new JButton(questionButton); // creates first button
//only shows button image with borders
b1.setOpaque(false);
b1.setContentAreaFilled(false);
b1.setBorderPainted(false);
b1.setFocusPainted(false);
b2 = new JButton(startButton);// creates second button
//only shows button image with borders
b2.setOpaque(false);
b2.setContentAreaFilled(false);
b2.setBorderPainted(false);
b2.setFocusPainted(false);
b3 = new JButton(exitButton);// creates third button
//only shows button image with borders
b3.setOpaque(false);
b3.setContentAreaFilled(false);
b3.setBorderPainted(false);
b3.setFocusPainted(false);
//adds buttons to code
this.add(b1);
this.add(b2);
this.add(b3);
b1.addActionListener(this);
b2.addActionListener(this);
b3.addActionListener(this);
}// end of constructor
public void actionPerformed(ActionEvent e) { //checks which button the user presses and performs actions based off choice
if(e.getSource() == b1){
check1 = 2;
this.remove(b1);
this.remove(b3);
repaint();
instruct = new ImageIcon("Instructions.jpg");
}
else if (e.getSource() == b2){
t.start();
check1 = 1;
this.remove(b1);
this.remove(b2);
this.remove(b3);
repaint();
b = new ImageIcon("toskyline.png");
}
else if (e.getSource() == b3){
JOptionPane.showMessageDialog(null, "This is an exit button, hope you enjoyed the game! :)", "Exit message",JOptionPane.WARNING_MESSAGE ); //shows exit message
System.exit(0);//exits program
}
else if (e.getSource() == t){
if (index == 0){
index = 1;
c = arrImage[1];
}
else{
index = 0;
c = arrImage[0];
}
if(count%50 == 0 && count >= 50){
Rectangle obstacle = new Rectangle();
int xaxis = obstacle.getx();
int yaxis = obstacle.gety();
int w = obstacle.getw();
int h = obstacle.geth();
xaxis = xaxis - 10;
count2 = 1;
}
x = x - 10;
x1 = x1 - 10;
repaint();
}
}
public void paintComponent(Graphics g){//this method draws and paints images and icons based on the user decisions
super.paintComponent(g);
if(check1 == 0)[enter image description here][1]
g.drawImage(icon.getImage(),0,0,null);
if(check1 == 1){
g.drawImage(b.getImage(),0,0,null);
g.setColor(Color.black);
g.fillRect(x,495, 500, 35);
g.fillRect(x1, y1, x2, y2);
count++;
System.out.println(count);
if(count2 == 1){
g.fillRect(xaxis, yaxis, w, h);
count2 = 0;
}
g.drawImage(c.getImage(), 100, 460, null);
}
if(check1 == 2)
g.drawImage(instruct.getImage(),0,0,null);
b1.setBounds(320, 350, 100, 100);
b2.setBounds(420, 350, 100, 100);
b3.setBounds(520, 350, 100, 100);
}
}//end of class
使用您的范围，我做了一个演示。
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
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.SwingUtilities;
import javax.swing.Timer;
public class Demo extends JPanel implements ActionListener {
final static int height = 800;
final static int width = 800;
final static String title = "title";
JFrame frame = new JFrame("default title");
Timer timer;
static Random r = new Random();
static int upperX = 100;
static int lowerX = 20;
static int upperY = 550;
static int lowerY = 450;
static int minWidth = 200;
static int maxWidth = 600;
static int minHeight = 40;
static int maxHeight = 140;
List<MyRectangle> rectangles = new ArrayList<>();
public static void main(String[] args) {
SwingUtilities
.invokeLater(() -> new Demo().start());
}
public Demo() {
frame.setDefaultCloseOperation(
JFrame.EXIT_ON_CLOSE);
frame.add(this);
frame.setPreferredSize(
new Dimension(width, height));
setBackground(Color.WHITE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public void start() {
timer = new Timer(0, this);
timer.setDelay(1000);
timer.start();
}
public void actionPerformed(ActionEvent ae) {
rectangles.add(createRectangle());
repaint();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
for (MyRectangle r : rectangles) {
g2d.setColor(Color.black);
g2d.drawRect(r.x, r.y, r.width, r.height);
g2d.setColor(r.color);
g2d.fillRect(r.x+1, r.y+1, r.width-1,r.height-1);
}
g2d.dispose();
}
Color[] colors = {Color.RED, Color.BLUE, Color.GREEN, Color.ORANGE, Color.GRAY};
int color = 0;
public MyRectangle createRectangle() {
int y = r.nextInt(upperY - lowerY + 1) + lowerY; // from 450 to 550
int w = r.nextInt(maxWidth - minWidth + 1)
+ minWidth; // from 200 to 600
int h = r.nextInt(maxHeight - minHeight + 1)
+ minHeight; // from 40 to 140
int x = r.nextInt(upperX - lowerX + 1) + lowerX;
Color c = colors[color++ % colors.length];
return new MyRectangle(c, x, y, w, h);
}
class MyRectangle extends Rectangle {
Color color;
MyRectangle(Color c, int x, int y, int w, int h) {
super(x, y, w, h);
this.color = c;
}
}
}
这将扩展 JDK 类矩形并向子类添加一个色域。它显示一个新的矩形。