我需要做的是存储＆＃34;障碍物＆＃34;的不同对象。数组中的超类，然后执行与我有一个相同的操作。所以我需要能够绘制所有对象并使它们与球类碰撞。
所以我试图将一个对象的所有实例放在一个for循环的数组中，然后我尝试绘制它们。但如果对象存储在数组中，我无法弄清楚如何使用对象上的函数。
我试着这样做：
for(int i = 0;i<objects.length;i++){
objects[0].paint(g);
}
但是＆＃34;油漆（g）＆＃34;部分只是用红色突出显示，但它不起作用。
如果有人能帮助我，我真的很开心！我之前没有将对象存储在数组中，所以我有点无能为力。
我也试过像这样制作for循环：
if(i>=1 && i<15){
Obstacle star = new StarObstacle(rand.nextInt(400),rand.nextInt(400));
objects[i]= star;
star.paint(g);
}
这里他们实际上出现了，但是星星只是在屏幕上飞来飞去，所以必须始终改变x和y值。
编辑：抱歉意外添加了整个代码，而不仅仅是我需要帮助的部分。 它是Main（int x，int y）{}范围
中的for循环package com.company;
import javax.swing.*;
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.Random;
public class Main extends JPanel implements KeyListener {
Ball b;
TriangleObstacle o;
BorderObstacle border;
StarObstacle s;
Player player;
int bounceCount=0;
Object[] objects;
Random rand = new Random();
Main(int width, int height) {
//create a new black ball at the center of the screen
b = new Ball(width*0.5f, height*0.5f, 3, 0,0,0);
//make a border around the window
border = new BorderObstacle(width, height);
objects = new Object[30];
//setup a triangle obstacle
o = new TriangleObstacle(width*0.3f, height*0.7f, 200, 50);
s = new StarObstacle(400,300);
player = new Player();
this.addKeyListener(this);
this.setFocusable(true); //needed to make
for(int i = 0; i < objects.length;i++){
if(i==0){
objects[0]= new Player();
}
if(i>=1 && i<15){
objects[i]= new StarObstacle(rand.nextInt(400),rand.nextInt(400));
}
if(i>15){
objects[i]= new TriangleObstacle(30,30,rand.nextInt(400),rand.nextInt(400));
}
}
}
public void update() {
//move over all obstacles and check whether they should bounce the ball
border.bounceBall(b);
o.bounceBall(b);
s.bounceBall(b);
if(player.bounceBall(b)){
bounceCount++;
}
//move ball based on speed and location
b.move();
player.move(); //updates my player object.
this.repaint(); //runs the paint method on the object
}
@Override
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.setFont(new Font("TimesRoman", Font.PLAIN, 20));
g.drawString("Amount of bounces on Player: " + bounceCount, 300, 100);
b.paint(g);
o.paint(g);
s.paint(g);
player.paint(g);
border.paint(g);
}
public static void main(String[] args) {
int width = 800;
int height = 600;
JFrame frame = new JFrame("Pinball"); //create a new window and set title on window
frame.setSize(width, height); //set size of window
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //set the window to close when the cross in the corner is pressed
Main m = new Main(width,height-22); //-22 to account for menubar height //create a new object and runs constructor for initial setup of the program
frame.add(m); //add the content of the object to the window
frame.setVisible(true); //make the window visible
while (true) { //keep running a loop
//each time the loop is run do
m.update(); //run the update method on the object
try {
Thread.sleep(10); //stops this part of the program for 10 milliseconds to avoid the loop locking everything. Now the screen has time to update content etc.
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
@Override
public void keyTyped(KeyEvent e) {
}
@Override
public void keyPressed(KeyEvent e) {
int code = e.getKeyCode(); //gets input as keycode.
if(code==KeyEvent.VK_RIGHT){
player.setRight(true); //sets the movement for right to true, making it move by 5 pixels in the positive direction, for each update.
player.setLeft(false);
}
if(code==KeyEvent.VK_LEFT){
player.setLeft(true);
player.setRight(false);
}
}
@Override
public void keyReleased(KeyEvent e) { //keyReleased setting them to false to prevent the object to keep moving.
int code = e.getKeyCode();
if(code==KeyEvent.VK_RIGHT){
player.setRight(false);
}
if(code==KeyEvent.VK_LEFT){
player.setLeft(false);
}
}
}
答案 0 :(得分：0)
这：
for(int i = 0;i<objects.length;i++){
objects[0].paint(g);
}
由于您始终访问索引0，因此无法实现您的目标。
试试这个：
for(int i = 0;i<objects.length;i++){
objects[i].paint(g);
}
这允许您访问和绘制由i表示的索引上的每个对象。我不能保证这会解决问题，但它是 问题。
答案 1 :(得分：0)
您需要强制转换对象并使用正确的索引：
objects[0].paint(g);
应该是
((Observer)objects[i]).paint(g);
然而，这完全是错误的做法。请阅读java泛型。 http://docs.oracle.com/javase/tutorial/java/generics/
您应该使用List或其他具有上限通配符的集合，例如
List<? extends Observer>
这将提供类型安全。
答案 2 :(得分：0)
您需要在“Player”，“StarObstacle”，“TriangleObstacle”等类中编写自己的方法绘画（图形g）。
类似的东西：
class TriangleObstacle extend Obstacle {
public paint(Graphics g) {
g.drawPolygon (...);
}
}
另外，避免使用Objects（Objects []）数组。更好地使用你的超类障碍阵列（障碍[] myObstacle =新障碍[30];
并且不要将Player对象放在Obstacle数组中，这是没有意义的。
在决赛中你可以：
Obstacle[] myObstacles = new Obstacle[30];
Player player = new Player();
....
for (Obstacle obstacle : myObstacles) {
obstacle.paint(g);
}
player.paint(g);
答案 3 :(得分：0)
您必须创建一个Obstacles而不是objects的数组，在Obstacles界面中添加一个名为paint()的方法定义。然后，您必须在每个Obstacles实现中覆盖paint()方法。当你在数组的对象中调用paint方法时，它将调用相应的方法。
答案 4 :(得分：0)
您可以将对象放在列表中而不是数组吗？有点像...
List<Obstacle> someList = [however you populate your array, just populate the list instead];
for(int i = 0; i<somelist.length; i++) {
someList.get(i).paint(g);
}