Java线程和graphics2d [英] Java thread and graphics2d
问题描述
我需要提示如何使我的程序正常运行.我创建了一个从JComponent扩展的类.我还设法使整个面板变成白色.现在，我试图使我的线程Wolf将被绘制在JCOmponent上并将移动一次.不幸的是我的代码不起作用，我认为这是因为没有在白板上画狼.如何更改程序以使其起作用.我将不胜感激.
i need a hint how to make my program to work properly. I created a class that extends from JComponent. I also managed to make the whole panel of white colors. Now i am trying to make that my thread Wolf will be painted on the JCOmponent and will move one time. Unfortunately my code dont works and i think its because wolf is not being painted on the white board. How to change the program to make it work. I will be grateful for help.
public class Plansza extends JComponent implements ActionListener {
static int width = 500;
static int height = 500;
Ellipse2D wolf;
Ellipse2D hare;
// size of frame n x m (width,height)
public Dimension getPreferredSize(){
return new Dimension(width,height);
}
protected void paintComponent(Graphics g){
Graphics2D g2 = (Graphics2D) g;
//draw a background
g.setColor(Color.WHITE);
g.fillRect(0, 0, width, height);
}
class Wilk implements Runnable{
private int x;
private int y;
//when creating a thread we get a first position of wolf
Wilk(int posx, int posy){
x=posx;
y=posy;
}
protected void paintComponent(Graphics g){
Graphics2D g2 = (Graphics2D) g;
//draw a wolf
g.setColor(Color.BLUE);
wolf = new Ellipse2D.Double(x,y, 10, 10);
g2.fill(wolf);
}
public void run() {
x=x+5;
y=y+5;
repaint();
}
}
public static void main( final String args[]) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame window = new JFrame("Wilki vs Zajace");
Plansza p = new Plansza();
window.add(p);
window.pack();
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setLocationRelativeTo(null);
window.setVisible(true);
// Timer t = new Timer(10,p); //action listener referred to Plansza(1 cycle every 100miliseconds)
// t.start();
Wilk wolf = new Wilk(10,10);
Thread myWolf = new Thread(wolf);
myWolf.start();
}
});
}
@Override
public void actionPerformed(ActionEvent e) {
}
}
推荐答案
首先介绍一下在AWT和Swing中绘画有关在Swing中如何进行绘画的详细信息.
Start by talking a look at Performing Custom Painting and Painting in AWT and Swing for details about how painting is performed in Swing.
请参阅 Swing中的并发，以了解有关处理的详细信息摆动线程.
Take a look at Concurrency in Swing for details about dealing with Swing a threads.
基本上，将仅绘制显示的容器上的组件.这意味着只有您的Plansza会被绘制，只有在将它添加到(直接或以其他方式)诸如JFrame之类并且使JFrame可见的情况下.
Basically, only a component on a displayed container will be painted. This means that only your Plansza will be painted, but only when it's added to a (directly or otherwise) something like JFrame and the JFrame is made visible.
这意味着Wilk永远不能被绘制，因此它的paintComponent方法变得毫无意义(在这种情况下)
This means that Wilk can never be painted and therefore it's paintComponent method becomes somewhat pointless (in this context)
您可以使用某种方式将要绘制的内容从Wilk(控制器)传达到Plansza(视图).这通常是通过使用某种模型来实现的，该模型允许您的控制器更改其状态，并通过视图呈现该状态.
What you could use is some way to communicate what you want to paint from your Wilk (controller) to Plansza (view). This is typically achieved via the use of some kind of model, which allows your controller to change it's state and your view to render that state.
例如...
这是模型-的基本演示. Control-View 实现.
模型驱动视图，而控制器驱动模型.这样，只要满足模型的约定，各个要素就可以相互独立
The model drives the view and the controller drives the model. In this way, so long as the contract of the model is meet, the various elements are independent of each other
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class PaintModel {
public static void main(String[] args) {
new PaintModel();
}
public PaintModel() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
MutableModel model = new DefaultModel();
Controller controller = new Controller(model);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new View(model));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
controller.start();
}
});
}
public interface Model {
public Rectangle getBounds();
public Dimension getSize();
public void addChangeListener(ChangeListener listener);
public void removeChangeListener(ChangeListener listener);
}
public interface MutableModel extends Model {
public void update();
}
public class DefaultModel implements MutableModel {
private final Dimension size = new Dimension(200, 200);
private final Rectangle bounds = new Rectangle(95, 95, 10, 10);
private int xDelta = ((int) (Math.random() * 5)) + 1;
private int yDelta = ((int) (Math.random() * 5)) + 1;
private List<ChangeListener> changeListeners;
public DefaultModel() {
changeListeners = new ArrayList<>(25);
}
@Override
public void addChangeListener(ChangeListener listener) {
changeListeners.add(listener);
}
@Override
public void removeChangeListener(ChangeListener listener) {
changeListeners.remove(listener);
}
protected void fireStateChanged() {
if (changeListeners.size() > 0) {
ChangeEvent evt = new ChangeEvent(this);
Iterator<ChangeListener> it = changeListeners.iterator();
while (it.hasNext()) {
ChangeListener listener = it.next();
listener.stateChanged(evt);
}
}
}
@Override
public Dimension getSize() {
return size;
}
@Override
public Rectangle getBounds() {
return bounds;
}
@Override
public void update() {
bounds.x += xDelta;
bounds.y += yDelta;
if (bounds.x < 0) {
bounds.x = 0;
xDelta *= -1;
} else if (bounds.x + bounds.width > size.width) {
bounds.x = size.width - bounds.width;
xDelta *= -1;
}
if (bounds.y < 0) {
bounds.y = 0;
yDelta *= -1;
} else if (bounds.y + bounds.height > size.height) {
bounds.y = size.height - bounds.height;
yDelta *= -1;
}
fireStateChanged();
}
}
public class Controller extends Thread {
private MutableModel model;
public Controller(MutableModel model) {
this.model = model;
setDaemon(true);
}
@Override
public void run() {
while (true) {
try {
Thread.sleep(40);
} catch (InterruptedException ex) {
}
model.update();
}
}
}
public class View extends JComponent implements ChangeListener {
private Model model;
public View(Model model) {
this.model = model;
this.model.addChangeListener(this);
setBackground(Color.WHITE);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(model.getSize());
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(getBackground());
g2d.fillRect(0, 0, getWidth(), getHeight());
Rectangle bounds = model.getBounds();
g2d.setColor(Color.BLUE);
g2d.drawOval(bounds.x, bounds.y, bounds.width, bounds.height);
g2d.dispose();
}
@Override
public void stateChanged(ChangeEvent e) {
repaint();
}
}
}
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