Volg de onderstaande video om te zien hoe je onze site als web-app op je startscherm installeert.
Opmerking: Deze functie is mogelijk niet beschikbaar in sommige browsers.
Als je van plan bent om deftig te leren werken met java is het toch belangrijk om eerst wat met de basisdingen te experimenteren want zo leer je het meest.import java.awt.*;
class Ball extends Thread
{
private boolean ismoving;
private Graphics g;
private int x =7;
private int y =0;
private int xChange =7;
private int yChange =2;
private int diameter = 10;
private int rectLeftX = 0, rectRightX = 500;
private int rectTopY = 0, rectBottomY = 500;
public Ball(Graphics gr)
{
g=gr;
ismoving = true;
}
public void end()
{
ismoving = false;
}
public void run()
{
g.drawRect(rectLeftX, rectTopY,
rectRightX - rectLeftX, rectBottomY - rectTopY);
while (ismoving)
{
g.setColor(Color.red);
g.fillOval(x,y,diameter,diameter);
if (x + xChange <= rectLeftX)
xChange = -xChange;
if (x + xChange >= rectRightX)
xChange = -xChange;
if (y + yChange <= rectTopY)
yChange = -yChange;
if (y + yChange >= rectBottomY)
yChange = -yChange;
x = x + xChange;
y = y + yChange;
try
{
Thread.sleep(50);
}
catch (InterruptedException e)
{
System.err.println("sleep exception");
}
}
}
}
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CkBreakout extends JFrame
{
public void main(String args[])
{
CkBreakout application = new CkBreakout();
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
startGame();
}
public CkBreakout()
{
super("CkBreakout");
setSize(860,660);
setVisible(true);
}
public void startGame()
{
Graphics g;
;
Ball ball= new Ball(g);
ball.start();
}
}
CkBreakout.java:24: variable g might not have been initialized
Ball ball= new Ball(g);
^
1 error
Bewerking afgesloten het fout-code 1
schop aars zei:iemand die mij hierbij kan helpen??

import java.awt.*;
class Ball extends Thread
{
private boolean ismoving;
private Graphics g;
private int x =57;
private int y =50;
private int xChange =7;
private int yChange =2;
private int diameter = 10;
private int rectLeftX = 50, rectRightX = 500;
private int rectTopY = 50, rectBottomY = 500;
public Ball(Graphics gr)
{
g=gr;
ismoving = true;
}
public void end()
{
ismoving = false;
}
public void run()
{
g.drawRect(rectLeftX, rectTopY,
rectRightX - rectLeftX, rectBottomY - rectTopY);
while (ismoving)
{
g.setColor(Color.red);
g.fillOval(x,y,diameter,diameter);
if (x + xChange <= rectLeftX)
xChange = -xChange;
if (x + xChange >= rectRightX)
xChange = -xChange;
if (y + yChange <= rectTopY)
yChange = -yChange;
if (y + yChange >= rectBottomY)
yChange = -yChange;
x = x + xChange;
y = y + yChange;
try
{
Thread.sleep(50);
}
catch (InterruptedException e)
{
System.err.println("sleep exception");
}
}
}
}
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CkBreakout extends JFrame
{
private JLabel score;
public static void main(String args[])
{
CkBreakout application = new CkBreakout();
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public CkBreakout()
{
super("CkBreakout");
JMenu ck = new JMenu("CkBreakout");
ck.setMnemonic('k');
JMenuItem play = new JMenuItem("Play");
play.setMnemonic('P');
play.addActionListener(
new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
startGame();
}
}
);
ck.add(play);
JMenuBar bar = new JMenuBar();
setJMenuBar(bar);
bar.add(ck);
setSize(1000,700);
setVisible(true);
}
public void startGame()
{
Graphics g= getGraphics();
Ball ball= new Ball(g);
ball.start();
}
}
.Acku. zei:public void run()
{
g.fillRect(rectLeftX, rectTopY,rectRightX - rectLeftX, rectBottomY - rectTopY);
g.drawRect(rectLeftX, rectTopY,rectRightX - rectLeftX, rectBottomY - rectTopY);
Zou de truc wel eens kunnen doen, je doet maw gewoon eerst een clearscreen.
