我如何从另一个类访问某些变量?例如,我有2个文件:从类到类的访问变量
Main.java
package keyboardgame;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class Main extends Applet implements KeyListener
{
private static final long serialVersionUID = 1L;
private static boolean keyboardRightPressed = false;
private static boolean keyboardLeftPressed = false;
private static boolean keyboardUpPressed = false;
private static boolean keyboardDownPressed = false;
int ballX = 20;
int ballY = 20;
int ballSpeed = 10;
public void init()
{
addKeyListener(this);
}
public void keyPressed(KeyEvent e)
{
int keyCode = e.getKeyCode();
if(keyCode == KeyEvent.VK_RIGHT)
{
keyboardRightPressed = true;
ballX = ballX + ballSpeed;
repaint();
}
if(keyCode == KeyEvent.VK_LEFT)
{
keyboardLeftPressed = true;
ballX = ballX - ballSpeed;
repaint();
}
if(keyCode == KeyEvent.VK_UP)
{
keyboardUpPressed = true;
ballY = ballY - ballSpeed;
repaint();
}
if(keyCode == KeyEvent.VK_DOWN)
{
keyboardDownPressed = true;
ballY = ballY + ballSpeed;
repaint();
}
}
public void keyReleased(KeyEvent e)
{
int keyCode = e.getKeyCode();
if(keyCode == KeyEvent.VK_RIGHT)
{
keyboardRightPressed = false;
repaint();
}
if(keyCode == KeyEvent.VK_LEFT)
{
keyboardLeftPressed = false;
repaint();
}
if(keyCode == KeyEvent.VK_UP)
{
keyboardUpPressed = false;
repaint();
}
if(keyCode == KeyEvent.VK_DOWN)
{
keyboardDownPressed = false;
repaint();
}
}
public void keyTyped(KeyEvent e) {
}
public void paint(Graphics g)
{
g.fillOval(ballX,ballY,20,20);
g.drawString("Right :"+keyboardRightPressed,0,10);
g.drawString("Left :"+keyboardLeftPressed,0,20);
g.drawString("Up :"+keyboardUpPressed,0,30);
g.drawString("Down :"+keyboardDownPressed,0,40);
}
}
KeyThread.java
package keyboardgame;
public class KeyThread implements Runnable
{
public KeyThread(String s,int speed)
{
name = s;
time = speed;
}
public void run()
{
try
{
if(keyboardRightPressed == true)
{
ballX = ballX + 10;
ballY = ballY + 10;
}
}
catch(Exception e)
{
}
}
}
什么我想的是,从KeyThread.java是能够修改/增加/访问值从Main.java特别是
int ballX = 20;
int ballY = 20;
,所以我可以打电话给我的线程Main.java像
Thread t5 = new Thread(new KeyThread("Moving Right", ballX = ballX + 1, 20));
t5.start();
我怎样才能做到这一点? 为什么它很难做到这一点?
既然您是JAVA的新手,正如您在某些评论中所说的那样,您为什么不尝试JApplet,而不是从javax.swing包中取得Applet。这与来自java.awt包的Applet相比要好得多。问候 – 2012-01-17 12:39:32