这是我提供问题的代码.
package ca.rhinoza.game;
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Dimension;
import javax.swing.JFrame;
public boolean running = false;
public class Game extends Canvas implements Runnable {
private static final long serialVersionUID = 1L;
public static final int WIDTH = 160;
public static final int HEIGHT = WIDTH / 12 * 9;
public static final int SCALE = 3;
public static final String NAME = "Game";
private JFrame frame;
public Game(){
setMinimumSize(new Dimension(WIDTH*SCALE,HEIGHT*SCALE));
setMaximumSize(new Dimension(WIDTH*SCALE,HEIGHT*SCALE));
setPreferredSize(new Dimension(WIDTH*SCALE,HEIGHT*SCALE));
frame = new JFrame(NAME);
frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(this,BorderLayout.CENTER);
frame.pack();
frame.setResizable(false);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public synchronized void start(){
new Thread(this).start();
}
public synchronized void stop(){
}
public void run() {
}
public static void main(String[] args){
new Game().start();
}
}
我不知道为什么会这样做.
编辑：
我根据您的要求编辑了更多代码.
解决方法
你在课堂外声明一个字段：
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Dimension;
import javax.swing.JFrame;
public boolean running = false; /// <=============== invalid location
public class Game extends Canvas implements Runnable { // <==== class starts here
private static final long serialVersionUID = 1L;
public static final int WIDTH = 160;
public static final int HEIGHT = WIDTH / 12 * 9;
public static final int SCALE = 3;
public static final String NAME = "Game";
...
它必须放在一个类中,如下所示：
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Dimension;
import javax.swing.JFrame;
public class Game extends Canvas implements Runnable { // <==== class starts here
public boolean running = false; /// <=============== valid location
private static final long serialVersionUID = 1L;
public static final int WIDTH = 160;
public static final int HEIGHT = WIDTH / 12 * 9;
public static final int SCALE = 3;
public static final String NAME = "Game";
...
