我正在尝试对从站到站的火车进行java模拟。我的主要代码在工作，但GUI遇到问题。我具有带“开始”和“停止”按钮的基本布局，但是一旦选择了“开始”按钮，主循环即会运行以进行仿真，并且GUI不会响应。我一直很难找到解决方法。帮助将不胜感激！
这是主要的模拟课程：
/ ** *这是运行主循环的主要模拟类。 *它使用两个类的实例：火车和车站。 * @作者Ollie Jones * * / 公共课程SimEngine {
/**
* Station object array and train object initialised.
* The line has 16 station so an array of 16 is needed.
*/
Station[] station = new Station[16];
Train train = new Train();
int forwardTimeArray[];
int backwardTimeArray[];
/**
* Constructor for objects of class SimEngine
*/
public SimEngine()
{
/**
* Here that values are initialised.
*/
train = new Train();
forwardTimeArray = new int[]{1,4,2,4,6,3,3,5,3,2,5,5,1,4,2};
backwardTimeArray = new int[]{3,2,4,5,2,2,4,3,4,2,5,2,1,4,5};
// A for loop is used to initialse the station number
for(int i=0; i<station.length; i++){
station[i] = new Station();
station[i].setStationNumber(i+1);
}
/**
* Each station name is initialised separately as
* they all have different names.
*/
station[0].setStationName("Name of 1st station");
station[1].setStationName("Name of 2nd station");
station[2].setStationName("Name of 3rd station");
station[3].setStationName("Name of 4th station");
station[4].setStationName("Name of 5ht station");
station[5].setStationName("Name of 6th station");
station[6].setStationName("Name of 7th station");
station[7].setStationName("Name of 8th station");
station[8].setStationName("Name of 9th station");
station[9].setStationName("Name of 10th station");
station[10].setStationName("Name of 11th station");
station[11].setStationName("Name of 12th station");
station[12].setStationName("Name of 13th station");
station[13].setStationName("Name of 14th station");
station[14].setStationName("Name of 15th station");
station[15].setStationName("Name of 16th station");
}
/**
* An example of a method - replace this comment with your own
*
* @param y a sample parameter for a method
* @return the sum of x and y
*/
/**
* This method stats the train simulation.
*
*/
public void start()
{
int x = 0;
System.out.println("Station Number:1"); //Print the first staion number.
while(x == 0){
int stationNumber = 0;
int time = 0;
Boolean forwards;
stationNumber = train.getStationNumber();
forwards = train.getDirection();
if (forwards == true){
time = forwardTimeArray[stationNumber-1];
sleep(time);
stationNumber = stationNumber + 1;
System.out.println("Station Nubmer:" + stationNumber);
train.setStationNumber(stationNumber);
}
else{
time = backwardTimeArray[stationNumber-2];
sleep(time);
stationNumber = stationNumber - 1;
System.out.println("Station Number:" + stationNumber);
train.setStationNumber(stationNumber);
}
if (stationNumber == 1){
forwards = true;
}
else if (stationNumber == 16){
forwards = false;
//train.setStationNumber(stationNumber-1);
}
train.setDirection(forwards);
}
}
public static void sleep(int time)
{
try{
time = time * 100;
Thread.sleep(time);
}
catch(Exception e) {}
}
public void stop()
{
System.exit(0);
}
}
这是开始模拟的sim类。
public class Sim
{
private GUI gui;
private SimEngine engine;
/**
* Constructor for objects of class sim
*
*/
public Sim()
{
engine = new SimEngine();
gui = new GUI(engine);
}
/**
* Opens window if it has been closed.
*/
public void show()
{
gui.setVisable(true);
}
}
这里是GUI，主要问题是（我认为）。
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
public class GUI extends JFrame
{
// instance variables - replace the example below with your own
private JFrame frame;
private JTextField display;
private final SimEngine sim;
private JLabel infoLabel;
/**
* Constructor for objects of class GUI
*/
public GUI(SimEngine engine)
{
// initialise instance variables
makeFrame();
frame.setVisible(true);
sim = engine;
}
/**
* Creates GUI frame!
*/
public void makeFrame()
{
frame = new JFrame("Train Simulation");
JPanel contentPane = (JPanel)frame.getContentPane();
contentPane.setLayout(new BorderLayout(8,8));
contentPane.setBorder(new EmptyBorder(10,10,10,10));
display = new JTextField();
contentPane.add(display, BorderLayout.NORTH);
JPanel buttonPanel = new JPanel(new GridLayout(1,2));
addButton(buttonPanel, "Start", () -> sim.start());
addButton(buttonPanel, "Stop", () -> sim.stop());
contentPane.add(buttonPanel, BorderLayout.CENTER);
frame.pack();
}
private void addButton(Container panel, String buttonText, ButtonAction
action)
{
JButton button = new JButton(buttonText);
button.addActionListener(e -> {action.act(); redisplay(); });
panel.add(button);
}
private interface ButtonAction
{
/**
* act on button press.
*/
void act();
}
private void redisplay()
{
}
/**
* Makes frame visable.
*/
public void setVisable(boolean visable){
frame.setVisible(visable);
}
}
答案 0 :(得分：1)
您正在事件分配线程上运行模拟。在进行计算时，它们将垄断处理UI事件的线程，因此它无法处理任何事情，并且UI冻结。
您似乎有这个用例（来自链接的教程）：
后台任务可以通过调用SwingWorker.publish提供中间结果，从而导致从事件分配线程中调用SwingWorker.process。
答案 1 :(得分：0)
如评论和this中所述，在The Event Dispatch Thread上运行长时间的进程会阻止它，因此它不会响应更改。
一种替代方法是使用SwingWorker，该方法以其doInBackground()方法进行后台处理，发布临时值（publish方法）并能够更新gui（process方法） 。
以下是基于您的代码的SwingWorker的基本实现。
可以将其复制粘贴到一个文件（GUI.java）中并运行。
注意代码中的注释：
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.GridLayout;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingWorker;
import javax.swing.border.EmptyBorder;
public class GUI extends JFrame
{
// instance variables - replace the example below with your own
private JFrame frame;
private JTextField display;
private final SimEngine sim;
private JLabel infoLabel;
/**
* Constructor for objects of class GUI
*/
public GUI(SimEngine engine)
{
// initialize instance variables
makeFrame();
frame.setVisible(true);
sim = engine;
}
/**
* Creates GUI frame!
*/
public void makeFrame()
{
frame = new JFrame("Train Simulation");
JPanel contentPane = (JPanel)frame.getContentPane();
contentPane.setLayout(new BorderLayout(8,8));
contentPane.setBorder(new EmptyBorder(10,10,10,10));
display = new JTextField();
contentPane.add(display, BorderLayout.NORTH);
JPanel buttonPanel = new JPanel(new GridLayout(1,2));
addButton(buttonPanel, "Start", () -> sim.start());
addButton(buttonPanel, "Stop", () -> sim.stop());
contentPane.add(buttonPanel, BorderLayout.CENTER);
frame.pack();
}
private void addButton(Container panel, String buttonText, ButtonAction action)
{
JButton button = new JButton(buttonText);
button.addActionListener(e -> {action.act(); redisplay(); });
panel.add(button);
}
void updateDisplay(String newValue){
display.setText(newValue);
}
private interface ButtonAction
{
/**
* act on button press.
*/
void act();
}
private void redisplay() { }
/**
* Makes frame visible.
*/
public void setVisable(boolean visable){
frame.setVisible(visable);
}
public static void main(String[] args) {
Sim sim = new Sim();
sim.show();
}
}
//implements Listener so it can listen to SimEngine value changes
class Sim implements Listener
{
private final GUI gui;
private final SimEngine engine;
public Sim()
{
engine = new SimEngine(this);
gui = new GUI(engine);
}
/**
* make gui visible
*/
public void show()
{
gui.setVisable(true);
}
@Override
public void valueChanged(String newValue){
gui.updateDisplay(newValue);
}
}
class SimEngine {
/**
* Station object array and train object initialized.
* The line has 16 station so an array of 16 is needed.
*/
private final Station[] station = new Station[16];
private Train train = new Train();
private final int forwardTimeArray[], backwardTimeArray[];
private final Listener listener;
//accept a listener
public SimEngine(Listener listener)
{
this.listener = listener;
train = new Train();
forwardTimeArray = new int[] {1,4,2,4,6,3,3,5,3,2,5,5,1,4,2,3}; //needs 16 values, had only 16
backwardTimeArray = new int[]{3,2,4,5,2,2,4,3,4,2,5,2,1,4,5,4};
// A for loop is used to initialize the station number and name
for(int i=0; i<station.length; i++){
station[i] = new Station();
station[i].setStationNumber(i+1);
station[0].setStationName("Station #"+(i+1));
}
}
/**
* This method starts the train simulation.
*
*/
public void start()
{
//have all background processing done by a SwingWorker so GUI does not freeze
new SimulationWorker().execute();
}
public static void sleep(int time)
{
try{
Thread.sleep(time * 300);
}
catch(Exception e) {}
}
public void stop()
{
System.exit(0);
}
class SimulationWorker extends SwingWorker<Void,Integer>{
boolean stop = false; //use if you wish to stop
//do background processing
@Override
protected Void doInBackground() throws Exception {
while(! stop){
int stationNumber = 0;
int time = 0;
boolean forwards;
stationNumber = train.getStationNumber();
forwards = train.getDirection();
if (stationNumber == 1){
forwards = true;
train.setDirection(forwards);
}
else if (stationNumber == 15){
forwards = false;
train.setDirection(forwards);
}
if (forwards == true){
time = forwardTimeArray[stationNumber+1];//time = forwardTimeArray[stationNumber-1];
sleep(time);
stationNumber = stationNumber + 1;
//System.out.println("Station Number:" + stationNumber);
train.setStationNumber(stationNumber);
}
else{
time = backwardTimeArray[stationNumber-2];
sleep(time);
stationNumber = stationNumber - 1;
//System.out.println("Station Number:" + stationNumber);
train.setStationNumber(stationNumber);
}
publish(train.getStationNumber()); //publish result (station number)
}
return null;
}
//process published information
@Override
protected void process(List<Integer> stationsList) {
for(int stationNumber : stationsList){
listener.valueChanged("Train is at "+ stationNumber); //notify listener
}
}
}
}
class Train {
private int stationNumber = 0;
private boolean forwards = true ;
public int getStationNumber() {
return stationNumber;
}
public void setDirection(boolean forwards) {
this.forwards = forwards;
}
public void setStationNumber(int stationNumber) {
this.stationNumber = stationNumber;
}
public boolean getDirection() {
return forwards;
}
}
class Station {
private int stationNumber;
private String stationName;
public void setStationNumber(int stationNumber) {
this.stationNumber = stationNumber;
}
public void setStationName(String stationName) {
this.stationName = stationName;
}
}
//an interface use by Sim to listen to SimEngine changes
interface Listener {
void valueChanged(String newValue);
}