我正在使用递归来创建动画，显示河内塔的过程。
这是我的完整代码，我的问题是当我使用main调用move()函数时，一切正常，但是当我尝试使用按钮时，它不起作用。控制台输出指示move()被调用，但窗口没有刷新。真的被困在这里，非常感谢。
public class TowerOfHanoi<T>{
//empty constructor, just for calling initializing methods
public TowerOfHanoi(){
}
private int numberOfLayers;
private Object[] towerA;
private Object[] towerB;
private Object[] towerC;
public int towerHeightOf(Object[] theTower){
int result =0;
for(Object current: theTower){
if(current != null){
result++;
}
}
return result;
}
// initialize the arrays that holds the integer that represent the plate in tower
public void setLayerNbr(int layerNbr){
this.numberOfLayers = layerNbr;
this.moveCount = 0;
towerA = new Object[numberOfLayers];
towerB = new Object[numberOfLayers];
towerC = new Object[numberOfLayers];
//initialize the tower A
for(int i=0; i< numberOfLayers; i++){
towerA[i] = new Integer(layerNbr--);
}
}
//these are the plate shifting method
//return the top most element of the tower
//warning, you are not only get the top plate, but remove it from the original racket as well
//specifications is the hardest stuff
@SuppressWarnings("unchecked")
public T getTopPlate(Object[] tower){
Object lastElement = null;
if(tower[tower.length-1] != null){
lastElement = tower[tower.length-1];
}
for(int i=tower.length-1; i>-1; i--){
if(tower[i] != null){
lastElement = tower[i];
tower[i] = null;
break;
}
}
return (T) lastElement;
}
// add a plate to a tower
public void addToTop(T currentPlate, Object[] targetTower){
for(int i=0; i< numberOfLayers; i++){
if(targetTower[i] == null){
targetTower[i] = currentPlate;
return;
}
}
}
// move the top plate from one to another
public void movePlate(Object[] originalTower, Object[] targetTower){
addToTop(getTopPlate(originalTower), targetTower);
}
public Object[] getTowerByName(char name){
Object[] result = null;
switch(name){
case 'A':
result = towerA;
break;
case 'B':
result = towerB;
break;
case 'C':
result = towerC;
break;
default:
break;
}
return result;
}
public void showTower(char name){
Object[] currentTower = getTowerByName(name);
for(int i=currentTower.length-1; i>-1; i--){
if(currentTower[i] != null){
System.out.println(currentTower[i].toString());
}else{
return;
}
}
}
/**
* in most scenarios, nested components plus layout manager can achieve what you want
*/
private int moveCount;
///////
///////
///////
///////
private JFrame windowFrame; // top level container
private JPanel promptPanel; // contains the following two panels
private JLabel messageLabel;
private JLabel moveCountLabel;
private JPanel animationPanel;
private JPanel bottomeStaticPanel;// contains the following two panels
private JPanel buttonPanel; // contains the following
private JButton startBtn;
private JButton pauseBtn;
private JButton quitBtn;
private JPanel racketPanel; // contains the following 3 panels, using grid panel
private JLabel aLabel = new JLabel("A");
private JLabel bLabel = new JLabel("B");
private JLabel cLabel = new JLabel("C");
//display the static background of the window
public void display(){
windowFrame = new JFrame("Tower of Hanoi");
windowFrame.setSize(1200, 700);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
windowFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
windowFrame.setBackground(Color.white);
Container frameContainer = windowFrame.getContentPane();
//set up the prompt panel
promptPanel = new JPanel(new BorderLayout());
messageLabel = new JLabel("Click \"Start\" to see the move! ");
moveCountLabel = new JLabel("Moves Count: "+ moveCount+" ");
Font messageFont = new Font(Font.SANS_SERIF, Font.BOLD, 20);
Font moveCountFont = new Font(Font.DIALOG, Font.BOLD, 15);
messageLabel.setFont(messageFont);
moveCountLabel.setFont(moveCountFont);
messageLabel.setHorizontalAlignment(SwingConstants.CENTER);
moveCountLabel.setHorizontalAlignment(SwingConstants.LEFT);
promptPanel.add(messageLabel,BorderLayout.CENTER);
promptPanel.add(moveCountLabel,BorderLayout.EAST);
//set up the animation panel
// todo: back ground color to be changed
animationPanel = new JPanel();
animationPanel.setPreferredSize(new Dimension(1200, 700));
animationPanel.setBackground(Color.lightGray);
animationPanel.setLayout(new BorderLayout());
//set up the racket panel
aLabel = new JLabel("Tower A");
bLabel = new JLabel("Tower B");
cLabel = new JLabel("Tower C");
Font racketFont = new Font(Font.SERIF, Font.BOLD, 17);
aLabel.setFont(racketFont);
bLabel.setFont(racketFont);
cLabel.setFont(racketFont);
aLabel.setHorizontalAlignment(SwingConstants.CENTER);
bLabel.setHorizontalAlignment(SwingConstants.CENTER);
cLabel.setHorizontalAlignment(SwingConstants.CENTER);
racketPanel = new JPanel(new GridLayout(1, 3));
racketPanel.add(aLabel);
racketPanel.add(bLabel);
racketPanel.add(cLabel);
racketPanel.setBackground(Color.lightGray);
//set up the button panel
buttonPanel = new JPanel();
startBtn = new JButton("Start");
pauseBtn = new JButton("Pause");
quitBtn = new JButton("Quit");
startBtn.setEnabled(true);
pauseBtn.setEnabled(false);
quitBtn.setEnabled(true);
buttonPanel.add(startBtn);
buttonPanel.add(pauseBtn);
buttonPanel.add(quitBtn);
//set up the bottom panel
bottomeStaticPanel = new JPanel(new BorderLayout());
bottomeStaticPanel.add(racketPanel, BorderLayout.NORTH);
bottomeStaticPanel.add(buttonPanel, BorderLayout.SOUTH);
//set up the whole window frame
frameContainer.add(promptPanel,BorderLayout.NORTH);
frameContainer.add(animationPanel, BorderLayout.CENTER);
frameContainer.add(bottomeStaticPanel, BorderLayout.SOUTH);
//position the window frame on screen and display it
windowFrame.setLocation(dim.width/2-windowFrame.getSize().width/2, dim.height/2-windowFrame.getSize().height/2);
windowFrame.setVisible(true);
///*******////
///*******////
///*******////
///*******////
//NOTE: since the constructor of the paintable panel needs animation panel's size, we need to make the JFrame render first
PaintablePanel canvas = new PaintablePanel();// the panel actually do the animation
animationPanel.add(canvas, BorderLayout.CENTER); //make the canvas take up the entire animation panel
//Why make this nested structure, this way we can get size of the container.
//this is vital, you must repaint after adding something to the container?
//Other wise the change will not show up
windowFrame.revalidate();
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void setUpActionListeners(){
startBtn.addActionListener(new startBtnListener());
pauseBtn.addActionListener(new pauseBtnListener());
quitBtn.addActionListener(new quitBtnListener());
}
@SuppressWarnings("serial")
class PaintablePanel extends JPanel{
//dimension constant
private final int HORIZONTAL_UNIT = animationPanel.getWidth()/1200; // 10 pixel per unit
private final int PLATE_THICKNESS = animationPanel.getHeight()/(numberOfLayers+1);
private final int BORDER_WIDTH = 2;
private final int VERTICAL_BAR_STARTING_X = HORIZONTAL_UNIT*200-5;
private final int BAR_HEIGHT =PLATE_THICKNESS*(numberOfLayers+1) ;
private final int VERTICAL_BAR_STARTING_Y = animationPanel.getHeight()-BAR_HEIGHT;
private final int PLATE_WIDTH_UNIT = 300*HORIZONTAL_UNIT/numberOfLayers;
//color constant
private final Color PLATE_COLOR = Color.CYAN;
private final Color PLATE_BORDER_COLOR = Color.DARK_GRAY;
private final Color VERTICAL_BAR_COLOR = Color.black;
private final Color CHARACTER_COLOR = Color.blue;
@Override
public void paint(Graphics g){
//todo : paint three towers according to its current status
//paint the vertical bar;
g.setColor(VERTICAL_BAR_COLOR);
for(int i=0; i<3;i++){
g.fillRect(VERTICAL_BAR_STARTING_X+i*400*HORIZONTAL_UNIT
,VERTICAL_BAR_STARTING_Y
,10
,BAR_HEIGHT);
}
//debug
int AHeight = towerHeightOf(towerA);
int BHeight = towerHeightOf(towerB);
int CHeight = towerHeightOf(towerC);
for(int i=0; i<AHeight; i++){
Integer currentPlate = (Integer)towerA[i];
//NOTE: cast to double then cast back to int, make sure there is always something to display
int outterX= (int) (200*HORIZONTAL_UNIT - ((double)currentPlate.intValue())/2*PLATE_WIDTH_UNIT);
int outterY= animationPanel.getHeight() - PLATE_THICKNESS*(i+1); //the shifting amount of outterY relates to the layers accumulated
int outterWidth = currentPlate.intValue()*PLATE_WIDTH_UNIT;
int outterHeight = PLATE_THICKNESS;
int innerX = outterX+BORDER_WIDTH;
int innerY = outterY+BORDER_WIDTH;
int innerWidth = outterWidth - 2*BORDER_WIDTH;
int innerHeight = outterHeight - 2*BORDER_WIDTH;
int centerX = 200*HORIZONTAL_UNIT;
int centerY = outterY+PLATE_THICKNESS/2;
Font characterFont = new Font(Font.SERIF, Font.BOLD, PLATE_THICKNESS/4);
g.setColor(PLATE_BORDER_COLOR);
g.fillRect(outterX, outterY, outterWidth, outterHeight);
g.setColor(PLATE_COLOR);
g.fillRect(innerX, innerY, innerWidth, innerHeight);
g.setColor(CHARACTER_COLOR);
g.setFont(characterFont);
g.drawString(currentPlate.toString(), centerX-characterFont.getSize()/3, centerY+characterFont.getSize()/4);
}
for(int i=0; i<BHeight; i++){
Integer currentPlate = (Integer)towerB[i];
//NOTE: cast to double then cast back to int, make sure there is always something to display
int outterX= (int) (600*HORIZONTAL_UNIT - ((double)currentPlate.intValue())/2*PLATE_WIDTH_UNIT);
int outterY= animationPanel.getHeight() - PLATE_THICKNESS*(i+1); //the shifting amount of outterY relates to the layers accumulated
int outterWidth = currentPlate.intValue()*PLATE_WIDTH_UNIT;
int outterHeight = PLATE_THICKNESS;
int innerX = outterX+BORDER_WIDTH;
int innerY = outterY+BORDER_WIDTH;
int innerWidth = outterWidth - 2*BORDER_WIDTH;
int innerHeight = outterHeight - 2*BORDER_WIDTH;
g.setColor(PLATE_BORDER_COLOR);
g.fillRect(outterX, outterY, outterWidth, outterHeight);
g.setColor(PLATE_COLOR);
g.fillRect(innerX, innerY, innerWidth, innerHeight);
int centerX = 600*HORIZONTAL_UNIT;
int centerY = outterY+PLATE_THICKNESS/2;
Font characterFont = new Font(Font.SERIF, Font.BOLD, PLATE_THICKNESS/4);
g.setColor(CHARACTER_COLOR);
g.setFont(characterFont);
g.drawString(currentPlate.toString(), centerX-characterFont.getSize()/3, centerY+characterFont.getSize()/4);
}
for(int i=0; i<CHeight; i++){
Integer currentPlate = (Integer)towerC[i];
//NOTE: cast to double then cast back to int, make sure there is always something to display
int outterX= (int) (1000*HORIZONTAL_UNIT - ((double)currentPlate.intValue())/2*PLATE_WIDTH_UNIT);
int outterY= animationPanel.getHeight() - PLATE_THICKNESS*(i+1); //the shifting amount of outterY relates to the layers accumulated
int outterWidth = currentPlate.intValue()*PLATE_WIDTH_UNIT;
int outterHeight = PLATE_THICKNESS;
int innerX = outterX+BORDER_WIDTH;
int innerY = outterY+BORDER_WIDTH;
int innerWidth = outterWidth - 2*BORDER_WIDTH;
int innerHeight = outterHeight - 2*BORDER_WIDTH;
g.setColor(PLATE_BORDER_COLOR);
g.fillRect(outterX, outterY, outterWidth, outterHeight);
g.setColor(PLATE_COLOR);
g.fillRect(innerX, innerY, innerWidth, innerHeight);
int centerX = 1000*HORIZONTAL_UNIT;
int centerY = outterY+PLATE_THICKNESS/2;
Font characterFont = new Font(Font.SERIF, Font.BOLD, PLATE_THICKNESS/4);
g.setColor(CHARACTER_COLOR);
g.setFont(characterFont);
g.drawString(currentPlate.toString(), centerX-characterFont.getSize()/3, centerY+characterFont.getSize()/4);
}
}
}
/**
* This method prints out the steps to achieve Hanoi Tower
*
* @param numberOfPlates how many plates are in the number
* @param homeStack
* @param aimStack
* @param mediaStack
*/
public void move(int numberOfPlates, char homeStack
, char targetStack
, char mediaStack ){
if(numberOfPlates == 1){
//debug
//debug
windowFrame.revalidate();
windowFrame.repaint();
System.out.println("repaint() get called");
System.out.println("Move "+ numberOfPlates+" from Stack \'"+ homeStack+"\' to "+"Stack \'"+targetStack+"\'");
//Truly needed
messageLabel.setText("Move "+ numberOfPlates+" from Stack \'"+ homeStack+"\' to "+"Stack \'"+targetStack+"\'");
movePlate(getTowerByName(homeStack), getTowerByName(targetStack));
moveCount++;
moveCountLabel.setText("Moves Count: "+ moveCount+" ");
//delay the move step for one second
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return;
}
move(numberOfPlates-1, homeStack, mediaStack, targetStack);
//debug
windowFrame.revalidate();
windowFrame.repaint();
System.out.println("Move "+ numberOfPlates+" from Stack \'"+ homeStack+"\' to "+"Stack \'"+targetStack+"\'");
//debug
messageLabel.setText("Move "+ numberOfPlates+" from Stack \'"+ homeStack+"\' to "+"Stack \'"+targetStack+"\'");
movePlate(getTowerByName(homeStack), getTowerByName(targetStack));
moveCount++;
moveCountLabel.setText("Moves Count: "+ moveCount+" ");
//delay the move step
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
move(numberOfPlates-1, mediaStack, targetStack, homeStack);
}
class startBtnListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
startBtn.setEnabled(false);
pauseBtn.setEnabled(true);
quitBtn.setEnabled(true);
windowFrame.revalidate();
windowFrame.repaint();
System.out.println("move started");
move(numberOfLayers, 'A', 'C', 'B');
System.out.println("move finished");
}
}
// to be fixed
class pauseBtnListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
String status = "";
if(pauseBtn.getText() == "Pause"){
pauseBtn.setText("Resume");
status = "Resume";
}else{
pauseBtn.setText("Pause");
}
//hang up the current thread
while(status != "Resume"){
try {
Thread.sleep(250);
} catch (InterruptedException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
}
}
class quitBtnListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
userChoseQuit();
}
}
////////////////
////////////////
////////////////
//check if the input string represent a valid integer
public boolean isAValidInteger(String rawInput) {
try {
Integer.parseInt(rawInput);// throw exception if rawInput is not
// integer
return true;
} catch (NumberFormatException e) {
JOptionPane.showMessageDialog(null, "Input must be an integer",
"Invalid input", JOptionPane.INFORMATION_MESSAGE);
return false;
}
}
// This method show a message if the user click cancel during the execution
// of the program
// and terminate the program
public void userChoseQuit() {
JOptionPane.showMessageDialog(null,
"Program terminated by user before finish execution.",
"Program exit successfully, good bye! ", JOptionPane.INFORMATION_MESSAGE);
System.exit(0);
}
//recursively validating the input
public int getInput(){
String userInputLayersNbr = JOptionPane.showInputDialog(null,
"Please Enter the Number Of Layers of Hanoi Tower:",
"Wecome To Tower Of Hanoi Animation", JOptionPane.QUESTION_MESSAGE);
if(userInputLayersNbr == null){
this.userChoseQuit();
return -1;
}else{
if(this.isAValidInteger(userInputLayersNbr)){
int layerNbr = Integer.parseInt(userInputLayersNbr);
if(layerNbr >= 1){
return layerNbr;
}else{
JOptionPane.showMessageDialog(null,
"Number of layers must be an integer greater than 0",
"Try Again Please", JOptionPane.WARNING_MESSAGE);
return this.getInput();
}
}
return this.getInput();
}
}
/////////////////
/////////////////
/////////////////
public static void main(String[] args){
TowerOfHanoi<Integer> theTower = new TowerOfHanoi<>();
int layerNbr =theTower.getInput();
theTower.setLayerNbr(layerNbr);
theTower.display();
theTower.setUpActionListeners();
//let us use the button to call move now
//theTower.move(layerNbr, 'A', 'C', 'B');
return;
}
}
答案 0 :(得分：2)
当我使用main调用move（）函数时，一切正常
从main（）方法调用的代码在一个单独的Thread上运行（由于所有GUI代码都应该在Event Dispatch Thread（EDT）上创建，所以这是错误的。
当我尝试使用按钮时，它不起作用
在EDT上调用在侦听器中执行的代码，EDT是负责重新绘制GUI的线程。由于你有一个Thread.sleep（），这将导致EDT进入睡眠状态，这意味着GUI无法自行重绘。
阅读Concurrency上Swing教程中的部分，了解有关此概念的更多信息。
解决方案是为长时间运行的任务使用单独的Thread，然后当您使Thread休眠时，它不会影响GUI。
或许您可以使用Swing Timer来安排动画，因此您不需要使用Thread.sleep。无论如何，代码需要重组。阅读教程。本教程还有一个关于计时器的部分。
此外，您不应该重写paint（）方法。自定义绘制是通过覆盖面板的paintComponent（）方法完成的，不要忘记调用super.paintComponent（）来清除背景。