repaint() 不会在调用时重新绘制？

Question

我正在尝试制作三消游戏。我试图通过首先将需要删除的宝石标记为“黑色”，然后让重力来完成它的工作，从而为实际发生的事情创建一些视觉辅助。我正在努力做到这一点，在我将它们标记为“黑色”后，我打电话给repaint();，但它似乎不起作用。我还尝试按照另一个问题中的建议添加revalidate();，但这似乎也不能解决问题。这是困扰我的一段代码。

故障码：

public void deletePattern(Set<Gem> gemsToDelete){
    for(Gem gem : gemsToDelete)
        gem.setType(7);

    repaint(); //This doesn't seem to work

    doGravity();
    switchedBack = true;
    checkPattern();
}

我想在 doGravity() 之前和增强的 for 循环之后重新绘制电路板。难道是我在doGravity()方法中没有正确使用线程？

这是完整的代码：

Board.java

package Game;

import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.LinkedHashSet;
import java.util.Set;

public class Board extends JPanel{

    final int BOARDWIDTH = 8;
    final int BOARDHEIGHT = 8;

    private static final Color COLORS[] = { new Color(255, 0, 0), new Color(255, 128, 0), new Color(255, 255, 0), new Color(0, 255, 0), new Color(0, 255, 255), new Color(0, 0, 255), new Color(127, 0, 255), new Color(0, 0, 0), new Color(0, 0, 0), new Color(255, 255, 255)};

    boolean isAlive, isPattern, switchedBack;
    boolean isFirstSelected = false;
    Gem[][] gems;
    int fromX, fromY, toX, toY;

    public Board() {
        gems = new Gem[BOARDWIDTH][BOARDHEIGHT];
        addMouseListener(new MouseInputAdapter());
    }

    int cellWidth() { return (int) getSize().getWidth() / BOARDWIDTH; }

    int cellHeight() { return (int) getSize().getHeight() / BOARDHEIGHT; }

    public void start(){
        isPattern = switchedBack = false;
        isAlive = true;
        fillBoard();
        checkPattern();
        switchedBack = false;
    }

    public void paint(Graphics g) {
        super.paint(g);

        for (int x = 0; x < BOARDWIDTH; x++) {
            for (int y = 0; y < BOARDHEIGHT; y++)
                drawCell(g, x, y, gems[x][y]);
        }
    }

    public void fillBoard(){
        for (int x = 0; x < BOARDWIDTH; x++) {
            for (int y = 0; y < BOARDHEIGHT; y++)
                gems[x][y] = new Gem();
        }
    }

    public void drawCell(Graphics g, int x, int y, Gem gem) {
        x = x * cellWidth();
        y = y * cellHeight();

        g.setColor(COLORS[gem.getType()]);
        g.fillRect(x, y, x + cellWidth(), y + cellHeight());
    }

    class MouseInputAdapter extends MouseAdapter { @Override public void mouseClicked(MouseEvent e) { selectGems(e); } }

    public void selectGems(MouseEvent e){
        int x = e.getX() / cellWidth();
        int y = e.getY() / cellHeight();
        if(!isFirstSelected) {
            fromX = x;
            fromY = y;
            isFirstSelected = true;
        }else{
            toX = x;
            toY = y;
            if((Math.abs(fromX - toX) == 1 ^ Math.abs(fromY - toY) == 1) & (gems[fromX][fromY].getType() != gems[toX][toY].getType())) {
                switchGems();
                isFirstSelected = false;
            }
        }

    }

    public void switchGems(){
        int tempType = gems[fromX][fromY].getType();
        gems[fromX][fromY].setType(gems[toX][toY].getType());
        gems[toX][toY].setType(tempType);
        checkPattern();

        switchedBack = false;
        repaint();
    }

    public void checkPattern() {
        Set<Gem> gemsToDelete = new LinkedHashSet<>();

        isPattern = false;
        for (int x = 0; x < BOARDWIDTH; x++) {
            for (int y = 0; y < BOARDHEIGHT; y++) {
                if (x + 2 < BOARDWIDTH && (gems[x][y].getType() == gems[x + 1][y].getType()) && (gems[x + 1][y].getType() == gems[x + 2][y].getType())) { //Checks for 3 horizontal gems in a row
                    isPattern = true;
                    gemsToDelete.add(gems[x][y]);
                    gemsToDelete.add(gems[x + 1][y]);
                    gemsToDelete.add(gems[x + 2][y]);
                }
                if (y + 2 < BOARDHEIGHT && (gems[x][y].getType() == gems[x][y + 1].getType()) && (gems[x][y + 1].getType() == gems[x][y + 2].getType())) { //Check for 3 vertical gems in a row
                    isPattern = true;
                    gemsToDelete.add(gems[x][y]);
                    gemsToDelete.add(gems[x][y + 1]);
                    gemsToDelete.add(gems[x][y + 2]);
                }
            }
        }
        if(!gemsToDelete.isEmpty())
            deletePattern(gemsToDelete);

        if(!isPattern && !switchedBack){
            switchedBack = true;
            switchGems();
        }
    }

    public void deletePattern(Set<Gem> gemsToDelete){
        for(Gem gem : gemsToDelete)
            gem.setType(7);

        repaint(); //This doesn't seem to work

        doGravity();
        switchedBack = true;
        checkPattern();
    }

    public void doGravity(){
        try{
            Thread.sleep(1000);
        }catch(InterruptedException e){e.printStackTrace();}
        for (int y = 0; y < BOARDHEIGHT; y++) {
            for (int x = 0; x < BOARDWIDTH; x++) {
                if(gems[x][y].getType() == 7){
                    for (int i = y; i >= 0; i--) {
                        if(i == 0)
                            gems[x][i].setType(gems[x][i].genType());
                        else
                            gems[x][i].setType(gems[x][i-1].getType());
                    }
                }
            }
        }
    }
}

Gem.java

package Game;

public class Gem {

    private int type;

    public Gem(){
        this.type = genType();
    }

    public int genType(){ 
        return (int) (Math.random() * 7);
    }

    public void setType(int type){
        this.type = type;
    }

    public int getType(){
        return type;
    }
}

Game.java

package Game;

import javax.swing.*;

public class Game extends JFrame{

    public Game(){
        Board board = new Board();
        getContentPane().add(board);
        board.start();

        setTitle("Game");
        setSize(600, 600);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }

    public static void main(String[] args){
        Game game = new Game();
        game.setLocationRelativeTo(null);
        game.setVisible(true);
    }
}

Answer 1

您的代码是通过鼠标单击启动的。从 Swing 侦听器调用的代码在 Event Dispatch Thread (EDT) 上执行，它还负责绘制 GUI

doGravaity() 方法中的 Thread.sleep() 会导致 EDT 休眠，因此在整个循环代码完成之前，GUI 无法 repaint() 本身，此时它只会绘制动画的最终状态.

您需要使用Swing Timer 来安排动画，而不是休眠。所以基本上，在deletePattern() 方法中，您将启动 Timer 来执行重力动画。这将释放 EDT 以重新绘制自身，并且当 Timer 触发时，您将为组件设置动画，然后再次执行 repaint()。当组件完成移动时，您将停止计时器。

阅读 Concurrency 上的 Swing 教程部分，了解有关 EDT 的更多信息。

Answer 2

调用this.invalidate() 或this.postInvalidate()，然后强制重绘。