java - JPanel 在 For 循环完成之前不会更新或重新绘制

Question

我知道这可能是一个非常简单的问题，但由于我只使用了 JPanel 和 JFrame 一个周末，所以请不要对我太挑剔。我的问题是我有这个代码:

package Game_Elements;
import java.awt.Color;
import java.awt.Desktop.Action;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.RenderingHints.Key;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.AbstractAction;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Game implements KeyListener
{
private JFrame frame = null;
private JPanel panel = null;
int y = 0;
int x = 0;
public boolean W_TRUE;
public boolean S_TRUE;
public boolean A_TRUE;
public boolean D_TRUE;
public void keyPressed(KeyEvent e)
{

    if(e.getKeyCode()== KeyEvent.VK_W){
            y-= 15;
            panel.setLocation(x, y);
            W_TRUE = true;

    }
    if(e.getKeyCode()== KeyEvent.VK_S){
            y+= 15;
            panel.setLocation(x, y);
            S_TRUE = true;
    }
    if(e.getKeyCode()== KeyEvent.VK_A){
            x-= 15;
            panel.setLocation(x, y);
            A_TRUE = true;
    }
    if(e.getKeyCode()== KeyEvent.VK_D){
            x+= 15;
            panel.setLocation(x, y);
            D_TRUE = true;
    }
    if(D_TRUE == true  && S_TRUE == true ){
        y+= 15;
        x+= 15;
        panel.setLocation(x, y);
    }
    if(A_TRUE == true  && W_TRUE == true ){
        y-= 15;
        x-= 15;
        panel.setLocation(x, y);
    }
    if(A_TRUE == true  && S_TRUE == true ){
        y+= 15;
        x-= 15;
        panel.setLocation(x, y);
    }
    if(D_TRUE == true && W_TRUE == true ){
        y-= 15;
        x+= 15;
        panel.setLocation(x, y);
    }
}
public void keyReleased(KeyEvent e)
{
    if(e.getKeyCode()== KeyEvent.VK_W){
        W_TRUE = false;
}
if(e.getKeyCode()== KeyEvent.VK_S){
        S_TRUE = false;
}
if(e.getKeyCode()== KeyEvent.VK_A){
        A_TRUE = false;
}
if(e.getKeyCode()== KeyEvent.VK_D){
        D_TRUE = false;
}
if(e.getKeyCode()== KeyEvent.VK_SPACE){
    System.out.println("Running JUMP");
    for(int j = y - 200; j < y; y-= 15){
        try {
            Thread.sleep(10);
        } catch (InterruptedException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        panel.setLocation(x, y);
        panel.revalidate();
    }   
    System.out.println("Complete");

}
}

public void keyTyped(KeyEvent e) {

}

public void frameStart()
{

    frame = new JFrame();
    frame.setVisible(true);
    frame.setTitle("Desperation");
    frame.getContentPane().setLayout(new BoxLayout(frame.getContentPane(), BoxLayout.Y_AXIS)); // otherwise nice exceptions java.awt.AWTError:
    frame.setPreferredSize(new Dimension(1920, 1050));
    frame.setSize(new Dimension(1920, 1050));
    frame.setResizable(false);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    System.out.println("Frame Created");

    panel = new JPanel();
    panel.setBackground(Color.BLUE);
    panel.setMaximumSize(new Dimension(200, 200));
    panel.setLocation(1080, 500);
    panel.revalidate();
    frame.add(panel);
    System.out.println("Panel Created");

    frame.addKeyListener(this);
    System.out.println("Listener Created");
}

public static void main(String[] args){

    Game obj = new Game();

    obj.frameStart();
}

}

我的面板是一个基本的 200x200 蓝色立方体，在循环运行完成之前似乎不会改变位置，所以它更像是一个跳跃。我知道重绘功能只会尽快运行，因为这可能是问题所在，我想知道各位好心人是否有关于刷新它的替代方法的建议，这样它不一定看起来很顺利，但至少显示出一些进展。任何建议都将受到赞赏，因为我对 JPanel、JFrame 或真正的 JAnything 知之甚少。谢谢!

Answer 1

为了刷新

this.revalidate(); 

是“刷新”JComponent 的好方法