java - 我怎样才能让这个 JButton 重绘我的 Die Graphics？

Question

这是我要实现鼠标按钮的主类。我在使用 actionPerformed 区域中的代码时遇到问题，无法让骰子获得新值并在单击按钮时在同一位置重新绘制自身

---

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;


public class Game 
{
private static Die die;
public static void main(String[] agrs)
{
    JFrame frame = new JFrame();

    JPanel panel = new JPanel();
    panel.setLayout(new BorderLayout());

    JButton roll = new JButton("roll");
    class RollListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
          die.roll();
                            //This is where it is just replacing the first die
                      die2.roll2();
        }
    }
    RollListener listener = new RollListener();
    roll.addActionListener(listener);
    panel.add(roll,BorderLayout.NORTH);

    die = new Die(20,20, Roll.die1());
    panel.add(die, BorderLayout.CENTER);

                //This im pretty sure wont add correctly its just overlapping the first die
                //but from what iv seen if i use different layouts it draws different and sometimes not at all.
                die2 = new Die(75,20,Roll.die2());
                panel.add(die2, BorderLayout.CENTER);

    frame.add(panel);

    //When program closed it terminates program execution
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    //Makes frame visible
    frame.setVisible(true);
}
}

这是我创建模具的模具类

---

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.geom.Ellipse2D;

import javax.swing.JComponent;


public class Die extends JComponent
{
private static final long serialVersionUID = 1L;

//Variable for creating the die background
private Rectangle dieBorder;
//private int number = Roll.die1();
//Variable for creating the number of circles on die
private Ellipse2D numCircle;
private Ellipse2D numCircle2;
private Ellipse2D numCircle3;
private Ellipse2D numCircle4;
private Ellipse2D numCircle5;
private Ellipse2D numCircle6;
private Ellipse2D numCircle7;

      private int width = 50;
      private int height = 50;

/*
 * This constructs the DieComponent
 * with @param number. 
 */
public Die(int xPos, int yPos, int number1)
{
    number = number1;
    dieBorder = new Rectangle(xPos, yPos, width, height);

    numCircle = new Ellipse2D.Double(locationX(xPos, 2, 0), locationY(yPos, 2, 0), 8, 8);
    numCircle2 = new Ellipse2D.Double(locationX(xPos, 1, -7), locationY(yPos, 1, -7), 8, 8);
    numCircle3 = new Ellipse2D.Double(locationX(xPos, 1, -43), locationY(yPos, 1, -43), 8, 8);
    numCircle4 = new Ellipse2D.Double(locationX(xPos, 1, -7), locationY(yPos, 1, -43), 8, 8);
    numCircle5 = new Ellipse2D.Double(locationX(xPos, 1, -43), locationY(yPos, 1, -7), 8, 8);
    numCircle7 = new Ellipse2D.Double(locationX(xPos, 2, -18), locationY(yPos, 2, 0), 8, 8);
    numCircle6 = new Ellipse2D.Double(locationX(xPos, 2, 18), locationY(yPos, 2, 0), 8, 8);
}

/*
 * This will create the die graphics for 
 * the game. With @param g.
 */
public void paintComponent(Graphics g)
{
    Graphics2D g2 = (Graphics2D) g;
    super.paintComponent(g2);

    //Sets color of field
    g2.setColor(Color.RED);
    //Draws the die background
    g2.draw(dieBorder);
    //Fills in the background
    g2.fill(dieBorder);

    if(number == 1)
    {
    //Sets color to draw the circle with
    g2.setColor(Color.WHITE);
    //Draws the circle
    g2.draw(numCircle);
    //Fills in the circle
    g2.fill(numCircle);
    }

    if(number == 2)
    {
        g2.setColor(Color.WHITE);
        g2.draw(numCircle2);
        g2.draw(numCircle3);
        g2.fill(numCircle3);
        g2.fill(numCircle2);
    }

    if(number == 3)
    {
        g2.setColor(Color.WHITE);
        g2.draw(numCircle2);
        g2.draw(numCircle3);
        g2.draw(numCircle);
        g2.fill(numCircle3);
        g2.fill(numCircle2);
        g2.fill(numCircle);
    }

    if(number == 4)
    {
        g2.setColor(Color.WHITE);
        g2.draw(numCircle2);
        g2.draw(numCircle3);
        g2.draw(numCircle4);
        g2.draw(numCircle5);
        g2.fill(numCircle3);
        g2.fill(numCircle2);
        g2.fill(numCircle4);
        g2.fill(numCircle5);

    }

    if(number == 5)
    {
        g2.setColor(Color.WHITE);
        g2.draw(numCircle);
        g2.draw(numCircle2);
        g2.draw(numCircle3);
        g2.draw(numCircle4);
        g2.draw(numCircle5);
        g2.fill(numCircle3);
        g2.fill(numCircle2);
        g2.fill(numCircle4);
        g2.fill(numCircle);
        g2.fill(numCircle5);
    }

    if(number == 6)
    {
        g2.setColor(Color.WHITE);
        g2.draw(numCircle2);
        g2.draw(numCircle3);
        g2.draw(numCircle4);
        g2.draw(numCircle5);
        g2.draw(numCircle6);
        g2.draw(numCircle7);
        g2.fill(numCircle3);
        g2.fill(numCircle2);
        g2.fill(numCircle4);
        g2.fill(numCircle5);
        g2.fill(numCircle6);
        g2.fill(numCircle7);
    }
}

public static int locationX(int xPos, int spot, int move)
{
    int xPosition = (xPos + 50 / spot) - 4 + move;

    //Returns the x position of where the circle should be
    return xPosition;
}

/*
 * This method will get the height of 
 * the border of the die and formulate where
 * to place the y position of the numCircle based
 * on value of die and uses spot to determine where
 * to draw circle.
 */
public static int locationY(int yPos, int spot, int move)
{
    //Formula to calculate position of circle
    int yPosition = (yPos + 50 / spot) - 4 + move;

    //Returns the y position of where circle should be
    return yPosition;
}

      public void roll()
      {
         number = Roll.die1();
         repaint();
      }
      //This is where i think im messing up cuz it just replaces the first die
      public void roll2()
      {
        number = Roll.die2();
        repaint();
      }
}

这是获取骰子值的滚动类

---

import java.util.Random;

/*
* This class sets up methods that 
* retrieve what random number is to
* be displayed on the die for each 
* one.
*/
public class Roll 
{
//Sets up var for die1
private static int die1;
//Sets up var for die2
private static int die2;

/*
 * This method creates the die1
 * and it assigns a random number
 * between 1-6 to the die.
 */
public static int die1()
{
    //Create random number generator
    Random gen = new Random();

    //Uses generator to assign number
    die1 = gen.nextInt(6) + 1;

    //Returns die1 value
    return die1;
}


/*
 * This method creates die2 and 
 * assigns a random number between
 * 1-6 to the die.
 */
public static int die2()
{
    //Create random number generator
    Random gen2 = new Random();

    //Uses generator to assign number
    die2 = gen2.nextInt(6) + 1;

    //Returns die2 value
    return die2;
}

/*
 * This method gets the value of both
 * die1 and die2 and adds them together.
 * This will allow the game to decide
 * what bets win and what bets lose.
 */
public static int total()
{
    //Gets die1 and die2 and adds them
    int total = die1 + die2;
    //Returns total value
    return total;
}
}

Answer 1

我认为您需要更改 Die 类并为其提供一个 roll() 方法，它调用 Roe 的 die1() 方法并将数字字段设置为此值并调用重绘。在半伪代码中:

public void roll() {
   Use Roll to get a new int value
   set number field to this new int value
   call repaint on itself
}

然后在 ActionListener 的 actionPerformed(...) 中，在显示的 Die 对象上调用这个新方法。