java - 为单独的对象设置动画

Question

我一直在开发“电梯模拟器”，我必须为“电梯”制作动画。我能够创建不同的电梯对象，这是通过让每个电梯对象都具有宽度、高度和坐标参数来实现的。然后，我将它们全部存储到一个数组中，并使用 JPanel 的 PaintComponent 方法使用 for 循环将它们绘制到我的框架中。

你们能建议一种方法或给我建议来使它们彼此分开动画，比如独立地上下移动它们吗？当我只有一部电梯时，我能够让它移动，但当我尝试将其应用于多部电梯时，它不起作用。

我之前的尝试涉及一个 ActionListener(监听按钮按下以“启动”动画)，它仅更改单个电梯的 x 和 y 坐标。那么我该如何使用多部电梯来做到这一点(电梯的数量对用户来说是任意的)。我是否必须制作与电梯一样多的 ActionListener，以便它可以独立地监听它们？

这是在只有一部电梯时起作用的 ActionListener。它仅向上移动到目前为止。

  private ActionListener timerActionUp = new ActionListener()
{
    private int iterator = 0;
    private int top = 0;
    public void actionPerformed(ActionEvent e)
    {
      if(top<floorQueue.length){
      if(iterator<floorQueue[top]){ //floorQueue is so that the elevator knows where to stop
        if(movefloorup<VERTICALFLOORDISTANCE*6){ //this is when the elevator reaches the "top" floor that can fit into the screen, and moves to the next column representing the floors further up
            repaint();
            movefloorup = movefloorup + VERTICALFLOORDISTANCE;
            System.out.println(movefloorup);
            iterator++;
        }
        else{
            //timer.stop();
            repaint();
            switchmarker = 1; //makes elevator moves to the next column
            movefloorup = 0;
            iterator++;

        }
      }
      else
      {
          System.out.println("Picking up passengers...");
          elevatorCapacity = elevatorCapacity + peopleQueue[floorQueue[top]];
          System.out.println("Passengers in elevator: "+elevatorCapacity);
          peopleQueue[floorQueue[top]] = 0; //Updates the number of people in the elevator
          top++;
          if(elevatorCapacity >= 5)
          {
              System.out.println("WARNING!  ELEVATOR FULL!");
              elevfull = 1;
          }
          //timer.stop();
      }

      }
      else
      {
          System.out.println("Done picking up passengers.");
          timer.stop();
      }



    }
};

非常感谢!

Answer 1

"Do I have to make as many ActionListeners as there are elevators, so it can listen to them independently?"

不，那需要多个计时器。尽可能避免这样做。

"Can you guys suggest a way or give me advice to animate them separately from each other, like say move them up and down independently?"

您应该做的是尝试在 Elevator 类中的方法中实现业务逻辑，然后在循环数组中的所有 Elevators 时调用这些方法。

两个使电梯看起来独立移动，您可以有标志，例如在您的move方法中，例如

public void move() {
    if (move) {
        // do something
    }
}

无论你让电梯移动的原因是什么，这都将是升旗的原因。反之亦然。也许类似于 if (onFloor) { lift.move = false }，可能持续 20 个计时器“迭代”，并在电梯类中保留计数，即当计数达到 20 时将重置回 0，然后 move 将恢复为 true。

<小时/>

这是一个您可以使用的示例。我花了大约20分钟就放弃了。逻辑有点不对劲，但基本上指出了我提到的想法。也许你会有更好的运气。您还可以看到移动不同对象的一个​​很好的工作示例 here

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;

public class ElevatorAnimate extends JPanel {

    private static final int D_W = 300;

    private static final int FLOORS = 6;
    private static final int FLOOR_HEIGHT = 100;
    private static final int BUILDING_HEIGHT = FLOORS * FLOOR_HEIGHT;
    private static final int D_H = BUILDING_HEIGHT;
    private static final int BUILDING_BASE = BUILDING_HEIGHT;
    private static final int ELEVATOR_HEIGHT = 60;
    private static final int ELEVATOR_WIDTH = 30;

    private final List<Elevator> elevators;

    public ElevatorAnimate() {
        elevators = createElevators();

        Timer timer = new Timer(50, new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                for (Elevator el : elevators) {
                    el.move();
                }
                repaint();
            }
        });
        timer.start();
    }

    private List<Elevator> createElevators() {
        List<Elevator> list = new ArrayList<>();
        list.add(new Elevator(6, 30));
        list.add(new Elevator(4, 90));
        list.add(new Elevator(2, 150));
        return list;
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        drawFloors(g);
        for (Elevator el : elevators) {
            el.drawElevator(g);
        }
    }

    private void drawFloors(Graphics g) {
        for (int i = 1; i <= FLOORS; i++) {
            g.drawLine(0, FLOOR_HEIGHT * i, D_W, FLOOR_HEIGHT * i);
        }
    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(D_W, D_H);
    }

    public class Elevator {

        int floor, x, y;
        boolean move = false;
        boolean up = true;
        int stopCount = 0;

        public Elevator(int floor, int x) {
            this.floor = floor;
            y = BUILDING_HEIGHT - (floor * FLOOR_HEIGHT);
            this.x = x;
        }

        public void drawElevator(Graphics g) {
            g.fillRect(x, y, ELEVATOR_WIDTH, ELEVATOR_HEIGHT);
        }

        public void move() {
            if (y <= 0) {
                up = false;
            } else if (y >= BUILDING_BASE + ELEVATOR_HEIGHT) {
                up = true;
            }

            if (isOnFloor()) {
                move = false;
            }

            if (move) {
                if (up) {
                    y -= 2;
                } else {
                    y += 2;
                }
            } else {
                if (stopCount >= 20) {
                    move = true;
                    stopCount = 0;
                } else {
                    stopCount++;
                }
            }
        }

        private boolean isOnFloor() {
            return y / FLOOR_HEIGHT == 100;
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new ElevatorAnimate());
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }
}