java - 使用计时器绘制在 JFrame 上滚动的图形

Question

我正在制作一个程序，用 Java 图形显示建筑物、一些云彩和树木。我想使用计时器在屏幕上滚动云。我不知道如何使用计时器在到达 JFrame 末尾后不断循环云

计时器处于 126-147

云方法在184 - 239

我尝试将所有计时器代码放入云绘图方法中，但我不知道如何使用与计时器绑定(bind)的变量来使云在云的方法内移动。目前，我只是在方法之外拥有大部分计时器内容，然后使用 3 种不同的云方法，这是多余的。

我对 java 很陌生，如果我有一些基本错误，我很抱歉。

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Elevator extends JFrame implements ActionListener {
    private final int DISPLAY_WIDTH = 800;
    private final int DISPLAY_HEIGHT = 600;

    private JPanel guiPanel, buttonPanel;
    private DisplayPanel display;
    private JLabel Title;
    private JButton Floor;
    private JComboBox Select;


    int locX, locY;
    final int LIMIT = 10;
    final int NUM_ROWS = 10;
    final int WINDOWWIDTH = 12;
    final int WINDOWHEIGHT = 25;
    final int WINDOWSPACING = 10;
    final int FLOORSPACING = 30;
    final int FLOOROFFSET = -10;
    final int ELEVATOR_COLUMN = 5;

    private static final  int NUM_ITERATIONS = 10;  //number of floors for combo box selection
    private int lvlChoice; //variable holding elevator level choice for item event

    private int buildX, buildY, buildW, buildH;  //building height dem

    Color drkGrn = new Color ( 49, 216, 91);   //building ground color
    Color flWind = new Color (163, 156, 77);  //default floor window color
    Color bldCol = new Color (176, 201, 212);  // building color
    Color crntFl = new Color (255, 247, 0);   //current floor color for elevator
    Color blu1 = new Color ( 157, 215, 255 );  //cloud colors
    Color blu2 = new Color (93, 172, 227);
    Color blu3 = new Color ( 62, 167, 240);
    Color blu4 = new Color (136, 156, 169);
    Color blu5 = new Color (209, 230, 245);
    Color plmLeaf = new Color (  6, 145, 84);
    Color trunk =new Color (   170, 85, 0);

    //graphics variables
    final  int tWidth = 10;
    final int tHeiht =120;



    public static void main(String[] args) {
        Elevator frame = new Elevator();
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frame.setLayout(new BorderLayout());

        frame.initializeVariables();

        frame.setUpGUI();
        frame.pack();
        frame.setVisible(true);
    }

    public void initializeVariables() {
        locX = 300;
        locY = 150;
        buildX = locX-20;
        buildY = locY-10;
        buildH =375;
        buildW =250;
        lvlChoice = 1;

    }

    public void setUpGUI() {
        Container window = getContentPane();  //you attach Jcomponents to this pannel
        display = new DisplayPanel();
        guiPanel = new JPanel(new FlowLayout());
        buttonPanel = new JPanel(new FlowLayout());
        //TODO add title panel
       /* Title = new JLabel("Elevator");
        Title.setFont(new Font(" San Serif", Font.PLAIN, 20));
        titlePanel.add(Title);*/

        Floor =new JButton("Floor");
        Floor.addActionListener(this);

        Select = new JComboBox();

        for (int i = 0; i < NUM_ITERATIONS; i++) {
            Select.addItem(String.valueOf(i + 1)); //this takes the int value and the parses it to a string
        }


        buttonPanel.add(Select);
        buttonPanel.add(Floor);


        window.add(buttonPanel, BorderLayout.NORTH);
        window.add(guiPanel, BorderLayout.SOUTH);
        window.add(display, BorderLayout.CENTER);

    }

    //cloude1 timer, moviment
    Timer tm1 = new Timer(60, this);
    int x1 = 800, velX1 = 3; //position of x on cloud and velociity of cloudes

    //cloude1 timer, moviment
    Timer tm2 = new Timer(50, this);
    int x2 = 700, velX2 = 2; //position of x on cloud and velociity of cloudes

    //cloude1 timer, moviment
    Timer tm3 = new Timer(75, this);
    int x3 = 777, velX3 = 2; //position of x on cloud and velociity of cloudes

    @Override
    public void actionPerformed(ActionEvent e) {
        lvlChoice = Integer.parseInt((String) Select.getSelectedItem());
        display.repaint();

        //make only one of these simplfiy the "x1" to x
        x1 = x1 - velX1;  //every 2 milliseconds and 2 to the position of x whitch starts at 0
        x2 = x2 - velX2;  //every 2 milliseconds and 2 to the position of x whitch starts at 0
        x3 = x3 - velX3;  //every 2 milliseconds and 2 to the position of x whitch starts at 0
    }

    class DisplayPanel extends JPanel {
        DisplayPanel() {
            setPreferredSize(new Dimension(DISPLAY_WIDTH, DISPLAY_HEIGHT));
            this.setBackground(Color.WHITE);
        }


        //executes all paint methods
        public void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g;
            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                    RenderingHints.VALUE_ANTIALIAS_ON);

            backDrop(g2d);
            cloud1(g2d, 100, 45);
            cloud3(g2d, 50, 30);
            buildingLoop(g2d);
            cloud2(g2d, 240, 40);
            tree(g2d, 140, 400);
            tree(g2d, 500, 400);
            tree(g2d, 650, 470);
            tree(g2d, 600, 420);
            tree(g2d, 190, 390);
            tree(g2d, 45, 425);
            tree(g2d, 75, 450);
        }

        //static background objects (ground, trees, ect..)
        public void backDrop(Graphics2D g2d) {

            g2d.setColor(drkGrn);
            g2d.fillRect(0,500,getWidth(), getHeight());

        }
        //new method custom for cloudes
        public void cloud1(Graphics2D g2d, int y, int CLDSIZE) {

            //cloud 1
            //y starts at 100 to be put in method argument
            g2d.setColor(blu4);
            g2d.fillOval(x1, y, CLDSIZE, CLDSIZE);
            g2d.setColor(blu1);
            g2d.fillOval(x1 + 15, y-10, CLDSIZE, CLDSIZE);
            g2d.setColor(blu3);
            g2d.fillOval(x1 + 30, y+10, CLDSIZE, CLDSIZE);
            g2d.setColor(blu2);
            g2d.fillOval(x1 + 45, y-10, CLDSIZE, CLDSIZE);
            g2d.setColor(blu5);
            g2d.fillOval(x1 + 57, y, CLDSIZE, CLDSIZE);
            tm1.start(); //start the timer


        }





        public void cloud2(Graphics2D g2d, int y, int CLDSIZE) {
            //cloud 2
            g2d.setColor(blu5);
            g2d.fillOval(x2, y, CLDSIZE,CLDSIZE);
            g2d.setColor(blu4);
            g2d.fillOval(x2+15, y-20, CLDSIZE,CLDSIZE);
            g2d.setColor(blu2);
            g2d.fillOval(x2+30, y+10, CLDSIZE,CLDSIZE);
            g2d.setColor(blu3);
            g2d.fillOval(x2+45, y-20, CLDSIZE,CLDSIZE);
            g2d.setColor(blu1);
            g2d.fillOval(x2+57, y, CLDSIZE,CLDSIZE);
            tm2.start(); //start the timer

        }

        public void cloud3(Graphics2D g2d, int y, int CLDSIZE) {
            //cloud 3
            //y starts at 30
            g2d.setColor(blu3);
            g2d.fillOval(x3, y, CLDSIZE,CLDSIZE);
            g2d.setColor(blu2);
            g2d.fillOval(x3+15, y-10, CLDSIZE,CLDSIZE);
            g2d.setColor(blu4);
            g2d.fillOval(x3+30, y+10, CLDSIZE,CLDSIZE);
            g2d.setColor(blu5);
            g2d.fillOval(x3+45, y-10, CLDSIZE,CLDSIZE);
            g2d.setColor(blu1);
            g2d.fillOval(x3+57, y, CLDSIZE,CLDSIZE);
            tm3.start(); //start the timer

        }

        public void tree(Graphics2D g2d, int xPoint, int yPoint){
            int leafSize =25;

            g2d.setColor(trunk);
            g2d.fillRect(xPoint+25,yPoint,tWidth, tHeiht);

            g2d.setColor(plmLeaf);
            g2d.fillOval(xPoint,yPoint, leafSize, leafSize);
            g2d.fillOval(xPoint+5,yPoint-10, leafSize, leafSize);
            g2d.fillOval(xPoint+5,yPoint+10, leafSize, leafSize);
            g2d.fillOval(xPoint+10,yPoint, leafSize, leafSize);
            g2d.fillOval(xPoint+10,yPoint+10, leafSize, leafSize);
            g2d.fillOval(xPoint+30,yPoint-10, leafSize, leafSize);
            g2d.fillOval(xPoint+30,yPoint+10, leafSize, leafSize);
            g2d.fillOval(xPoint+35,yPoint, leafSize, leafSize);
            g2d.fillOval(xPoint+35,yPoint+10, leafSize, leafSize);

        }


        //building the building and windows for the building
        public void buildingLoop(Graphics2D g2d) {

            g2d.setColor(bldCol);
            g2d.fillRect(buildX, buildY, buildW, buildH);
            g2d.setColor(flWind);
            for (int j = 1; j <=NUM_ROWS; j++) { //draws row
                for (int i = 0; i <= LIMIT; i++) { //draws window's
                    if (i == ELEVATOR_COLUMN && j == NUM_ROWS - lvlChoice + 1) {
                        g2d.setColor(crntFl);
                    }
                    g2d.fillRect (i* (WINDOWWIDTH + WINDOWSPACING) + buildX + WINDOWSPACING, buildY + j * FLOORSPACING - FLOOROFFSET, WINDOWWIDTH , WINDOWHEIGHT);
                    g2d.setColor(flWind);
                }
            }
        }
    }

}

我尝试将所有计时器代码放入云绘图方法中，但我不知道如何使用与计时器绑定(bind)的变量并获取从方法输入的实际参数传递的值.

目前，我只有方法之外的大部分计时器内容，然后使用 3 种不同的云方法，这是多余的。

Answer 1

这是我的写法:如果您有任何疑问，欢迎提问:)

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

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

public class Elevator extends JFrame implements ActionListener
{
    private final int   DISPLAY_WIDTH   = 800;
    private final int   DISPLAY_HEIGHT  = 600;

    private JPanel          guiPanel, buttonPanel;
    private DisplayPanel    display;
    private JLabel          Title;
    private JButton         Floor;
    private JComboBox       Select;

    int         locX, locY;
    final int   LIMIT           = 10;
    final int   NUM_ROWS        = 10;
    final int   WINDOWWIDTH     = 12;
    final int   WINDOWHEIGHT    = 25;
    final int   WINDOWSPACING   = 10;
    final int   FLOORSPACING    = 30;
    final int   FLOOROFFSET     = -10;
    final int   ELEVATOR_COLUMN = 5;

    private static final int    NUM_ITERATIONS  = 10;   // number of floors for combo box selection
    private int                 lvlChoice;              // variable holding elevator level choice for item event

    private int buildX, buildY, buildW, buildH; // building height dem

    Color   drkGrn  = new Color(49, 216, 91);   // building ground color
    Color   flWind  = new Color(163, 156, 77);  // default floor window color
    Color   bldCol  = new Color(176, 201, 212); // building color
    Color   crntFl  = new Color(255, 247, 0);   // current floor color for elevator

    // an array with all your clouds
    private Cloud[] clouds;
    private Tree[]  trees;

    public static void main(String[] args)
    {
        Elevator frame = new Elevator();
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frame.setLayout(new BorderLayout());

        // added the cloud initialization in there
        frame.initializeVariables();

        frame.setUpGUI();
        frame.pack();
        frame.setVisible(true);

        // starts ticking each 30 ms
        frame.tick();
    }

    private void tick()
    {
        // while loop for ever and ever
        while (true)
        {
            // ticks all the clouds
            for (int i = 0; i < clouds.length; i++)
            {
                clouds[i].tick();
            }
            // updates the JFrame graphics
            display.repaint();
            // pauses the ticking for 30 ms
            try
            {
                Thread.sleep(30);
            } catch (InterruptedException e)
            {
            }
        }
    }

    public void initializeVariables()
    {
        locX = 300;
        locY = 150;
        buildX = locX - 20;
        buildY = locY - 10;
        buildH = 375;
        buildW = 250;
        lvlChoice = 1;
        // puts 3 clouds in our array
        clouds = new Cloud[] { new Cloud(800, 100, 45, 3, true), new Cloud(700, 50, 30, 2, false),
                new Cloud(777, 240, 40, 2, false), };
        trees = new Tree[] { new Tree(140, 400), new Tree(500, 400), new Tree(650, 470), new Tree(600, 420),
                new Tree(190, 390), new Tree(45, 425), new Tree(75, 450) };
    }

    public void setUpGUI()
    {
        Container window = getContentPane(); // you attach Jcomponents to this pannel
        display = new DisplayPanel();
        guiPanel = new JPanel(new FlowLayout());
        buttonPanel = new JPanel(new FlowLayout());
        // TODO add title panel
        /* Title = new JLabel("Elevator");
         Title.setFont(new Font(" San Serif", Font.PLAIN, 20));
         titlePanel.add(Title);*/

        Floor = new JButton("Floor");
        Floor.addActionListener(this);

        Select = new JComboBox<>();

        for (int i = 0; i < NUM_ITERATIONS; i++)
        {
            Select.addItem(String.valueOf(i + 1)); // this takes the int value and the parses it to a string
        }

        buttonPanel.add(Select);
        buttonPanel.add(Floor);

        window.add(buttonPanel, BorderLayout.NORTH);
        window.add(guiPanel, BorderLayout.SOUTH);
        window.add(display, BorderLayout.CENTER);

    }

    @Override
    public void actionPerformed(ActionEvent e)
    {
        lvlChoice = Integer.parseInt((String) Select.getSelectedItem());
        display.repaint();

        // moves each cloud by the respective velocity
        for (int i = 0; i < clouds.length; i++)
            clouds[i].x -= clouds[i].velX;
    }

    class DisplayPanel extends JPanel
    {
        private static final long serialVersionUID = 1L;

        DisplayPanel()
        {
            setPreferredSize(new Dimension(DISPLAY_WIDTH, DISPLAY_HEIGHT));
            this.setBackground(Color.WHITE);
        }

        // executes all paint methods
        @Override
        public void paintComponent(Graphics g)
        {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g;
            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

            backDrop(g2d);

            for (Cloud c : clouds)
            {
                if (!c.Foreground) c.draw(g2d);
            }
            buildingLoop(g2d);
            for (Cloud c : clouds)
            {
                if (c.Foreground) c.draw(g2d);
            }
            for (Tree t : trees)
            {
                t.draw(g2d);
            }
        }

        // static background objects (ground, trees, ect..)
        public void backDrop(Graphics2D g2d)
        {

            g2d.setColor(drkGrn);
            g2d.fillRect(0, 500, getWidth(), getHeight());

        }

        // building the building and windows for the building
        public void buildingLoop(Graphics2D g2d)
        {

            g2d.setColor(bldCol);
            g2d.fillRect(buildX, buildY, buildW, buildH);
            g2d.setColor(flWind);
            for (int j = 1; j <= NUM_ROWS; j++)
            { // draws row
                for (int i = 0; i <= LIMIT; i++)
                { // draws window's
                    if (i == ELEVATOR_COLUMN && j == NUM_ROWS - lvlChoice + 1)
                    {
                        g2d.setColor(crntFl);
                    }
                    g2d.fillRect(i * (WINDOWWIDTH + WINDOWSPACING) + buildX + WINDOWSPACING,
                            buildY + j * FLOORSPACING - FLOOROFFSET, WINDOWWIDTH, WINDOWHEIGHT);
                    g2d.setColor(flWind);
                }
            }
        }
    }

}

class Cloud
{
    int x = 800, y, velX = 3; // position of x on cloud and velociity of cloudes

    final Color blu1    = new Color(157, 215, 255); // cloud colors
    final Color blu2    = new Color(93, 172, 227);
    final Color blu3    = new Color(62, 167, 240);
    final Color blu4    = new Color(136, 156, 169);
    final Color blu5    = new Color(209, 230, 245);

    int     Size;
    boolean Foreground;

    public Cloud(int x, int y, int Size, int velX, boolean Foreground)
    {

        this.x = x;
        this.y = y;
        this.Size = Size;
        this.velX = velX;
        this.Foreground = Foreground;

    }

    public void tick()
    {
        x -= velX;
        if (x < -100) x = 1000;
    }

    public void draw(Graphics2D g2d)
    {
        // cloud 1
        // y starts at 100 to be put in method argument
        g2d.setColor(blu4);
        g2d.fillOval(x, y, Size, Size);
        g2d.setColor(blu1);
        g2d.fillOval(x + 15, y - 10, Size, Size);
        g2d.setColor(blu3);
        g2d.fillOval(x + 30, y + 10, Size, Size);
        g2d.setColor(blu2);
        g2d.fillOval(x + 45, y - 10, Size, Size);
        g2d.setColor(blu5);
        g2d.fillOval(x + 57, y, Size, Size);
    }
}

class Tree
{
    int xPoint, yPoint;

    public Tree(int xPoint, int yPoint)
    {
        this.xPoint = xPoint;
        this.yPoint = yPoint;
    }

    public void draw(Graphics2D g2d)
    {
        int leafSize = 25;

        // graphics variables
        final int tWidth = 10;
        final int tHeiht = 120;
        final Color plmLeaf = new Color(6, 145, 84);
        final Color trunk = new Color(170, 85, 0);

        g2d.setColor(trunk);
        g2d.fillRect(xPoint + 25, yPoint, tWidth, tHeiht);

        g2d.setColor(plmLeaf);
        g2d.fillOval(xPoint, yPoint, leafSize, leafSize);
        g2d.fillOval(xPoint + 5, yPoint - 10, leafSize, leafSize);
        g2d.fillOval(xPoint + 5, yPoint + 10, leafSize, leafSize);
        g2d.fillOval(xPoint + 10, yPoint, leafSize, leafSize);
        g2d.fillOval(xPoint + 10, yPoint + 10, leafSize, leafSize);
        g2d.fillOval(xPoint + 30, yPoint - 10, leafSize, leafSize);
        g2d.fillOval(xPoint + 30, yPoint + 10, leafSize, leafSize);
        g2d.fillOval(xPoint + 35, yPoint, leafSize, leafSize);
        g2d.fillOval(xPoint + 35, yPoint + 10, leafSize, leafSize);

    }
}