Java paintComponent()可以在AbstractAction类中使用吗?
我正在尝试制作一个创建JPanel的程序,当用户按下W、a、S和D时,绘制的立方体将在窗口中四处导航(每次按下一个键时按一定量),我创建了MoveCubeUp类,并重写其中的paintComponent方法,以便在调用立方体时重新绘制立方体,但这是行不通的。有人能解释一下原因吗Java paintComponent()可以在AbstractAction类中使用吗?,java,swing,animation,abstract-action,Java,Swing,Animation,Abstract Action,我正在尝试制作一个创建JPanel的程序,当用户按下W、a、S和D时,绘制的立方体将在窗口中四处导航(每次按下一个键时按一定量),我创建了MoveCubeUp类,并重写其中的paintComponent方法,以便在调用立方体时重新绘制立方体,但这是行不通的。有人能解释一下原因吗 public MyPanel(){ … MoveSquareUp m=new MoveSquareUp(squareX, squareY); getInputMap().put(KeyStroke
public MyPanel(){
…
MoveSquareUp m=new MoveSquareUp(squareX, squareY);
getInputMap().put(KeyStroke.getKeyStroke(("W"), "pressed"));
getActionMap().put("pressed", m)
}
class MoveSquareUp extends AbstractAction{
public int squareXX, squareYY;
public moveSquare(){
squareXX=squareX+5;
}
//I define the paintComponent method to draw the rectangle with its set height
//at squareXX, squareYY
//action method is null (I am still trying to figure out binding keys to
//actions but the paintComponent not working is preventing that
}
如果格式不好,我很抱歉。第一个职位:/
是否需要在扩展JFrame的类中定义paint方法,如果需要,我如何将其用于abstractAction类(或者如何完全避免abstractAction类)?问题的关键在于,您需要学会将模型与视图和控件分开。在这里,模型是精灵的位置,视图是绘制此位置的GUI,控件将保存包括AbstractAction在内的操作,如果可能,它们都应该彼此分离 因此,为了回答您的直接问题,任何paintComponent都不应该位于抽象操作内部,因为前者是视图的关键部分,而后者是控件的关键部分。相反,让视图反映模型的状态,模型的状态将由控件(操作)更改 关于你的另一个问题,所有的绘制方法都应该是JFrame的一部分吗:所有的绘制方法都不应该在扩展JFrame的类中,因为这个类是一个复杂的类,它创建了一个顶级窗口和几个子组件来显示你的GUI,如果你覆盖了它的绘制,子零部件的绘制效果可能不好。而是在扩展JPanel的类的paintComponent方法中绘制,然后在JFrame中显示此对象 例如:
package pkg3;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.EnumMap;
import java.util.HashMap;
import java.util.Map;
public class GamePanel extends JPanel {
private static final int ANIMATION_DELAY = 15;
private final int HEIGHT = 400;
private final int WIDTH = 600;
private Square square;
private EnumMap<Direction, Boolean> dirMap = new EnumMap<>(Direction.class);
private Map<Integer, Direction> keyToDir = new HashMap<>();
// !! private Circle circle;
private Timer animationTimer;
public GamePanel() {
for (Direction dir : Direction.values()) {
dirMap.put(dir, Boolean.FALSE);
}
keyToDir.put(KeyEvent.VK_UP, Direction.UP);
keyToDir.put(KeyEvent.VK_DOWN, Direction.DOWN);
keyToDir.put(KeyEvent.VK_LEFT, Direction.LEFT);
keyToDir.put(KeyEvent.VK_RIGHT, Direction.RIGHT);
setKeyBindings();
setBackground(Color.white);
setPreferredSize(new Dimension(WIDTH, HEIGHT));
setFocusable(true);
square = new Square();
animationTimer = new Timer(ANIMATION_DELAY, new AnimationListener());
animationTimer.start();
}
private void setKeyBindings() {
int condition = WHEN_IN_FOCUSED_WINDOW;
final InputMap inputMap = getInputMap(condition);
final ActionMap actionMap = getActionMap();
boolean[] keyPressed = { true, false };
for (Integer keyCode : keyToDir.keySet()) {
Direction dir = keyToDir.get(keyCode);
for (boolean onKeyPress : keyPressed) {
boolean onKeyRelease = !onKeyPress; // to make it clear how
// bindings work
KeyStroke keyStroke = KeyStroke.getKeyStroke(keyCode, 0, onKeyRelease);
Object key = keyStroke.toString();
inputMap.put(keyStroke, key);
actionMap.put(key, new KeyBindingsAction(dir, onKeyPress));
}
}
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
square.display(g);
}
private class AnimationListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent evt) {
boolean repaint = false;
for (Direction dir : Direction.values()) {
if (dirMap.get(dir)) {
square.move(dir);
repaint = true;
}
}
if (repaint) {
repaint();
}
}
}
private class KeyBindingsAction extends AbstractAction {
private Direction dir;
boolean pressed;
public KeyBindingsAction(Direction dir, boolean pressed) {
this.dir = dir;
this.pressed = pressed;
}
@Override
public void actionPerformed(ActionEvent evt) {
dirMap.put(dir, pressed);
}
}
private static void createAndShowGUI() {
GamePanel gamePanel = new GamePanel();
JFrame frame = new JFrame("GamePanel");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(gamePanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
gamePanel.requestFocusInWindow();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
enum Direction {
UP(0, -1), DOWN(0, 1), LEFT(-1, 0), RIGHT(1, 0);
private int incrX;
private int incrY;
private Direction(int incrX, int incrY) {
this.incrX = incrX;
this.incrY = incrY;
}
public int getIncrX() {
return incrX;
}
public int getIncrY() {
return incrY;
}
}
class Square {
private int x = 0;
private int y = 0;
private int w = 20;
private int h = w;
private int step = 1;
private Color color = Color.red;
private Color fillColor = new Color(255, 150, 150);
private Stroke stroke = new BasicStroke(3f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
public void display(Graphics g) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(fillColor);
g2d.fillRect(x, y, w, h);
g2d.setStroke(stroke);
g2d.setColor(color);
g2d.drawRect(x, y, w, h);
g2d.dispose();
}
public void setStep(int step) {
this.step = step;
}
public void move(Direction dir) {
x += step * dir.getIncrX();
y += step * dir.getIncrY();
}
}
pkg3包;
导入java.awt.*;
导入javax.swing.*;
导入java.awt.event.*;
导入java.util.EnumMap;
导入java.util.HashMap;
导入java.util.Map;
公共类游戏面板扩展了JPanel{
专用静态最终int动画_延迟=15;
私人最终内部高度=400;
专用最终整数宽度=600;
私人广场;
私有EnumMap dirMap=新EnumMap(Direction.class);
私有映射keyToDir=newhashmap();
//!!私人圈子;
私人定时器动画定时器;
公共游戏小组(){
for(Direction dir:Direction.values()){
dirMap.put(dir,Boolean.FALSE);
}
keyToDir.put(KeyEvent.VK_UP,Direction.UP);
keyToDir.put(KeyEvent.VK_DOWN,Direction.DOWN);
keyToDir.put(KeyEvent.VK_左,Direction.LEFT);
keyToDir.put(KeyEvent.VK_RIGHT,Direction.RIGHT);
setKeyBindings();
挫折地面(颜色:白色);
setPreferredSize(新尺寸(宽度、高度));
设置聚焦(真);
正方形=新正方形();
animationTimer=新计时器(ANIMATION_DELAY,new AnimationListener());
animationTimer.start();
}
私有void setKeyBindings(){
int condition=当在聚焦窗口中时;
最终InputMap InputMap=getInputMap(条件);
final ActionMap ActionMap=getActionMap();
布尔[]键按下={true,false};
for(整数键代码:keyToDir.keySet()){
Direction dir=keyToDir.get(keyCode);
用于(布尔onKeyPress:keyPressed){
boolean onKeyRelease=!onKeyPress;//说明如何
//绑定工作
击键击键=击键。getKeyStroke(keyCode,0,onKeyRelease);
Object key=keyStroke.toString();
inputMap.put(击键,键);
put(key,newkeybindingsaction(dir,onKeyPress));
}
}
}
公共组件(图形g){
超级组件(g);
方形显示器(g);
}
私有类AnimationListener实现ActionListener{
@凌驾
已执行的公共无效操作(操作事件evt){
布尔重绘=假;
for(Direction dir:Direction.values()){
if(dirMap.get(dir)){
方。移动(直接);
重新绘制=真;
}
}
如果(重新喷漆){
重新油漆();
}
}
}
私有类KeyBindingsAction扩展了AbstractAction{
私人指导主任;
布尔按下;
公钥绑定操作(方向方向,按布尔值){
this.dir=dir;
this.pressed=pressed;
}
@凌驾
已执行的公共无效操作(操作事件evt){
dirMap.put(dir,按下);
}
}
私有静态void createAndShowGUI(){
GamePanel GamePanel=新建GamePanel();
JFrame=新JFrame(“游戏面板”);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(游戏面板);
frame.pack();
frame.setLocationRelativeTo(空);
frame.setVisible(true);
gamePanel.requestFocusInWindow();
}
公共静态void main(字符串[]args){
SwingUtilities.invokeLater(新的Runnable(){
公开募捐{
createAndShowGUI();
}
});
}
}
枚举方向{
向上(0,-1),向下(0,1),左(-1,0),右(1,0);
私人int incrX;
私营企业;
私人方向(内部控制,内部控制){
this.incrX=incrX;
this.incrY=incrY;
}
public int getIncrX(){
返回incrX;
}
public int getIncrY(){
返回incrY;
}
}
阶级广场{
私有整数x=0;
私有整数y=0;
私人int w=20;
私有int h=w;
私有整数步长=1;
私有颜色=Color.red;
私有颜色fillColor=新颜色(255、150、150);
私人住宅