JavaFX：单击按钮后游戏场景不会更新

Question

我有一个Main，Cell和Displayer类。Main 创建一个Cell[][]网格，将其传递给构造Panes 并返回游戏Scene的Displayer。

我有一个deleteCells按钮，可以在类Main调用deleteCells方法。但是，在我按下它之后，即使输出证明该方法已执行System.out.printlnScene也不会更新：

单元格：

public class Cell {
private boolean status;
public Cell()  {
System.out.println("DEAD CELL CREATED");
status = false;
}
public boolean getStatus()  {
return status;
}
public void setStatus(boolean status)  {
this.status = status;
}
}

主：

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.stage.Stage;
import java.util.Random;
public class Main extends Application {
private static int  gameWidth= 800;
private static int gameHeight=600;
private static int gridSize = 20;
private static Cell[][] grid = new Cell[gridSize][gridSize];
private static Scene scene;
private static Displayer gameDisplayer;    
@Override
public void start(Stage primaryStage) throws Exception{
primaryStage.setTitle("Advanced Game of Life");
createGrid();
gameDisplayer = new Displayer(gameWidth, gameHeight, grid);
scene = gameDisplayer.getGameScene();
primaryStage.setScene(scene);
primaryStage.show();
}

public static void main(String[] args) {
launch(args);
}
private static void createGrid()  {
for (int i=0; i<gridSize; i++)  {
for (int j=0; j<gridSize; j++)
grid[i][j] = new Cell();
}
}
public static void deleteCells()  {
for (int i=0; i<gridSize; i++)  {
for (int j=0; j<gridSize; j++) {
grid[i][j].setStatus(false);
}
}
//scene = gameDisplayer.getGameScene();  //this doesn't work
}
public static void createCell()  {
Random rand = new Random();
}
}

播放器：

import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
public class Displayer  implements EventHandler<ActionEvent> {
private static Color ALIVE_COLOR=Color.GREEN;
private static Color DEAD_COLOR=Color.SILVER;;
private static BorderPane gamePane;
private static Pane cellsPane;
private HBox buttonsPane;
private Pane statsPane;
private Pane setupsPane;
private HBox bottomPane;
Button createCellButton;
Button deleteCellsButton;
Label cellsCountLabel;
Label setupsLabel;
private int  gameWidth;
private int gameHeight;
static int gridSize = 20;
static int cellId = 1;
private Cell[][] gameGrid;
private Scene gameScene;
public Displayer(int width, int height, Cell[][] grid)  {
gameWidth = width;
gameHeight = height;
gameGrid=grid;
createPanes();
createButtons();
createLabels();
setPaneStyles();
setButtonsStyles();
setLabelsStyles();

gameScene = new Scene(gamePane, gameWidth, gameHeight);
}
public Scene getGameScene()  {
return gameScene;
}
private void createPanes()  {
gamePane = new BorderPane();
buttonsPane = new HBox(5);
statsPane = new Pane();
cellsPane = makeGridPane(gameGrid);
setupsPane = new Pane();
bottomPane = new HBox(5);
}
private void createButtons()  {
createCellButton = new Button();
deleteCellsButton = new Button();
}
private void createLabels()  {
cellsCountLabel = new Label("Cells Count: " + (cellId + 1));
setupsLabel = new Label("Setups Label");
}

private void setPaneStyles()  {...}
private void setButtonsStyles()  {...}
private void setLabelsStyles()  {...}
public void handle(ActionEvent event)  {
if (event.getSource()==createCellButton)  {
//Main.createCell();
}
else if (event.getSource() == deleteCellsButton) {
Main.deleteCells();
cellsCountLabel.setText("Cells Count: " + (cellId + 1));
System.out.println("Cells deleted");
}
else  {
System.out.println("Unknown button");
}
}
public Pane makeGridPane(Cell[][] grid) {
Pane gridPane = new Pane();
for(int i=0; i<gridSize; i++){
for(int j=0; j<gridSize; j++){
Rectangle rect = new Rectangle();
System.out.println("grid[" + i + "][" + j +"]");
if (grid[i][j].getStatus())  {
rect.setFill(ALIVE_COLOR);
}
else {
rect.setFill(DEAD_COLOR);
}
rect.setStroke(Color.BLACK);
rect.setX(i * gridSize);
rect.setY(j * gridSize);
rect.setWidth(gridSize);
rect.setHeight(gridSize);
rect.setOnMouseClicked(new EventHandler<MouseEvent>(){
@Override
public void handle(MouseEvent me){
rect.setFill(Color.RED);
}
});
gridPane.getChildren().add(rect);

}
}
return gridPane;
}
}

有没有办法使Scene本身更新，即使它是在Displayer内部构造的，并且按钮调用Main类中的方法？我尝试在方法中添加scene = gameDisplayer.getGameScene();deleteCells()但没有改变情况。我应该如何根据 MVC 处理用户的输入，以便Scene响应更改，因为所有 GUI 元素都位于单独的类Displayer？

编辑：

添加了editGrid()方法以Main：

public static void editGrid(int x, int y, boolean status)  {
grid[x][y].setStatus(status);
}

更新Displayer内部setOnMouseClicked：

rect.setOnMouseClicked(new EventHandler<MouseEvent>(){
@Override
public void handle(MouseEvent me){
Main.editGrid ((int) rect.getX()/gridSize, (int) rect.getY()/gridSize, true);
}
});

Answer 1

在传统的MVC中，模型是"可观察的"，从某种意义上说，观察者可以注册以接收数据更改的通知。视图(或控制器，具体取决于您使用的 MVC 模式的变体)观察模型中的数据，并在数据更改时相应地更新 UI 组件。

JavaFX通过定义属性和绑定API使做到这一点变得非常容易。这些属性类可以直接观察，在事件更改时触发事件以ChangeListener，并且绑定 API 允许您表示变量之间的依赖关系。UI 组件本身是使用这些属性编写的。

因此，您可以将模型实现为

public class Cell {
private final BooleanProperty status;
public Cell()  {
System.out.println("DEAD CELL CREATED");
status = new SimpleBooleanProperty(false);
}
public BooleanProperty statusProperty() {
return status ;
}
public final boolean getStatus()  {
return statusProperty().get();
}
public final void setStatus(boolean status)  {
statusProperty().set(status);
}
}

然后，您需要做的就是在相应单元格的状态更改时更新矩形的颜色：

public Pane makeGridPane(Cell[][] grid) {
Pane gridPane = new Pane();
for(int i=0; i<gridSize; i++){
for(int j=0; j<gridSize; j++){
Rectangle rect = new Rectangle();
System.out.println("grid[" + i + "][" + j +"]");
if (grid[i][j].getStatus()) {
rect.setFill(ALIVE_COLOR);
} else {
rect.setFill(DEAD_COLOR);
}
grid[i][j].statusProperty().addListener((obs, oldStatus, newStatus) -> {
if (newStatus) {
rect.setFill(ALIVE_COLOR);
} else {
rect.setFill(DEAD_COLOR);
}
});
rect.setStroke(Color.BLACK);
rect.setX(i * gridSize);
rect.setY(j * gridSize);
rect.setWidth(gridSize);
rect.setHeight(gridSize);

rect.setOnMouseClicked(new EventHandler<MouseEvent>(){
@Override
public void handle(MouseEvent me){
rect.setFill(Color.RED);
}
});
gridPane.getChildren().add(rect);

}
}
return gridPane;
}