尝试使用箭头键使形状在一个方向上连续移动 [英] Trying to make the shape continuously move in one direction with arrow keys
问题描述
我正在尝试制作蛇游戏，我在使用JavaFX方面还很陌生.我遇到的问题是，当我使用switch语句根据箭头键更改方向时，它们的矩形仅在按下键时才会移动.我想要的是矩形，它会一直按所按的方向移动，直到按下另一个键为止.我肯定有一个简单的解决方法，对不起，我还是编码和javaFX的新手.
I am attempting to make a snake game an I am fairly new at using JavaFX. The problem I am running into is when I use a switch statement to change the direction based on the arrow keys they rectangle will only move when the key is pressed. What I want is the rectangle to keep moving in the direction pushed until another key is pressed. Im sure there's an easy fix, I'm sorry, I'm still new to coding and javaFX.
import javafx.animation.Animation;
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import javafx.util.Duration;
public class Mess extends Application {
private Stage window;
private final int WIDTH = 500;
private final int HEIGHT = 500;
private Direction snakeDir = Direction.RIGHT;
private int snake_W = 20;
private int snake_H = 20;
private Rectangle snake = new Rectangle(snake_W, snake_H);
private boolean running;
private boolean snakeUp = false;
private boolean snakeRight = true;
private Timeline timeLine = new Timeline();
enum Direction {
LEFT,RIGHT,UP,DOWN,NONE;
}
private Parent createContent() {
Pane root = new Pane();
root.setPrefSize(WIDTH,HEIGHT);
snake.setTranslateX((WIDTH / 4) - (snake.getWidth() / 2));
snake.setTranslateY(HEIGHT / 6);
KeyFrame keyFrame = new KeyFrame(Duration.millis(16), e -> {
if(!running) {return;}
switch(snakeDir) {
case UP:
snake.setTranslateX(snake.getTranslateX());
snake.setTranslateY(snake.getTranslateY() - 4);
break;
case DOWN:
snake.setTranslateX(snake.getTranslateX());
snake.setTranslateY(snake.getTranslateY() + 4);
break;
case LEFT:
snake.setTranslateX(snake.getTranslateX() - 4);
snake.setTranslateY(snake.getTranslateY());
break;
case RIGHT:
snake.setTranslateX(snake.getTranslateX() + 4);
snake.setTranslateY(snake.getTranslateY());
break;
}
});
timeLine.getKeyFrames().add(keyFrame);
timeLine.setCycleCount(Animation.INDEFINITE);
root.getChildren().addAll(snake);
return root;
}
private void startGame() {
running = true;
timeLine.play();
}
private void stopGame() {
timeLine.stop();
running = false;
}
public static void main(String[] args) {
launch(args);
}
@Override
public void start(Stage primaryStage) {
window = primaryStage;
Scene mainScene = new Scene(createContent(),WIDTH,HEIGHT);
mainScene.setOnKeyPressed(e -> {
switch(e.getCode()) {
case UP:
snakeDir = Direction.UP;
break;
case DOWN:
snakeDir = Direction.DOWN;
break;
case LEFT:
snakeDir = Direction.LEFT;
break;
case RIGHT:
snakeDir = Direction.RIGHT;
break;
}
});
mainScene.setOnKeyReleased(e -> {
switch(e.getCode()) {
case UP:
case DOWN:
case LEFT:
case RIGHT:
snakeDir = Direction.NONE;
break;
}
});
window.setTitle("Snake");
window.setScene(mainScene);
window.show();
startGame();
}
}
我希望矩形在按箭头键的方向上连续移动.实际结果是，当按下一个键时，它会移动一次并停止.
I expect the rectangle to continuously move in the direction of the arrow key pushed. The actual result is when a key is pressed it moves once and stops.
推荐答案
以下是我整理的一些代码，可以帮助您入门.按下按钮启动Timeline.按左右箭头键移动圆圈. Timeline每16毫秒循环一次.接近60 FPS.对于这样的游戏，我将更改其值使其达到约40 FPS. 此处是宝贵的资源. 此处是另一种.
Here is some code I put together to get you started. Press the button to start the Timeline. Press left or right arrow key to move the circle. The Timeline loops every 16 millisec. That's close to 60 FPS. I would change the value to get it to about 40 FPS for a game like this. Here is a valuable resource. Here is another.
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.input.KeyCode;
import javafx.scene.layout.Pane;
import javafx.scene.layout.Priority;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
import javafx.util.Duration;
/**
*
* @author guest_account
*/
public class JavaFXApplication1 extends Application {
String input = "";
@Override
public void start(Stage primaryStage) {
Circle circle = new Circle(700 / 2, 700 / 2, 15, Color.BLUE);
Timeline timeline = new Timeline(new KeyFrame(Duration.millis(16), (ActionEvent event) -> {
if(input.equals(KeyCode.RIGHT.toString()))
{
circle.setCenterX(circle.getCenterX() + 10);
}
if(input.equals(KeyCode.LEFT.toString()))
{
circle.setCenterX(circle.getCenterX() - 10);
}
if(input.equals(KeyCode.UP.toString()))
{
circle.setCenterY(circle.getCenterY() - 10);
}
if(input.equals(KeyCode.DOWN.toString()))
{
circle.setCenterY(circle.getCenterY() + 10);
}
}));
timeline.setCycleCount(Timeline.INDEFINITE);
Button btn = new Button();
btn.setText("Play");
btn.setOnAction((ActionEvent event) -> {
timeline.play();
btn.setDisable(true);
});
Pane boardRoot = new Pane(circle);
VBox.setVgrow(boardRoot, Priority.ALWAYS);
VBox root = new VBox(boardRoot, btn);
Scene scene = new Scene(root, 700, 700);
scene.setOnKeyPressed(keyEvent ->{
input = keyEvent.getCode().toString();
});
primaryStage.setTitle("Hello World!");
primaryStage.setScene(scene);
primaryStage.show();
}
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
}
在6/8/2019评论后更新代码
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