我正在尝试移动imageView。即使脉冲仍在将我的怪物移动到我的mannetje，我总是得到一个空指针异常。我认为问题是我制作了一个新的控制器。如何在不创建新控制器的情况下调用方法或修复空指针异常。
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.input.KeyEvent;
import javafx.stage.Stage;
public class main2 extends Application{
public void start(Stage primaryStage) throws Exception{
Parent root = FXMLLoader.load(getClass().getResource("setup.fxml"));
primaryStage.setTitle("TFOA");
Scene scene = new Scene(root);
primaryStage.setScene(scene);
primaryStage.show();
controller control = new controller();
scene.setOnKeyPressed(new EventHandler<KeyEvent>() {
@Override
public void handle(KeyEvent event) {
switch (event.getCode()) {
case UP: control.up(); break;
case DOWN: control.up(); break;
case LEFT: control.up(); break;
case RIGHT: control.up(); break;
}
}
});
scene.setOnKeyReleased(new EventHandler<KeyEvent>() {
@Override
public void handle(KeyEvent event) {
switch (event.getCode()) {
case UP: control.up(); break;
case DOWN: control.up(); break;
case LEFT: control.up(); break;
case RIGHT: control.up(); break;
}
}
});
}
public static void main(String[] args) {
launch(args);
}
这是我的主要
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.event.ActionEvent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.input.KeyEvent;
import javafx.scene.layout.AnchorPane;
import javafx.scene.paint.Color;
import javafx.scene.paint.Paint;
import javafx.scene.shape.Circle;
import javafx.util.Duration;
public class controller{
public Button newGame;
public Button cont;
public AnchorPane pane;
public ImageView mannetje;
public Circle monster;
public Scene scene;
public Image boat;
public Label hitpoints;
Hero hero;
Monster monsterChar;
private Timeline timeline;
private int countdown = 15;
public void initialize(){
timeline = new Timeline(new KeyFrame(Duration.seconds(0.7),ob -> puls()));
timeline.setCycleCount(15000);
}
private void puls() {
if(mannetje.getLayoutX()<monster.getLayoutX() && mannetje.getLayoutY() == monster.getLayoutY()){ // LEFT
monster.setLayoutX(monster.getLayoutX()-10);
if((mannetje.getLayoutX()+mannetje.getFitWidth()+(monster.getRadius()/2))>monster.getLayoutX()){
monsterChar.hit(hero);
}
}
if(mannetje.getLayoutX()<monster.getLayoutX() && mannetje.getLayoutY() < monster.getLayoutY()){ // LEFT-UP
monster.setLayoutX(monster.getLayoutX()-10);
monster.setLayoutY(monster.getLayoutY()-10);
}
if(mannetje.getLayoutX()==monster.getLayoutX() && mannetje.getLayoutY() < monster.getLayoutY()){ // DOWN
monster.setLayoutY(monster.getLayoutY()+10);
if((mannetje.getLayoutY()-mannetje.getFitHeight()-(monster.getRadius()/2))>monster.getLayoutY()){
monsterChar.hit(hero);
}
}
if(mannetje.getLayoutX()==monster.getLayoutX() && mannetje.getLayoutY() > monster.getLayoutY()){ // UP
monster.setLayoutY(monster.getLayoutY()-10);
if((mannetje.getLayoutY()+mannetje.getFitHeight()+(monster.getRadius()/2))>monster.getLayoutY()){
monsterChar.hit(hero);
}
}
if(mannetje.getLayoutX()>monster.getLayoutX() && mannetje.getLayoutY() > monster.getLayoutY()){ // RIGHT-UP
monster.setLayoutX(monster.getLayoutX()+10);
monster.setLayoutY(monster.getLayoutY()+10);
}
if(mannetje.getLayoutX()>monster.getLayoutX() && mannetje.getLayoutY() < monster.getLayoutY()){ // RIGHT-DOWN
monster.setLayoutX(monster.getLayoutX()+10);
monster.setLayoutY(monster.getLayoutY()-10);
}
if(mannetje.getLayoutX()<monster.getLayoutX() && mannetje.getLayoutY() > monster.getLayoutY()){ //LEFT-DOWN
monster.setLayoutX(monster.getLayoutX()-10);
monster.setLayoutY(monster.getLayoutY()+10);
}
if(mannetje.getLayoutX()>monster.getLayoutX() && mannetje.getLayoutY() == monster.getLayoutY()){ // RIGHT
monster.setLayoutX(monster.getLayoutX()+10);
if((mannetje.getLayoutX()-(mannetje.getFitWidth()/2))<monster.getLayoutX()){
monsterChar.hit(hero);
}
}
}
public void newGame(){
cont.setVisible(false);
newGame.setVisible(false);
pane.setStyle("-fx-background-image: url('map.jpg');");
//System.out.println(mannetje);
mannetje.setVisible(true);
monster.setVisible(true);
hitpoints.setVisible(true);
//moveCircleOnKeyPress();
System.out.println(mannetje);
//boat.setImage(null);
//boat.setStyle("-fx-text-fill: white;");
hero = new Hero("Klud" , 1500);
monsterChar = new Monster("Chak Al Ghui",50,7);
hitpoints.setText(hero.getName() + ": " + hero.getEffectiveHitpoints()+" "+monsterChar.getName()+": "+ monsterChar.getEffectiveHitpoints() ) ;
Weapon lition = new Weapon(2,"Lition");
lition.setDamage(7);
Armor faciate = new Armor(10,"Faciate");
faciate.setEffectiveProtection(1);
Backpack backpack = new Backpack(1, "Backpack",500);
hero.equip(backpack, Anchor.back);
hero.equip(lition, Anchor.rightHand);
hero.equip(faciate, Anchor.body);
timeline.playFromStart();
mannetje.setLayoutY(200);
monster.setLayoutY(200);
}
public void up(){
mannetje.setLayoutY(mannetje.getLayoutY()-25);
}
public void left(){
mannetje.setLayoutX(mannetje.getLayoutX()-25);
}
public void right(){
mannetje.setLayoutX(mannetje.getLayoutX()+25);
}
public void down(){
mannetje.setLayoutY(mannetje.getLayoutY()+25);
}
public void hit(){
if((mannetje.getLayoutX()+mannetje.getFitWidth()+monster.getRadius())>monster.getLayoutX()){
hero.hit(monsterChar);
}
else{
}
hitpoints.setText(hero.getName() + ": " + hero.getEffectiveHitpoints()+" "+monsterChar.getName()+": "+ monsterChar.getEffectiveHitpoints() ) ;
}
}
这是控制器类。