Question

因此，每当我尝试运行我的应用程序时，我都会遇到很多错误，但如果我从create方法中删除model代码，应用程序将运行没有任何问题。

我想做的是做一个记忆游戏并将存储卡添加到场景中，这样你就可以用图形方式看到这些卡片。

public class memory3 extends Application {

private Cards card;
private Model model;

private Parent create(){
    Pane root = new Pane();
    root.setPrefSize(1280, 720);

    model = new Model("Ben", "Jerry", 10);


    ArrayList<Cards> cards = model.getCards();
    List<Tile> tiles = new ArrayList<>();

    for (Cards card1 : cards) {
        tiles.add(new Tile(card1.getValue()));
    }

    return root;
}

@Override
public void start(Stage primaryStage) {

    primaryStage.setTitle("Memory");
    primaryStage.setScene(new Scene(create()));
    primaryStage.show();
}

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    launch(args); 
}

}

模型构造函数，设置游戏：

 public Model(String name1, String name2, int pairs){
        player1 = name1;
        player2 = name2;
        score1 = 0;
        score2 = 0;

        char c = 'A';

        for(int i = 0; i < pairs; i++){
            cards.add(new Cards(c));
            cards.add(new Cards(c));
            c++;
        }

        //Shuffle cards
        Collections.shuffle(cards);
    }

Tile class，以图形方式创建存储卡：

public class Tile extends StackPane{
private Text text = new Text();

public Tile(char value){
    Rectangle border = new Rectangle(50,50);
    border.setFill(null);
    border.setStroke(Color.BLACK);

    text.setText(String.valueOf(value));
    text.setFont(Font.font(30));

    setAlignment(Pos.CENTER);
    getChildren().addAll(border, text);
}

}

错误：

Executing C:\Java Objektorienterad\memory33\memory3\dist\run1052614504\memory3.jar using platform C:\Program Files\Java\jdk1.8.0_101\jre/bin/java
Exception in Application start method
java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
    at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$155(LauncherImpl.java:182)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
    at model.Model.<init>(Model.java:32)
    at view.memory3.create(memory3.java:32)
    at view.memory3.start(memory3.java:49)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$162(LauncherImpl.java:863)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$175(PlatformImpl.java:326)
    at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
    ... 1 more
Exception running application view.memory3

JavaFx应用程序在启动时会出错

0 个答案: