Question

我的游戏有问题。我有一个主要活动，它显示了我绘制游戏的表面视图。现在我想将数据从我的主要活动传递给一个类，但每次我尝试这个我得到一个错误，在LogCat中我看到错误发生在我传递数据的行上。我的代码 MainActivity：

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.main);
}
public boolean onTouchEvent(MotionEvent event) {
            currentX = event.getX();
    currentY = event.getY();
    if(event.getAction() == MotionEvent.ACTION_DOWN){
        touchDisplay = true;
        banka = new Banka(currentX, currentY, touchDisplay);
    }
    if(event.getAction() == MotionEvent.ACTION_UP){
        touchDisplay = false;
        banka = new Banka(currentX, currentY, touchDisplay);
    }
    return super.onTouchEvent(event);
}

收到数据的类：

public class Banka {
public GameView gameView;

public float currentX = 0;
public float currentY = 0;
public boolean touchDownTrue = false;

public Banka (float x, float y, boolean touch){
    this.currentX = x;
    this.currentY = y;
    this.touchDownTrue = touch;
    gameView.isReady();
}

这里是我的LogCat错误：

这里是logcat：

线程以未捕获的异常退出（group = 0x4001b188）未捕获 handler：由于未捕获的异常，线程主要退出 java.lang.NullPointerException at com.whlabs.nameless.Banka。（Banka.java:14）at com.whlabs.nameless.MainActivity.onTouchEvent（MainActivity.java:31）at at android.app.Activity.dispatchTouchEvent（Activity.java:2064）at com.android.internal.policy.impl.PhoneWindow $ DecorView.dispatchTouchEvent（PhoneWindow.java:1643）在android.view.ViewRoot.handleMessage（ViewRoot.java:1691）at android.os.Handler.dispatchMessage（Handler.java:99）at android.os.Looper.loop（Looper.java:123）at android.app.ActivityThread.main（ActivityThread.java:4363）at java.lang.reflect.Method.invokeNative（Native Method）at java.lang.reflect.Method.invoke（Method.java:521）at com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:860）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:618）at dalvik.system.NativeStart.main（原生方法）

Answer 1

我猜你得到了NullPointerException，因为你没有初始化gameView。解决此问题的一种方法是在构造函数中初始化gameView，如下所示：

public Banka (float x, float y, boolean touch){
    this.currentX = x;
    this.currentY = y;
    this.touchDownTrue = touch;
    gameView = new GameView();
    gameView.isReady();
}

将数据从活动传递到类

1 个答案: