在Android Studio中更新TextView时防止应用崩溃

Question

晚上好

我是android studio的新手，只是在网上关注随机项目。我已经编写了这个简单的游戏。它将在屏幕上绘制一个红色圆圈，每次您在屏幕上点击时，它将在屏幕的新区域中随机生成一个圆圈。尝试更新Textview时，我正在寻求帮助。文本视图的目的是跟踪圈子中的匹配数。但是，当我找到textview时，加载后应用程序将崩溃。如何在不使应用程序崩溃的情况下更新textview？

public class MainActivity extends AppCompatActivity {


//If I remove this line of code the application will not crash.
TextView score = findViewById(R.id.scoreTextView);

Paint paint;
Path path;
int counter = 0;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new MyView(this));


}


public class MyView extends View {


    Paint paint;
    Path path;


    public MyView(Context context) {
        super(context);
        init();
    }

    public MyView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public MyView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    private void init() {
        paint = new Paint();
        paint.setColor(Color.BLUE);
        paint.setStrokeWidth(10);
        paint.setStyle(Paint.Style.STROKE);

    }


    @Override
    protected void onDraw(Canvas canvas) {
        // TODO Auto-generated method stub
        super.onDraw(canvas);


        float maxx = getWidth();
        float maxy = getHeight();
        float x;
        float y;
        float allowablex;
        float allowabley;
        int radius = 100;

        //random here
        Random rand = new Random();

        x = rand.nextInt((int) (maxx - 1));
        y = rand.nextInt((int) maxy - 1);

        allowablex = maxx - x;
        allowabley = maxy - y;


        if (allowablex > 0) {
            if (allowabley > 0) {
                Paint paint = new Paint();
                paint.setStyle(Paint.Style.FILL);
                paint.setColor(Color.WHITE);
                canvas.drawPaint(paint);
                paint.setColor(Color.parseColor("#da4747"));
                canvas.drawCircle(x, y, radius, paint);
            }
        }


    }


    @Override
    public boolean onTouchEvent(MotionEvent event) {


        int eventAction = event.getAction();


        int x = (int) event.getX();
        int y = (int) event.getY();


        switch (eventAction) {
            case MotionEvent.ACTION_DOWN:
                counter++;

                break;
            case MotionEvent.ACTION_UP:
                counter++;
                break;
            case MotionEvent.ACTION_MOVE:
                counter++;
                break;
        }


        invalidate();


        return super.onTouchEvent(event);

    }
}

}