自定义视图显示正确，无法在onClick事件后重新绘制（无效）

Question

我在Android中重绘了与无效问题相关的问题。我有一个简单的活动，它创建一个按钮并显示我的自定义视图（drawGrid类）。我试图在onClick事件后重新绘制网格加上一行。我的主要问题是，我如何从drawGrid课程中重新粉饰？任何在正确方向的推动都将在这里受到赞赏。

public class MainActivity extends Activity implements View.OnClickListener {
    DrawGrid drawGrid;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        drawGrid = new DrawGrid(this);
        drawGrid.setBackgroundColor(Color.BLACK);
        setContentView(R.layout.activity_main);
        View ballButton2 = findViewById(R.id.right_btn);
        ballButton2.setOnClickListener(this);
    }

    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.right_btn:
                drawGrid.move();
        }
    }
}

public class DrawGrid extends View {
    int x = 25;
    int y = 25;
    int index = 0;

    public ArrayList<ArrayList<Integer>> playerOneRed = new ArrayList<>(100);
    Paint paint = new Paint();

    public DrawGrid(Context context) {
        super(context);
        paint.setColor(Color.BLUE);
        paint.setStrokeWidth(2);
        this.setBackgroundColor(Color.BLACK);
    }

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

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

    private void init(Context context) {
        paint.setColor(Color.BLUE);
        paint.setStrokeWidth(2);
        this.setBackgroundColor(Color.BLACK);
    }

    @Override
    public void onDraw(Canvas canvas) {
        Log.d("MyApp", "x is " + x);
        paint.setColor(Color.BLUE);
        paint.setStrokeWidth(3);

        for (int i = 0; i < 3000; i = i + 40) {
            canvas.drawLine(i, 0, i, 3000, paint);
        }
        for (int i = 0; i < 3000; i = i + 40) {
            canvas.drawLine(0, i, 3000, i, paint);
        }
        paint.setColor(Color.RED);
        paint.setStrokeWidth(8);

        // canvas.drawLine(0, 1000, 3000, 1000, paint);

        for (ArrayList<Integer> iter : playerOneRed) {
            canvas.drawLine(iter.get(0), iter.get(1), iter.get(2), iter.get(3), paint);
        }
    }

    public void move() {
        playerOneRed.add(new ArrayList<Integer>(4));
        playerOneRed.get(index).add(0);
        playerOneRed.get(index).add(1000);
        playerOneRed.get(index).add(x + 250);
        x = x + 250;
        playerOneRed.get(index).add(1000);

        index++;
        Invalidate();
    }
}