.setOnClickListener（本）;导致应用崩溃

Question

目前正在开发针对Android的tic tac toe游戏。我正在使用GameView，我遇到的问题是每次运行我的应用程序时都会崩溃，因为.setOnClickListener（this）;如果有人有任何有用的提示，那将是伟大的。 附：按钮A1已放置在布局上。

public class GameView extends View implements View.OnClickListener {

    private Paint bluePaint, redPaint;
    private Bitmap a1Tile, a2Tile, a3Tile, b1Tile, b2Tile, b3Tile, c1Tile, c2Tile, c3Tile;
    boolean playerTurn = true;
    int playerTurnCount = 0;
    private Button A1;
    Button[] btnGridArray;

    public GameView(Context context) {
        super(context);
        bluePaint = new Paint();
        redPaint = new Paint();
        bluePaint.setColor(Color.BLUE);
        redPaint.setColor(Color.RED);

        a1Tile = BitmapFactory.decodeResource(getResources(),R.drawable.a1tile);
        a2Tile = BitmapFactory.decodeResource(getResources(),R.drawable.a2tile);
        a3Tile = BitmapFactory.decodeResource(getResources(),R.drawable.a3tile);

        b1Tile = BitmapFactory.decodeResource(getResources(),R.drawable.b1tile);
        b2Tile = BitmapFactory.decodeResource(getResources(),R.drawable.b2tile);
        b3Tile = BitmapFactory.decodeResource(getResources(),R.drawable.b3tile);

        c1Tile = BitmapFactory.decodeResource(getResources(),R.drawable.c1tile);
        c2Tile = BitmapFactory.decodeResource(getResources(),R.drawable.c2tile);
        c3Tile = BitmapFactory.decodeResource(getResources(),R.drawable.c3tile);

        A1 = (Button)findViewById(R.id.a1Btn);

        btnGridArray = new Button[]{A1};

        for(Button btn : btnGridArray){
            btn.setOnClickListener(this);
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        //canvas.drawRect(100,100,100, 80, bluePaint);
        canvas.drawBitmap(a1Tile, 60, 80, null);
        canvas.drawBitmap(a2Tile, 280, 80, null);
        canvas.drawBitmap(a3Tile, 500, 80, null);
        canvas.drawBitmap(b1Tile, 60, 280, null);
        canvas.drawBitmap(b2Tile, 280, 280, null);
        canvas.drawBitmap(b3Tile, 500, 280, null);
        canvas.drawBitmap(c1Tile, 60, 480, null);
        canvas.drawBitmap(c2Tile, 280, 480, null);
        canvas.drawBitmap(c3Tile, 500, 480, null);
        redPaint.setTextSize(72);
    }

    @Override
    public void onClick(View v){
        Button btn = (Button) v;
        btnClicked(btn);
    }

    public void btnClicked(Button btn){
        if(playerTurn){
            btn.setText("X");
            btn.setTextSize(25);
        }else{
            btn.setText("O");
            btn.setTextSize(25);
        }
        playerTurn = !playerTurn;
    }
}