Android-如何在onDraw（Canvas）内正确调用intent（activity）？

Question

I'm trying to call an intent inside the canvas but it doesn't seem to work the way I thought it should be. What I have in mind is when it passes through the startactivity() , then that's it, it exits the canvas right away but I was wrong.

Flow should be:

Menu -> Pong(Activity) -> Canvas -> Game_Over

What's happening:

Menu -> Pong(Activity) -> Canvas(screen stuck here) -> Game_Over(iterates unknown times)

Sometimes it crashes and won't proceed to Game_Over.

Inside my onDraw() is the code below when the Game Over condition is met:

Intent i = new Intent(getContext(), GameOver.class);
i.putExtra("score", Integer.toString(ball.getScore()));
i.putExtra("level", Integer.toString(ball.getLevel()));
getContext().startActivity(i);

From what I've observed after making the scores, it seems to be looping for like 20+ times since the toast for the "High Score" found in the next activity won't stop and the screen is stuck at the canvas until the loop stops. This gave me a clue that the activity to be called is looping countless times.

Who's at fault here? Is it the onDraw() for redrawing even though it started the startActivity() already? If yes, how do I stop onDraw() from looping before it reaches intent so it won't loop the next activity?

Here's my onDraw() :

public void onDraw(Canvas canvas) {
    // Background
    canvas.drawColor(Color.DKGRAY);

    // Score
    canvas.drawText("Score: " + Integer.toString(ball.getScore()), 25, 50,
            paint);

    // Level
    canvas.drawText("Level: " + Integer.toString(ball.getLevel()), 25, 100,
            paint);

    // =========================
    // Draw Paddle
    // paint.setColor(Color.parseColor("#AA00FFFF"));
    paint.setColor(Color.argb(170, 0, 255, 255));
    paint.setStrokeWidth(20);
    canvas.drawLine(padX, padY, padX + padWidth, padY, paint);

    // Draw Ball
    canvas.drawCircle(ball.getX(), ball.getY(), BALL_RADIUS, paint);

    if (ball.getScore() % 200 == 0) {
        // counter = counter + 1;
        if (ball.getLevel() < MAX_LEVEL) {
            ball.setSpeedX(ball.getSpeedX() * 0.25f);
            ball.setSpeedY(ball.getSpeedY() * 0.25f);
        }
    }

    postInvalidate();

    if (ball.getY() + (float) BALL_RADIUS >= y - 6) {
        if (ball.getX() + BALL_RADIUS / 2 > padX
                && ball.getX() - BALL_RADIUS / 2 < padX + padWidth) {
            ball.setGameOver(false);
        }

        else {
            ball.setGameOver(true);
            canvas.drawText("Game Over! Please Wait.", x / 2 - 170, y / 3,
                    paint);

            Intent i = new Intent(getContext(), GameOver.class);
            i.putExtra("score", Integer.toString(ball.getScore()));
            i.putExtra("level", Integer.toString(ball.getLevel()));
            getContext().startActivity(i);
        }

    }
}

Answer 1

onDraw can be called 60 times a second, it should just draw, not handle activity flow. The minimal change is to add a boolean and make sure you call startActivity only once. A better solution is to move the activity managemen out of the drawing, and into a state management logic