Question

我有一个我在android工作室写的程序，该程序应该播放音乐笔记，并根据坐标，歌曲名称和播放笔记的时间来扩展圆形。但是，我遇到的问题是所有笔记都正确播放但是只有最后一个圈子被绘制而且我退出循环后它播放所有音符。之前我查过这个问题，并得到了一些关于调用setWillNotDraw(false);的答案，但我在构造函数中调用了这个问题，而且我仍然遇到同样的问题。我曾尝试在多个不同的地方拨打invalidate();，但似乎没有任何工作。任何帮助将不胜感激！

我的代码：

构造

public PlayView(Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);
    saver = PersistentSaver.getInstance(context);
    this.context=context;
    setWillNotDraw(false);
}

抽奖

@Override
public void onDraw(Canvas canvas){
    super.onDraw(canvas);
    this.canvas=canvas;
    if(mCurrentRect !=null&& colorPaint!=null) {
        canvas.drawOval(mCurrentRect, colorPaint);
    }
}

播放音符的循环 - 我已经检查过，所有圆坐标和音符都包含在正确的数组中：

public void playSong(){
    String song = saver.getCurrSongName();
    ArrayList<Long> Times = saver.getTimesForNotes(song);
    ArrayList<Float> xCoordinates = saver.getPressXCoordinates(song);
    ArrayList<Float> yCoordinates = saver.getPressYCoordinates(song);
    ArrayList<String> notes = saver.getNotesForSong(song);
    for(int i=0;i<Times.size();i++) {
        //pause until correct time. TODO: ADJUST ERROR BOUND
        while (true) {
            currTime = System.currentTimeMillis() - startTime;
            if (currTime <= Times.get(i) + epsilon && currTime >= Times.get(i) - epsilon) break;
        }
        //play note with that x and y coordinate and draw circle
        playNote(xCoordinates.get(i), yCoordinates.get(i), notes.get(i));
    }
}

播放音符和声音的代码：

    private void playNote(float pressx, float pressy, String note){
    colorPaint=new Paint();
    colorPaint.setStyle(Paint.Style.STROKE);
    colorPaint.setStrokeWidth(10);
    colorPaint.setColor(generateColor(pressx,pressy));
    float translateX = 50.0f;
    float translateY = 50.0f;
    Random rand = new Random(10000);
    int xr = rand.nextInt();
    int yr = rand.nextInt();
    int startColor = generateColor(pressx,pressy);
    int midColor = generateColor(pressx+rand.nextInt(),pressy+rand.nextInt());
    int endColor = generateColor(pressx+xr,pressy+yr);
    mCurrentRect = new AnimatableRectF(pressx-50,pressy-50,pressx+50,pressy+50);
    debugx=pressx;
    playAnimation(startColor,midColor,endColor, translateX, translateY);
    playSound(note);
}

假设代码播放动画但仅在循环退出后调用onDraw();

    private void playAnimation(int startColor, int midColor, int endColor, float translateX, float translateY){
    ObjectAnimator animateLeft = ObjectAnimator.ofFloat(mCurrentRect, "left", mCurrentRect.left, mCurrentRect.left-translateX);
    ObjectAnimator animateRight = ObjectAnimator.ofFloat(mCurrentRect, "right", mCurrentRect.right, mCurrentRect.right+translateX);
    ObjectAnimator animateTop = ObjectAnimator.ofFloat(mCurrentRect, "top", mCurrentRect.top, mCurrentRect.top-translateY);
    ObjectAnimator animateBottom = ObjectAnimator.ofFloat(mCurrentRect, "bottom", mCurrentRect.bottom, mCurrentRect.bottom+translateY);
    ArgbEvaluator evaluator = new ArgbEvaluator();
    ObjectAnimator animateColor = ObjectAnimator.ofObject(this, "color", evaluator, startColor,midColor,endColor);
    animateBottom.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        //TODO: DEBUG ANIMATOR
        @Override
        public void onAnimationUpdate(ValueAnimator valueAnimator) {
            postInvalidate();
        }
    });
    AnimatorSet rectAnimation = new AnimatorSet();
    rectAnimation.playTogether(animateLeft, animateRight, animateTop, animateBottom,animateColor);
    rectAnimation.setDuration(1000).start();
    invalidate();


}

playNote，playSound和generateColor方法

    //Generates color based on the press x and y.
private int generateColor(float pressx, float pressy){
    int Red = (((int) (pressx%255)) << 16) & 0x00FF0000; //Shift red 16-bits and mask out other stuff
    int Green = (((int) (pressy%255)) << 8) & 0x0000FF00; //Shift Green 8-bits and mask out other stuff
    int Blue = ((int)((pressx+pressy)%255)) & 0x000000FF; //Mask out anything not blue.

    return 0xFF000000 | Red | Green | Blue; //0xFF000000 for 100% Alpha. Bitwise OR everything together.

}

private void playSound(String noun){
    Resources res = context.getResources();
    int resID = res.getIdentifier(noun, "raw", context.getPackageName());
    MediaPlayer mediaPlayer = MediaPlayer.create(context,resID);
    mediaPlayer.start();
    mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mediaPlayer) {
            mediaPlayer.release();
        }
    });
}

private void playNote(float pressx, float pressy, String note){
    colorPaint=new Paint();
    colorPaint.setStyle(Paint.Style.STROKE);
    colorPaint.setStrokeWidth(10);
    colorPaint.setColor(generateColor(pressx,pressy));
    float translateX = 50.0f;
    float translateY = 50.0f;
    Random rand = new Random(10000);
    int xr = rand.nextInt();
    int yr = rand.nextInt();
    int startColor = generateColor(pressx,pressy);
    int midColor = generateColor(pressx+rand.nextInt(),pressy+rand.nextInt());
    int endColor = generateColor(pressx+xr,pressy+yr);
    mCurrentRect = new AnimatableRectF(pressx-50,pressy-50,pressx+50,pressy+50);
    debugx=pressx;
    playAnimation(startColor,midColor,endColor, translateX, translateY);
    playSound(note);
}

谢谢！

Answer 1

而不是使用while循环来忙碌等待播放下一个音符之前所需的时间，最好使用例如myProject.myDataset.myTable或Timer，甚至更好，使用Rx＆＃39; handler.postDelayed(runnable, delayMilliseconds)。

这是因为阻塞循环阻止UI线程运行，因此阻止了任何屏幕更新。如果您不想学习多任务处理，最简单的方法就是：

Observable.timer()

OnDraw（）仅在循环后调用一次

1 个答案: