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我真正想要的是一个弧线移动的效果看起来像流星从天而降的动画，你可以在LG G3的圆形外壳小窗口上看到动画，每次关闭外壳时，动画都会在环周围发光，查看此视频，来自 youtube（您可以在 00:18、00:30、01:18、01:29 ... 看到它）：

https://www.youtube.com/watch?v=tEQpYms1bJA

我做了一点搜索，并编写了我的代码（参考this），但是绘制弧线的线条看起来很实心，没有我想要的效果，这是我的弧线绘制代码：

public class SideArcsView extends View{

private Paint mPaint;
private int parentWidth;
private int strokeWidth;
private RectF oval;
private static int INITIAL_LEFT_ARC_START_ANGLE = 225;
private static int INITIAL_RIGHT_ARC_START_ANGLE = 315;
private int startLeftArcAngle = INITIAL_LEFT_ARC_START_ANGLE;
private int startRightArcAngle = INITIAL_RIGHT_ARC_START_ANGLE;
private int arcAngle = 45;

public SideArcsView(Context mContext, int parentWidth) {
    super(mContext);
    this.parentWidth = parentWidth;
    init();
}

private void init() {
    strokeWidth = (12 * parentWidth) / 300;
    initPaint();
    initOval();
}

private void initPaint() {
    mPaint = new Paint();
    mPaint.setColor(Color.WHITE);
    mPaint.setStrokeWidth(strokeWidth);
    mPaint.setStyle(Paint.Style.STROKE);
    mPaint.setAntiAlias(true);
    mPaint.setStrokeCap(Paint.Cap.ROUND);
}

private void initOval() {
    float padding = mPaint.getStrokeWidth() / 2;
    oval = new RectF();
    oval.set(padding, padding, parentWidth - padding, parentWidth - padding);
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    drawArcs(canvas);
}

private void drawArcs(Canvas canvas) {
    canvas.drawArc(oval, startLeftArcAngle, arcAngle, false, mPaint);
    canvas.drawArc(oval, startRightArcAngle, -arcAngle, false, mPaint);
}

public void startRotateAnimation() {
    ValueAnimator valueAnimator = ValueAnimator.ofInt(0, 136);
    valueAnimator.setInterpolator(new DecelerateInterpolator());
    valueAnimator.setDuration(2000);
    valueAnimator.setRepeatCount(ValueAnimator.INFINITE);
    valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
            startLeftArcAngle = INITIAL_LEFT_ARC_START_ANGLE - (int) animation.getAnimatedValue();
            startRightArcAngle = INITIAL_RIGHT_ARC_START_ANGLE + (int) animation.getAnimatedValue();
            invalidate();
        }
    });
    valueAnimator.start();
}

public void startResizeDownAnimation() {
    ValueAnimator valueAnimator = ValueAnimator.ofInt(45, 10);
    valueAnimator.setInterpolator(new DecelerateInterpolator());
    valueAnimator.setDuration(2000);
    valueAnimator.setRepeatCount(ValueAnimator.INFINITE);
    valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
            arcAngle = (int) animation.getAnimatedValue();
            invalidate();
        }
    });
    valueAnimator.start();
}

}

它看起来像：

在此处输入图像描述

有人能告诉我如何画出像 LG G3 的发光圆环这样的东西吗？请给我一些建议...

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