Android 一个带圆角的弧形

public class TestView extends View {    RectF outRectF = new RectF();    RectF innRectF = new RectF();    Paint paint;    Paint paint2;    private Paint mTrackColor = new Paint();    Path path;    public TestView(Context context) {        this(context, null);    }    public TestView(Context context, @Nullable AttributeSet attrs) {        this(context, attrs, 0);    }    public TestView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        outRectF.left = 30;        outRectF.right = 630;        outRectF.top = 30;        outRectF.bottom = 630;        innRectF.left = 180;        innRectF.right = 480;        innRectF.top = 180;        innRectF.bottom = 480;        paint = new Paint();        paint.setAntiAlias(true);        paint.setColor(Color.BLACK);        paint.setStyle(Paint.Style.STROKE);        paint2 = new Paint();        paint2.setAntiAlias(true);        paint2.setColor(Color.BLACK);        paint2.setStyle(Paint.Style.STROKE);        paint2.setStrokeWidth(60);        paint2.setStrokeCap(Paint.Cap.ROUND);        MaskFilter mEmboss = new EmbossMaskFilter(new float[] { 0.0f, -1.0f, 0.5f},                0.8f, 15, 1.0f);        mTrackColor.setMaskFilter(mEmboss);        mTrackColor.setColor(0xffff9800);        path = new Path();    }    @Override    protected void onFinishInflate() {        super.onFinishInflate();    }    int circleX = 800;    int circleY = 1200;    int r = 600;    int d = 250;    int round = 15;    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        canvas.drawCircle(circleX, circleY, r, paint);        drawArc(canvas, -90, 90f/4f, mTrackColor);//        canvas.drawArc(outRectF, 180, 40, false, paint2);    }    private void drawArc(Canvas canvas, float startAngle, float sweepAngle, Paint paint) {        path.reset();        // 计算圆角占得角度        float angle1 = (float) (Math.sinh(((double) round / 2) / (double) (r - round)) * 2 * 180 / Math.PI);        float angle2 = (float) (Math.sinh(((double) round / 2) / (double) (r - d + round)) * 2 * 180 / Math.PI);        // 四个圆角的圆心        float[] startPoint = calculatePointOnArc(circleX, circleY, r - round, startAngle + angle1);        float[] endPoint = calculatePointOnArc(circleX, circleY, r - round, startAngle + sweepAngle - angle1);        float[] startPoint2 = calculatePointOnArc(circleX, circleY, r - d + round, startAngle + angle2);        float[] endPoint2 = calculatePointOnArc(circleX, circleY, r - d + round, startAngle + sweepAngle - angle2);        // 画左右边界        outRectF = getRectF(circleX, circleY, r - round);        innRectF = getRectF(circleX, circleY, r - d + round);        path.arcTo(outRectF, startAngle, sweepAngle);        path.arcTo(innRectF, startAngle + sweepAngle, -sweepAngle);        path.close();        outRectF = getRectF(circleX, circleY, r);        innRectF = getRectF(circleX, circleY, r - d);        // 画上下圆弧        path.arcTo(outRectF, startAngle + angle1, sweepAngle - angle1 * 2);        path.arcTo(innRectF, startAngle + sweepAngle - angle2, -sweepAngle + angle2 * 2);        // drawing the circle at both the end point of the arc to git it rounded look.        path.addCircle(startPoint[0], startPoint[1], round, Path.Direction.CW);        path.addCircle(endPoint[0], endPoint[1], round, Path.Direction.CW);        path.addCircle(endPoint2[0], endPoint2[1], round, Path.Direction.CW);        path.addCircle(startPoint2[0], startPoint2[1], round, Path.Direction.CW);        path.close();        canvas.drawPath(path, paint);    }    RectF getRectF(int circleX, int circleY, int r) {        RectF rectF = new RectF();        rectF.left = circleX - r;        rectF.right = circleX + r;        rectF.top = circleY - r;        rectF.bottom = circleY + r;        return rectF;    }    // this is to calculate the end points of the arc    private float[] calculatePointOnArc(int circleCeX, int circleCeY, int circleRadius, float endAngle)    {        float[] point = new float[2];        double endAngleRadian = endAngle * (Math.PI / 180);        double pointX = Math.round((circleCeX + circleRadius * Math.cos(endAngleRadian)));        double pointY = Math.round((circleCeY + circleRadius * Math.sin(endAngleRadian)));        point[0] = (float) pointX;        point[1] = (float) pointY;        return point;    }}