NLockView.java 文件源码

private void clearCanvas(Canvas canvas, Point p) {
    // 将点下面的线清除(前提是父容器必须有设置背景)
    Xfermode xfermode = mPaint.getXfermode();
    int color = mPaint.getColor();
    mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
    mPaint.setColor(Color.TRANSPARENT);
    canvas.drawCircle(p.x, p.y, mRadius, mPaint);
    mPaint.setXfermode(xfermode);
    mPaint.setColor(color);
}