十六进制代码中的每个不透明值

/**
     * 此方法计算十六进制代码中的每个不透明值
     * @param args
     */
    public static void main(String[] args) {
        for (double i = 1; i >= 0; i -= 0.01) {
            i = Math.round(i * 100) / 100.0d;
            int alpha = (int) Math.round(i * 255);
            String hex = Integer.toHexString(alpha).toUpperCase();
            if (hex.length() == 1) hex = "0" + hex;
            int percent = (int) (i * 100);
            System.out.printf("%d%% — %s%n", percent, hex);
        }
    }
    100% — FF
	99% — FC
	98% — FA
	97% — F7
	96% — F5
	95% — F2
	94% — F0
	93% — ED
	92% — EB
	91% — E8
	90% — E6
	89% — E3
	88% — E0
	87% — DE
	86% — DB
	85% — D9
	84% — D6
	83% — D4
	82% — D1
	81% — CF
	80% — CC
	79% — C9
	78% — C7
	77% — C4
	76% — C2
	75% — BF
	74% — BD
	73% — BA
	72% — B8
	71% — B5
	70% — B3
	69% — B0
	68% — AD
	67% — AB
	66% — A8
	65% — A6
	64% — A3
	63% — A1
	62% — 9E
	61% — 9C
	60% — 99
	59% — 96
	57% — 94
	56% — 91
	56% — 8F
	55% — 8C
	54% — 8A
	53% — 87
	52% — 85
	51% — 82
	50% — 80
	49% — 7D
	48% — 7A
	47% — 78
	46% — 75
	45% — 73
	44% — 70
	43% — 6E
	42% — 6B
	41% — 69
	40% — 66
	39% — 63
	38% — 61
	37% — 5E
	36% — 5C
	35% — 59
	34% — 57
	33% — 54
	32% — 52
	31% — 4F
	30% — 4D
	28% — 4A
	28% — 47
	27% — 45
	26% — 42
	25% — 40
	24% — 3D
	23% — 3B
	22% — 38
	21% — 36
	20% — 33
	19% — 30
	18% — 2E
	17% — 2B
	16% — 29
	15% — 26
	14% — 24
	13% — 21
	12% — 1F
	11% — 1C
	10% — 1A
	9% — 17
	8% — 14
	7% — 12
	6% — 0F
	5% — 0D
	4% — 0A
	3% — 08
	2% — 05
	1% — 03
	0% — 00
	
	参考：[如何在XML绘图上将alpha/不透明值设置为颜色？]
	(https://stackoverflow.com/questions/16611759/how-set-alpha-opacity-value-to-color-on-xml-drawable)