package com.version2;

/**
 * @author xu
 * @create 2019-07-12 7:55
 */
/**
 * 将rgb值装换为16进制值，
 * 将16进制转为rgb
 */
public class ColorToHex {

    public static String toHex(int r, int g, int b) {
        return "#" + toBrowserHexValue(r) + toBrowserHexValue(g)
                + toBrowserHexValue(b);
    }

    private static String toBrowserHexValue(int rgb) {
        StringBuilder sb = new StringBuilder(
                Integer.toHexString(rgb & 0xff));
        //为什么要和0xff做&运算？保持二进制补码的一致性
        while (sb.length() < 2) {
            sb.append("0");
        }
        return sb.toString().toUpperCase();
    }

    public static String toInt(String hex){
        //要头不要尾
        String r = rgbToNumber(hex.substring(0,2));
        String g = rgbToNumber(hex.substring(2,4));
        String b = rgbToNumber(hex.substring(4,6));

        return "["+r+","+g+","+b+"]";
    }
    private static String rgbToNumber(String str){
        return ""+Integer.parseUnsignedInt(str,16);
    }

    public static void main(String[] args) {
        System.out.println(toHex(255, 0, 0));
        System.out.println(Integer.parseUnsignedInt("a8",16));
    }
}