如何将颜色在RGB格式转换为十六进制格式，反之亦然?
例如，将'#0080C0'转换为(0,128,192)。
当前回答
HEX转RGB (ES6) +测试[2022]
convertHexToRgb.ts:
/**
* RGB color regexp
*/
export const RGB_REG_EXP = /rgb\((\d{1,3}), (\d{1,3}), (\d{1,3})\)/;
/**
* HEX color regexp
*/
export const HEX_REG_EXP = /^#?(([\da-f]){3}|([\da-f]){6})$/i;
/**
* Converts HEX to RGB.
*
* Color must be only HEX string and must be:
* - 7-characters starts with "#" symbol ('#ffffff')
* - or 6-characters without "#" symbol ('ffffff')
* - or 4-characters starts with "#" symbol ('#fff')
* - or 3-characters without "#" symbol ('fff')
*
* @function { color: string => string } convertHexToRgb
* @return { string } returns RGB color string or empty string
*/
export const convertHexToRgb = (color: string): string => {
const errMessage = `
Something went wrong while working with colors...
Make sure the colors provided to the "PieDonutChart" meet the following requirements:
Color must be only HEX string and must be
7-characters starts with "#" symbol ('#ffffff')
or 6-characters without "#" symbol ('ffffff')
or 4-characters starts with "#" symbol ('#fff')
or 3-characters without "#" symbol ('fff')
- - - - - - - - -
Error in: "convertHexToRgb" function
Received value: ${color}
`;
if (
!color
|| typeof color !== 'string'
|| color.length < 3
|| color.length > 7
) {
console.error(errMessage);
return '';
}
const replacer = (...args: string[]) => {
const [
_,
r,
g,
b,
] = args;
return '' + r + r + g + g + b + b;
};
const rgbHexArr = color
?.replace(HEX_REG_EXP, replacer)
.match(/.{2}/g)
?.map(x => parseInt(x, 16));
/**
* "HEX_REG_EXP.test" is here to create more strong tests
*/
if (rgbHexArr && Array.isArray(rgbHexArr) && HEX_REG_EXP.test(color)) {
return `rgb(${rgbHexArr[0]}, ${rgbHexArr[1]}, ${rgbHexArr[2]})`;
}
console.error(errMessage);
return '';
};
我正在使用Jest进行测试
color.spec.ts
describe('function "convertHexToRgb"', () => {
it('returns a valid RGB with the provided 3-digit HEX color: [color = \'fff\']', () => {
expect.assertions(2);
const { consoleErrorMocked } = mockConsole();
const rgb = convertHexToRgb('fff');
expect(RGB_REG_EXP.test(rgb)).toBeTruthy();
expect(consoleErrorMocked).not.toHaveBeenCalled();
});
it('returns a valid RGB with the provided 3-digit HEX color with hash symbol: [color = \'#fff\']', () => {
expect.assertions(2);
const { consoleErrorMocked } = mockConsole();
const rgb = convertHexToRgb('#fff');
expect(RGB_REG_EXP.test(rgb)).toBeTruthy();
expect(consoleErrorMocked).not.toHaveBeenCalled();
});
it('returns a valid RGB with the provided 6-digit HEX color: [color = \'ffffff\']', () => {
expect.assertions(2);
const { consoleErrorMocked } = mockConsole();
const rgb = convertHexToRgb('ffffff');
expect(RGB_REG_EXP.test(rgb)).toBeTruthy();
expect(consoleErrorMocked).not.toHaveBeenCalled();
});
it('returns a valid RGB with the provided 6-digit HEX color with the hash symbol: [color = \'#ffffff\']', () => {
expect.assertions(2);
const { consoleErrorMocked } = mockConsole();
const rgb = convertHexToRgb(TEST_COLOR);
expect(RGB_REG_EXP.test(rgb)).toBeTruthy();
expect(consoleErrorMocked).not.toHaveBeenCalled();
});
it('returns an empty string when the provided value is not a string: [color = 1234]', () => {
expect.assertions(2);
const { consoleErrorMocked } = mockConsole();
// @ts-ignore
const rgb = convertHexToRgb(1234);
expect(rgb).toBe('');
expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
});
it('returns an empty string when the provided color is too short: [color = \'FF\']', () => {
expect.assertions(2);
const { consoleErrorMocked } = mockConsole();
const rgb = convertHexToRgb('FF');
expect(rgb).toBe('');
expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
});
it('returns an empty string when the provided color is too long: [color = \'#fffffff\']', () => {
expect.assertions(2);
const { consoleErrorMocked } = mockConsole();
const rgb = convertHexToRgb('#fffffff');
expect(rgb).toBe('');
expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
});
it('returns an empty string when the provided value is looks like HEX color string but has invalid symbols: [color = \'#fffffp\']', () => {
expect.assertions(2);
const { consoleErrorMocked } = mockConsole();
const rgb = convertHexToRgb('#fffffp');
expect(rgb).toBe('');
expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
});
it('returns an empty string when the provided value is invalid: [color = \'*\']', () => {
expect.assertions(2);
const { consoleErrorMocked } = mockConsole();
const rgb = convertHexToRgb('*');
expect(rgb).toBe('');
expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
});
it('returns an empty string when the provided value is undefined: [color = undefined]', () => {
expect.assertions(2);
const { consoleErrorMocked } = mockConsole();
// @ts-ignore
const rgb = convertHexToRgb(undefined);
expect(rgb).toBe('');
expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
});
});
测试结果:
function "convertHexToRgb"
√ returns a valid RGB with the provided 3-digit HEX color: [color = 'fff']
√ returns a valid RGB with the provided 3-digit HEX color with hash symbol: [color = '#fff']
√ returns a valid RGB with the provided 6-digit HEX color: [color = 'ffffff']
√ returns a valid RGB with the provided 6-digit HEX color with the hash symbol: [color = '#ffffff']
√ returns an empty string when the provided value is not a string: [color = 1234]
√ returns an empty string when the provided color is too short: [color = 'FF']
√ returns an empty string when the provided color is too long: [color = '#fffffff']
√ returns an empty string when the provided value is looks like HEX color string but has invalid symbols: [color = '#fffffp']
√ returns an empty string when the provided value is invalid: [color = '*']
√ returns an empty string when the provided value is undefined: [color = undefined]
和mockConsole:
export const mockConsole = () => {
const consoleError = jest.spyOn(console, 'error').mockImplementationOnce(() => undefined);
return { consoleError };
};
其他回答
看起来你在寻找这样的东西:
function hexstr(number) {
var chars = new Array("0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f");
var low = number & 0xf;
var high = (number >> 4) & 0xf;
return "" + chars[high] + chars[low];
}
function rgb2hex(r, g, b) {
return "#" + hexstr(r) + hexstr(g) + hexstr(b);
}
Tim Down给出的最高评级的答案提供了我所能看到的转换为RGB的最佳解决方案。我更喜欢这个十六进制转换的解决方案，因为它为转换到十六进制提供了最简洁的边界检查和零填充。
function RGBtoHex (red, green, blue) {
red = Math.max(0, Math.min(~~red, 255));
green = Math.max(0, Math.min(~~green, 255));
blue = Math.max(0, Math.min(~~blue, 255));
return '#' + ('00000' + (red << 16 | green << 8 | blue).toString(16)).slice(-6);
};
左移'<<'和或'|'操作符的使用也使这成为一个有趣的解决方案。
哇。这些答案都不能处理分数的边缘情况，等等。当r, g, b为零时，位移版本也不起作用。
这是一个可以处理r g b是小数的版本。它对颜色之间的插值很有用，所以我也包括了这段代码。但它仍然不能处理r, g, b在0-255范围之外的情况
/**
* Operates with colors.
* @class Q.Colors
*/
Q.Color = {
/**
* Get a color somewhere between startColor and endColor
* @method toHex
* @static
* @param {String|Number} startColor
* @param {String|Number} endColor
* @param {String|Number} fraction
* @returns {String} a color as a hex string without '#' in front
*/
toHex: function (r, g, b) {
return [r, g, b].map(x => {
const hex = Math.round(x).toString(16)
return hex.length === 1 ? '0' + hex : hex
}).join('');
},
/**
* Get a color somewhere between startColor and endColor
* @method between
* @static
* @param {String|Number} startColor
* @param {String|Number} endColor
* @param {String|Number} fraction
* @returns {String} a color as a hex string without '#' in front
*/
between: function(startColor, endColor, fraction) {
if (typeof startColor === 'string') {
startColor = parseInt(startColor.replace('#', '0x'), 16);
}
if (typeof endColor === 'string') {
endColor = parseInt(endColor.replace('#', '0x'), 16);
}
var startRed = (startColor >> 16) & 0xFF;
var startGreen = (startColor >> 8) & 0xFF;
var startBlue = startColor & 0xFF;
var endRed = (endColor >> 16) & 0xFF;
var endGreen = (endColor >> 8) & 0xFF;
var endBlue = endColor & 0xFF;
var newRed = startRed + fraction * (endRed - startRed);
var newGreen = startGreen + fraction * (endGreen - startGreen);
var newBlue = startBlue + fraction * (endBlue - startBlue);
return Q.Color.toHex(newRed, newGreen, newBlue);
},
/**
* Sets a new theme-color on the window
* @method setWindowTheme
* @static
* @param {String} color in any CSS format, such as "#aabbcc"
* @return {String} the previous color
*/
setWindowTheme: function (color) {
var meta = document.querySelector('meta[name="theme-color"]');
var prevColor = null;
if (meta) {
prevColor = meta.getAttribute('content');
}
if (color) {
if (!meta) {
meta = document.createElement('meta');
meta.setAttribute('name', 'theme-color');
}
meta.setAttribute('content', color);
}
return prevColor;
},
/**
* Gets the current window theme color
* @method getWindowTheme
* @static
* @param {String} color in any CSS format, such as "#aabbcc"
* @return {String} the previous color
*/
getWindowTheme: function () {
var meta = document.querySelector('meta[name="theme-color"]');
return meta.getAttribute('content');
}
}
当你在3D环境中工作时(webGL, ThreeJS)，你有时需要为网格的不同面创建3个值，基本的一个(主色)，一个浅一点的和一个深一点的:
material.color.set( 0x660000, 0xff0000, 0xff6666 ); // red cube
我们可以从主RBG颜色创建这3个值:255,0,0
function rgbToHex(rgb) {
var hex = Number(rgb).toString(16);
if (hex.length < 2) {
hex = "0" + hex;
}
return hex;
};
function convertToHex(r,g,b) {
var fact = 100; // contrast
var code = '0x';
// main color
var r_hexa = rgbToHex(r);
var g_hexa = rgbToHex(g);
var b_hexa = rgbToHex(b);
// lighter
var r_light = rgbToHex(Math.floor(r+((1-(r/255))*fact)));
var g_light = rgbToHex(Math.floor(g+((1-(g/255))*fact)));
var b_light = rgbToHex(Math.floor(b+((1-(b/255))*fact)));
// darker
var r_dark = rgbToHex(Math.floor(r-((r/255)*(fact*1.5)))); // increase contrast
var g_dark = rgbToHex(Math.floor(g-((g/255)*(fact*1.5))));
var b_dark = rgbToHex(Math.floor(b-((b/255)*(fact*1.5))));
var hexa = code+r_hexa+g_hexa+b_hexa;
var light = code+r_light+g_light+b_light;
var dark = code+r_dark+g_dark+b_dark;
console.log('HEXs -> '+dark+" + "+hexa+" + "+light)
var colors = [dark, hexa, light];
return colors;
}
在你的ThreeJS代码中简单地写:
var material = new THREE.MeshLambertMaterial();
var c = convertToHex(255,0,0); // red cube needed
material.color.set( Number(c[0]), Number(c[1]), Number(c[2]) );
结果:
// dark normal light
convertToHex(255,255,255) HEXs -> 0x696969 + 0xffffff + 0xffffff
convertToHex(255,0,0) HEXs -> 0x690000 + 0xff0000 + 0xff6464
convertToHex(255,127,0) HEXs -> 0x690000 + 0xff0000 + 0xff6464
convertToHex(100,100,100) HEXs -> 0x292929 + 0x646464 + 0xa0a0a0
convertToHex(10,10,10) HEXs -> 0x040404 + 0x0a0a0a + 0x6a6a6a
ECMAScript 6版本的Tim Down的答案
将RGB转换为十六进制
const rgbToHex = (r, g, b) => '#' + [r, g, b]。映射(x => { const十六进制= x.toString(16) 返回十六进制。长度=== 1 ?'0' + hex: hex }) . join () console.log(rgbToHex(0,51,255));/ / # 0033 ff的
将十六进制转换为RGB
返回一个数组[r, g, b]。工作也与速记十六进制三胞胎，如“#03F”。
const hexToRgb = hex => hex.replace (/ ^ # ? (\ d] [a - f) (\ d] [a - f) (\ d] [a - f) $ /我 ，(m, r, g, b) => '#' + r + r + g + g + b + b) .substring (1) .match (/ {2} / g)。 .map(x => parseInt(x, 16)) console.log(hexToRgb("#0033ff")) // [0,51,255] console.log(hexToRgb("#03f")) // [0,51,255]
附加:RGB到十六进制使用padStart()方法
const rgbToHex = (r, g, b) => '#' + [r, g, b] .map(x => x. tostring(16)。padStart (2, ' 0 ')) . join () console.log(rgbToHex(0,51,255));/ / # 0033 ff的
注意，这个答案使用了最新的ECMAScript特性，旧的浏览器不支持这些特性。如果希望此代码在所有环境中都能工作，则应该使用Babel来编译代码。
