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)。
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
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);
}
其他回答
我假设您指的是html风格的十六进制符号,即#rrggbb。你的代码几乎是正确的,只是顺序颠倒了。它应该是:
var decColor = red * 65536 + green * 256 + blue;
此外,使用位移位可能会让它更容易阅读:
var decColor = (red << 16) + (green << 8) + blue;
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 };
};
你想要这样的东西吗?
function RGB2HTML(red, green, blue)
{
return '#' + red.toString(16) +
green.toString(16) +
blue.toString(16);
}
alert(RGB2HTML(150, 135, 200));
显示# 9687 c8
我正在使用XAML数据,具有十六进制格式的#AARRGGBB (Alpha,红色,绿色,蓝色)。利用上面的答案,以下是我的解决方案:
function hexToRgba(hex) {
var bigint, r, g, b, a;
//Remove # character
var re = /^#?/;
var aRgb = hex.replace(re, '');
bigint = parseInt(aRgb, 16);
//If in #FFF format
if (aRgb.length == 3) {
r = (bigint >> 4) & 255;
g = (bigint >> 2) & 255;
b = bigint & 255;
return "rgba(" + r + "," + g + "," + b + ",1)";
}
//If in #RRGGBB format
if (aRgb.length >= 6) {
r = (bigint >> 16) & 255;
g = (bigint >> 8) & 255;
b = bigint & 255;
var rgb = r + "," + g + "," + b;
//If in #AARRBBGG format
if (aRgb.length == 8) {
a = ((bigint >> 24) & 255) / 255;
return "rgba(" + rgb + "," + a.toFixed(1) + ")";
}
}
return "rgba(" + rgb + ",1)";
}
http://jsfiddle.net/kvLyscs3/
这可以用于从计算样式属性中获取颜色:
function rgbToHex(color) {
color = ""+ color;
if (!color || color.indexOf("rgb") < 0) {
return;
}
if (color.charAt(0) == "#") {
return color;
}
var nums = /(.*?)rgb\((\d+),\s*(\d+),\s*(\d+)\)/i.exec(color),
r = parseInt(nums[2], 10).toString(16),
g = parseInt(nums[3], 10).toString(16),
b = parseInt(nums[4], 10).toString(16);
return "#"+ (
(r.length == 1 ? "0"+ r : r) +
(g.length == 1 ? "0"+ g : g) +
(b.length == 1 ? "0"+ b : b)
);
}
// not computed
<div style="color: #4d93bc; border: 1px solid red;">...</div>
// computed
<div style="color: rgb(77, 147, 188); border: 1px solid rgb(255, 0, 0);">...</div>
console.log( rgbToHex(color) ) // #4d93bc
console.log( rgbToHex(borderTopColor) ) // #ff0000
裁判:https://github.com/k-gun/so/blob/master/so_util.js