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
如果你需要比较两个颜色值(给定为RGB，名称颜色或十六进制值)或转换为hex使用HTML5 canvas对象。
var canvas = document.createElement("canvas");
var ctx = this.canvas.getContext('2d');
ctx.fillStyle = "rgb(pass,some,value)";
var temp = ctx.fillStyle;
ctx.fillStyle = "someColor";
alert(ctx.fillStyle == temp);
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 };
};
//忽略hsl符号，颜色值通常表示为名称，rgb, rgba或十六进制
//十六进制可以是3或6。
// Rgb可以是百分比也可以是整数值。
//至少最好能解释所有这些格式。
String.prototype.padZero= function(len, c){
var s= this, c= c || "0", len= len || 2;
while(s.length < len) s= c + s;
return s;
}
var colors={
colornames:{
aqua: '#00ffff', black: '#000000', blue: '#0000ff', fuchsia: '#ff00ff',
gray: '#808080', green: '#008000', lime: '#00ff00', maroon: '#800000',
navy: '#000080', olive: '#808000', purple: '#800080', red: '#ff0000',
silver: '#c0c0c0', teal: '#008080', white: '#ffffff', yellow: '#ffff00'
},
toRgb: function(c){
c= '0x'+colors.toHex(c).substring(1);
c= [(c>> 16)&255, (c>> 8)&255, c&255];
return 'rgb('+c.join(',')+')';
},
toHex: function(c){
var tem, i= 0, c= c? c.toString().toLowerCase(): '';
if(/^#[a-f0-9]{3,6}$/.test(c)){
if(c.length< 7){
var A= c.split('');
c= A[0]+A[1]+A[1]+A[2]+A[2]+A[3]+A[3];
}
return c;
}
if(/^[a-z]+$/.test(c)){
return colors.colornames[c] || '';
}
c= c.match(/\d+(\.\d+)?%?/g) || [];
if(c.length<3) return '';
c= c.slice(0, 3);
while(i< 3){
tem= c[i];
if(tem.indexOf('%')!= -1){
tem= Math.round(parseFloat(tem)*2.55);
}
else tem= parseInt(tem);
if(tem< 0 || tem> 255) c.length= 0;
else c[i++]= tem.toString(16).padZero(2);
}
if(c.length== 3) return '#'+c.join('').toLowerCase();
return '';
}
}
//var c='#dc149c';
//var c='rgb(100%,25%,0)';
//
var c= 'red';
alert(colors.toRgb(c)+'\n'+colors.toHex(c));
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。
如果这有助于任何人，我的API有这些转换的函数。
<script src="http://api.xlww.net/xQuery/xQuery.js"></script>
<script>
x.init();
var rgb=new x.rgb(37,255,83);
alert(rgb.hex);
var hex=new x.hex("#ffa500");
alert("("+hex.rgb[0]+","+hex.rgb[1]+","+hex.rgb[2]+")");
</script>
