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

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);
}

建立了我自己的十六进制RGB转换器。我希望这能帮助到一些人。

我用react来做沙盒。

用法:

根据官方文档安装React，或者如果你全局安装了npx，运行npx create-react-app hexto -rgb

import React, { Component, Fragment } from 'react';
const styles = {
  display: 'block',
  margin: '20px auto',
  input: {
    width: 170,
  },
  button: {
    margin: '0 auto'
  }
}

//  test case 1
//    #f0f
//  test case 2
//    #ff00ff

class HexToRGBColorConverter extends Component {

  state = {
    result: false,
    color: "#ff00ff",
  }
  
  hexToRgb = color => {    
    let container = [[], [], []];
    // check for shorthand hax string
    if (color.length >= 3) {
      // remove hash from string
      // convert string to array
      color = color.substring(1).split("");
      for (let key = 0; key < color.length; key++) {        
        let value = color[key];
        container[2].push(value);
        // if the length is 3 we 
        // we need to add the value 
        // to the index we just updated
        if (color.length === 3) container[2][key] += value;
      }
      
      for (let index = 0; index < color.length; index++) {
        let isEven = index % 2 === 0;
        // If index is odd an number 
        // push the value into the first
        // index in our container
        if (isEven) container[0].push(color[index]);
        // If index is even an number 
        if (!isEven) {
          // again, push the value into the
          // first index in the container
          container[0] += color[index];
          // Push the containers first index
          // into the second index of the container
          container[1].push(container[0]);
          // Flush the first index of
          // of the container 
          // before starting a new set
          container[0] = [];
        }
      }
      // Check container length
      if (container.length === 3) {
        // Remove only one element of the array
        // Starting at the array's first index
        container.splice(0, 1);
        let values = container[color.length % 2];
        return {
          r: parseInt(values[0], 16),
          g: parseInt(values[1], 16),
          b: parseInt(values[2], 16)
        }
      }
    }
    return false;
  }  

  handleOnClick = event => {
    event.preventDefault();
    const { color } = this.state;
    const state = Object.assign({}, this.state);
    state.result = this.hexToRgb(color);
    this.setState(state);
  }

  handleOnChange = event => {
    event.preventDefault();
    const { value } = event.currentTarget;
    const pattern = /^([a-zA-Z0-9])/;
    const boundaries = [3, 6];
    if (
      pattern.test(value) &&
      boundaries.includes(value.length)
    ) {
      const state = Object.assign({}, this.state);
      state.color = `#${value}`;
      this.setState(state);
    }
  }

  render() {
    const { color, result } = this.state;
    console.log('this.state ', color, result);

    return (
      <Fragment>
        <input 
          type="text" 
          onChange={this.handleOnChange} 
          style={{ ...styles, ...styles.input }} />
        <button 
          onClick={this.handleOnClick}
          style={{ ...styles, ...styles.button }}>
          Convert hex to rgba
        </button>
        { 
          !!result && 
          <div style={{ textAlign: 'center' }}>
            Converted { color } to { JSON.stringify(result) }
          </div> 
        }
      </Fragment>
    )
  }
}
export default App;

快乐编码=)

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

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);

我的hex2rbg版本:

接受短十六进制，如#fff 算法容量为o(n)，应该比使用正则表达式快。如字符串。替换字符串。分裂,字符串。匹配等。 使用固定空间。 支持rgb和rgba。

如果你使用的是IE8，你可能需要删除hex.trim()。

如。

hex2rgb('#fff') //rgb(255,255,255) 
hex2rgb('#fff', 1) //rgba(255,255,255,1) 
hex2rgb('#ffffff') //rgb(255,255,255)  
hex2rgb('#ffffff', 1) //rgba(255,255,255,1)

代码:

function hex2rgb (hex, opacity) {
    hex = hex.trim();
    hex = hex[0] === '#' ? hex.substr(1) : hex;
    var bigint = parseInt(hex, 16), h = [];
    if (hex.length === 3) {
        h.push((bigint >> 4) & 255);
        h.push((bigint >> 2) & 255);
    } else {
        h.push((bigint >> 16) & 255);
        h.push((bigint >> 8) & 255);
    }
    h.push(bigint & 255);
    if (arguments.length === 2) {
        h.push(opacity);
        return 'rgba('+h.join()+')';
    } else {
        return 'rgb('+h.join()+')';
    }
}