给定这个函数,我想用随机颜色生成器替换颜色。

document.overlay = GPolyline.fromEncoded({
    color: "#0000FF",
    weight: 10,
    points: encoded_points,
    zoomFactor: 32,
    levels: encoded_levels,
    numLevels: 4
});

我该怎么做呢?


当前回答

增强了一点的一行代码,使方法更加生动

'#' + Math.round((0x1000000 + 0xffffff * Math.random())).toString(16).slice(1)

其他回答

另一个随机颜色生成器:

var randomColor;
randomColor = Math.random() * 0x1000000; // 0 < randomColor < 0x1000000 (randomColor is a float)
randomColor = Math.floor(randomColor); // 0 < randomColor <= 0xFFFFFF (randomColor is an integer)
randomColor = randomColor.toString(16); // hex representation randomColor
randomColor = ("000000" + randomColor).slice(-6); // leading zeros added
randomColor = "#" + randomColor; // # added

有多种方法来创建随机十六进制颜色代码在博客文章中随机十六进制颜色代码生成器在JavaScript。当随机值小于0×100000时,你需要用0填充,所以下面是正确的版本:

var randomColor = "#000000".replace(/0/g,function(){return (~~(Math.random()*16)).toString(16);});

这将用一个随机的十六进制数字替换六个0中的每一个,因此它一定会得到一个完整的六位数有效颜色值。

投票最多的回答表明,Martin Ankerl的方法比随机十六进制数字更好,尽管我还没有改进Ankerl的方法,但我已经成功地将其翻译成JavaScript。

我想我应该对这个已经非常大的Stack Overflow问题发布一个额外的答案,因为顶部的答案有另一个评论链接到一个带有Ankerl逻辑的JavaScript实现的Gist,而这个链接是坏的(404)。如果我有这样的声誉,我就会简单地注释我创建的jsbin链接。

// Adapted from
// http://jsfiddle.net/Mottie/xcqpF/1/light/
const rgb2hex = (rgb) => {
  return (rgb && rgb.length === 3) ? "#" +
    ("0" + parseInt(rgb[0],10).toString(16)).slice(-2) +
    ("0" + parseInt(rgb[1],10).toString(16)).slice(-2) +
    ("0" + parseInt(rgb[2],10).toString(16)).slice(-2) : '';
}

// The next two methods are converted from Ruby to JavaScript.
// It is sourced from http://martin.ankerl.com/2009/12/09/how-to-create-random-colors-programmatically/

// # HSV values in [0..1[
// # returns [r, g, b] values from 0 to 255
const hsv_to_rgb = (h, s, v) => {
  const h_i = Math.floor(h*6)
  const f = h*6 - h_i
  const p = v * (1 - s)
  const q = v * (1 - (f * s))
  const t = v * (1 - (1 - f) * s)
  let r, g, b
  switch(h_i) {
    case(0):
      [r, g, b] = [v, t, p]
      break
    case(1):
      [r, g, b] = [q, v, p]
      break
    case(2):
      [r, g, b] = [p, v, t]
      break
    case(3):
      [r, g, b] = [p, q, v]
      break
    case(4):
      [r, g, b] = [t, p, v]
      break
    case(5):
      [r, g, b] = [v, p, q]
      break
  }
  return [Math.floor(r * 256), Math.floor(g * 256), Math.floor(b * 256)]
}

// # Use the golden ratio
const golden_ratio_conjugate = 0.618033988749895
let h = Math.random() // # Use a random start value
const gen_hex = (numberOfColors) => {
  const colorArray = []
  while (numberOfColors > 0) {
    h += golden_ratio_conjugate
    h %= 1
    colorArray.push(rgb2hex(hsv_to_rgb(h, 0.99, 0.99)))
    numberOfColors -= 1
  }
  console.log(colorArray)
  return colorArray
}

gen_hex(100)

https://jsbin.com/qeyevoj/edit?js,console

使用getRandomColor()代替“#0000FF”:

function getRandomColor() { var letters = '0123456789ABCDEF'; var color = '#'; for (var i = 0; i < 6; i++) { color += letters[Math.floor(Math.random() * 16)]; } return color; } function setRandomColor() { $("#colorpad").css("background-color", getRandomColor()); } <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div id="colorpad" style="width:300px;height:300px;background-color:#000"> </div> <button onclick="setRandomColor()">Random Color</button>

function getRandomColor()
{
    var color = "#";

    for (var i = 0; i < 3; i++)
    {
        var part = Math.round(Math.random() * 255).toString(16);

        color += (part.length > 1) ? part : "0" + part;
    }

    return color;
}