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

如果你像我一样是个新手,对十六进制之类的东西一无所知,这可能更直观。

function r() {
  return Math.floor(Math.random() * 256);
}

const color = "rgb(" + r() + "," + r() + "," + r() + ")";

你只需要以一个字符串结束,比如“rgb(255, 123, 220)”。

其他回答

Use:

function random_color(format)
{
    var rint = Math.round(0xffffff * Math.random());
    switch(format)
    {
        case 'hex':
            return ('#0' + rint.toString(16)).replace(/^#0([0-9a-f]{6})$/i, '#$1');
            break;

        case 'rgb':
            return 'rgb(' + (rint >> 16) + ',' + (rint >> 8 & 255) + ',' + (rint & 255) + ')';
            break;

        default:
            return rint;
            break;
    }
}

升级版:

function random_color( format ){
  var rint = Math.floor( 0x100000000 * Math.random());
  switch( format ){
    case 'hex':
      return '#' + ('00000'   + rint.toString(16)).slice(-6).toUpperCase();
    case 'hexa':
      return '#' + ('0000000' + rint.toString(16)).slice(-8).toUpperCase();
    case 'rgb':
      return 'rgb('  + (rint & 255) + ',' + (rint >> 8 & 255) + ',' + (rint >> 16 & 255) + ')';
    case 'rgba':
      return 'rgba(' + (rint & 255) + ',' + (rint >> 8 & 255) + ',' + (rint >> 16 & 255) + ',' + (rint >> 24 & 255)/255 + ')';
    default:
      return rint;
  }
}

我喜欢这个:'#' + (Math.random().toString(16) + "000000").substring(2,8)

我认为第一个回答是最简洁/有用的,但我只是写了一个初学者可能更容易理解的回答。

function randomHexColor(){
    var hexColor=[]; //new Array()
    hexColor[0] = "#"; //first value of array needs to be hash tag for hex color val, could also prepend this later

    for (i = 1; i < 7; i++)
    {
        var x = Math.floor((Math.random()*16)); //Tricky: Hex has 16 numbers, but 0 is one of them

        if (x >=10 && x <= 15) //hex:0123456789ABCDEF, this takes care of last 6 
        {
            switch(x)
            {
                case 10: x="a" 
                break;
                case 11: x="b" 
                break;
                case 12: x="c" 
                break;
                case 13: x="d" 
                break;
                case 14: x="e" 
                break;
                case 15: x="f" 
                break;  
            }
        }
        hexColor[i] = x;
    }
    var cString = hexColor.join(""); //this argument for join method ensures there will be no separation with a comma
    return cString;
}

您还可以使用在所有优秀浏览器(http://caniuse.com/#feat=css3-colors)上可用的HSL。

function randomHsl() {
    return 'hsla(' + (Math.random() * 360) + ', 100%, 50%, 1)';
}

这将给你只有明亮的颜色,你可以玩亮度,饱和度和阿尔法。

// es6
const randomHsl = () => `hsla(${Math.random() * 360}, 100%, 50%, 1)`

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>