使用HTML5技术开发的超酷颜色选择器

<!-- preview element --><p class="preview"></p><!-- colorpicker element --><p class="colorpicker" style="display:none">    <canvas id="picker" var="1" width="300" height="300"></canvas>    <p class="controls">        <p><label>r</label> <input type="text" id="rval" /></p>        <p><label>G</label> <input type="text" id="gVal" /></p>        <p><label>B</label> <input type="text" id="bVal" /></p>        <p><label>RGB</label> <input type="text" id="rgbVal" /></p>        <p><label>HEX</label> <input type="text" id="hexVal" /></p><p><span>立即学习</span>“<a href="https://pan.quark.cn/s/cb6835dc7db1" style="text-decoration: underline !important; color: blue; font-weight: bolder;" rel="nofollow" target="_blank">前端免费学习笔记（深入）</a>”；</p>    </p></p>

$(function(){    var bCanPreview = true; // can preview    // create canvas and context objects    var canvas = document.getElementById('picker');    var ctx = canvas.getContext('2d');    // drawing active image    var image = new Image();    image.onload = function () {        ctx.drawImage(image, 0, 0, image.width, image.height); // draw the image on the canvas    }    // select desired colorwheel    var imagesrc="images/colorwheel1.png";    switch ($(canvas).attr('var')) {        case '2':            imagesrc="images/colorwheel2.png";            break;        case '3':            imagesrc="images/colorwheel3.png";            break;        case '4':            imagesrc="images/colorwheel4.png";            break;        case '5':            imagesrc="images/colorwheel5.png";            break;    }    image.src = imageSrc;    $('#picker').mousemove(function(e) { // mouse move handler        if (bCanPreview) {            // get coordinates of current position            var canvasOffset = $(canvas).offset();            var canvasX = Math.floor(e.pageX - canvasOffset.left);            var canvasY = Math.floor(e.pageY - canvasOffset.top);            // get current pixel            var imageData = ctx.getImageData(canvasX, canvasY, 1, 1);            var pixel = imageData.data;            // update preview color            var pixelColor = "rgb("+pixel[0]+", "+pixel[1]+", "+pixel[2]+")";            $('.preview').css('backgroundColor', pixelColor);            // update controls            $('#rVal').val(pixel[0]);            $('#gVal').val(pixel[1]);            $('#bVal').val(pixel[2]);            $('#rgbVal').val(pixel[0]+','+pixel[1]+','+pixel[2]);            var dColor = pixel[2] + 256 * pixel[1] + 65536 * pixel[0];            $('#hexVal').val('#' + ('0000' + dColor.toString(16)).substr(-6));        }    });    $('#picker').click(function(e) { // click event handler        bCanPreview = !bCanPreview;    });    $('.preview').click(function(e) { // preview click        $('.colorpicker').fadeToggle("slow", "linear");        bCanPreview = true;    });});

<canvas id="picker" var="1" width="300" height="300"></canvas><canvas id="picker" var="2" width="300" height="300"></canvas><canvas id="picker" var="3" width="300" height="300"></canvas><canvas id="picker" var="4" width="300" height="300"></canvas><canvas id="picker" var="5" width="300" height="300"></canvas>

$('.preview').click(function(e) { // preview click     $('.colorpicker').fadeToggle("slow", "linear");     bCanPreview = true; });

$('#picker').mousemove(function(e) { // mouse move handler    if (bCanPreview) {        // get coordinates of current position        var canvasOffset = $(canvas).offset();        var canvasX = Math.floor(e.pageX - canvasOffset.left);        var canvasY = Math.floor(e.pageY - canvasOffset.top);        // get current pixel        var imageData = ctx.getImageData(canvasX, canvasY, 1, 1);        var pixel = imageData.data;        // update preview color        var pixelColor = "rgb("+pixel[0]+", "+pixel[1]+", "+pixel[2]+")";        $('.preview').css('backgroundColor', pixelColor);        // update controls        $('#rVal').val(pixel[0]);        $('#gVal').val(pixel[1]);        $('#bVal').val(pixel[2]);        $('#rgbVal').val(pixel[0]+','+pixel[1]+','+pixel[2]);        var dColor = pixel[2] + 256 * pixel[1] + 65536 * pixel[0];        $('#hexVal').val('#' + ('0000' + dColor.toString(16)).substr(-6));    }});$('#picker').click(function(e) { // click event handler    bCanPreview = !bCanPreview;});

/* colorpicker styles */.colorpicker {    background-color: #222222;    border-radius: 5px 5px 5px 5px;    box-shadow: 2px 2px 2px #444444;    color: #FFFFFF;    font-size: 12px;    position: absolute;    width: 460px;}#picker {    cursor: crosshair;    float: left;    margin: 10px;    border: 0;}.controls {    float: right;    margin: 10px;}.controls > p {    border: 1px solid #2F2F2F;    margin-bottom: 5px;    overflow: hidden;    padding: 5px;}.controls label {    float: left;}.controls > p input {    background-color: #121212;    border: 1px solid #2F2F2F;    color: #DDDDDD;    float: right;    font-size: 10px;    height: 14px;    margin-left: 6px;    text-align: center;    text-transform: uppercase;    width: 75px;}.preview {    background: url("../images/select.png") repeat scroll center center transparent;    border-radius: 3px;    box-shadow: 2px 2px 2px #444444;    cursor: pointer;    height: 30px;    width: 30px;}