这段代码是用HTML5来创建一个网页颜色选择器。首先在Canvas画一幅图，然后添加鼠标事件
“鼠标移动”，“鼠标点击”。在鼠标移动的时候，显示当前划过的颜色预览，在鼠标点击的时候，选中当前颜色，显示颜色的细节。
demo： http://www.oschina.net/uploads/demo/example158/
[代码] [HTML]代码
head>
div>
div>
div>
footer>
body>
html>
|
[CSS]代码
*{ margin:0;
padding:0;
} body { background-color:#bababa;
color:#fff;
font:14px/1.3 Arial,sans-serif;
} footer { background-color:#212121;
bottom:0;
box-shadow: 0 -1px 2px #111111;
display:block;
height:70px;
left:0;
position:fixed;
width:100%;
z-index:100;
} footer h2{
font-size:22px;
font-weight:normal;
left:50%;
margin-left:-400px;
padding:22px 0;
position:absolute;
width:540px;
} footer a.stuts,a.stuts:visited{ border:none;
text-decoration:none;
color:#fcfcfc;
font-size:14px;
left:50%;
line-height:31px;
margin:23px 0 0 110px;
position:absolute;
top:0;
} footer .stuts span { font-size:22px;
font-weight:bold;
margin-left:5px;
} .container { color:#000;
margin:20px auto;
position:relative;
width:730px;
} .column1 {
float:left;
width:500px;
} .column2 {
float:left;
padding-left:20px;
width:170px;
} #panel { border:1px #000 solid;
box-shadow:4px 6px 6px #444444;
cursor:crosshair;
} .column2 > div {
margin-bottom:10px;
} #swImage { border:1px #000 solid;
box-shadow:2px 3px 3px #444444;
cursor:pointer;
height:25px;
line-height:25px;
border-radius:3px;
-moz-border-radius:3px;
-webkit-border-radius:3px;
} #swImage:hover { margin-left:2px;
} #preview { border:1px #000 solid;
box-shadow:2px 3px 3px #444444;
height:80px;
width:80px;
border-radius:3px;
-moz-border-radius:3px;
-webkit-border-radius:3px;
} .column2 input[type=text] {
float:right;
width:110px;
} |
[JavaScript]代码
var canvas;
var ctx;
var images = [ // predefined array of used images
'images/pic1.jpg',
'images/pic2.jpg',
'images/pic3.jpg',
'images/pic4.jpg',
'images/pic5.jpg',
'images/pic6.jpg',
'images/pic7.jpg',
'images/pic8.jpg',
'images/pic9.jpg',
'images/pic10.jpg'
]; var iActiveImage = 0;
$(function(){
// 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
}
image.src = images[iActiveImage];
// creating canvas object
canvas = document.getElementById('panel');
ctx = canvas.getContext('2d');
$('#panel').mousemove(function(e) { // mouse move handler
var canvasOffset = $(canvas).offset();
var canvasX = Math.floor(e.pageX - canvasOffset.left);
var canvasY = Math.floor(e.pageY - canvasOffset.top);
var imageData = ctx.getImageData(canvasX, canvasY, 1, 1);
var pixel = imageData.data;
var pixelColor = "rgba("+pixel[0]+", "+pixel[1]+", "+pixel[2]+", "+pixel[3]+")";
$('#preview').css('backgroundColor', pixelColor);
});
$('#panel').click(function(e) { // mouse click handler
var canvasOffset = $(canvas).offset();
var canvasX = Math.floor(e.pageX - canvasOffset.left);
var canvasY = Math.floor(e.pageY - canvasOffset.top);
var imageData = ctx.getImageData(canvasX, canvasY, 1, 1);
var pixel = imageData.data;
$('#rVal').val(pixel[0]);
$('#gVal').val(pixel[1]);
$('#bVal').val(pixel[2]);
$('#rgbVal').val(pixel[0]+','+pixel[1]+','+pixel[2]);
$('#rgbaVal').val(pixel[0]+','+pixel[1]+','+pixel[2]+','+pixel[3]);
var dColor = pixel[2] + 256 * pixel[1] + 65536 * pixel[0];
$('#hexVal').val( '#' + dColor.toString(16) );
});
$('#swImage').click(function(e) { // switching images
iActiveImage++;
if (iActiveImage >= 10) iActiveImage = 0;
image.src = images[iActiveImage];
});
}); |
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