我正在尝试为iOS移动设备制作HTML5 Canvas颜色选择器的触摸事件,但无法使其正常工作。
我使用了以下代码:http://www.script-tutorials.com/html5-color-picker-canvas/ 我将
我使用了以下代码:http://www.script-tutorials.com/html5-color-picker-canvas/ 我将
mousemove
事件更改为touch move
,但这并没有起作用。我做错了什么? /**
*
* HTML5 Color Picker
*
* Licensed under the MIT license.
* http://www.opensource.org/licenses/mit-license.php
*
* Copyright 2012, Script Tutorials
* http://www.script-tutorials.com/
*/
$(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';
image.src = imageSrc;
$('#picker').touchmove(function(event) { // mouse move handler
event.preventDefault();
var touch = event.originalEvent.changedTouches[0];
if (bCanPreview) {
// get coordinates of current position
var canvasOffset = $(canvas).offset();
var canvasX = Math.floor( touch.pageX - canvasOffset.left);
var canvasY = Math.floor( touch.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;
});
});
HTML5颜色选择器标记:
<div class="container">
<!-- preview element -->
<div class="preview"></div>
<!-- colorpicker element -->
<div class="colorpicker">
<canvas id="picker" var="1" width="300" height="300"></canvas>
<div class="controls" style="display: none;">
<div><label>R</label> <input type="text" id="rVal" /></div>
<div><label>G</label> <input type="text" id="gVal" /></div>
<div><label>B</label> <input type="text" id="bVal" /></div>
<div><label>RGB</label> <input type="text" id="rgbVal" /></div>
</div>
</div>
</div>
var touch = event.originalEvent.changedTouches[0];
有值吗?你有收到任何错误吗? - Cerbrus