var read = new FileReader()
read.readAsDataURL(files)
read.onload = function (e) {
var src = e.target.result
$("#img")..attr("src", src)
}
首先init()函数用于初始化images数组和image的值，本例中主要是利用setSrc()设置图片的src属性值，这样就达到了图片的切换，图片的轮播是使用定时器来时显的！setInterval('play()',500)的意思是每0.5s调用一次play()函数！<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/htmlcharset=UTF-8">
<title>Insert title here</title>
</head>
<script type="text/javascript">
var timeID
var image
var current = 0
var images = new Array(5)
function init(){
for (var i=1i<=5i++){
images[i] = new Image(450,550)
images[i].src = "pictures/"+i+".jpg"
}
image = document.images[0]
}
function setSrc(i){
current = i
//设置图片src的属性，实现图片的切换
image.src = images[i].src
}
function pre(){
if (current <= 0){
alert('已经是第一张了')
}else{
current--
setSrc(current)
}
}
function next(){
if (current >= 5){
alert('已经是最后一张了')
}else{
current++
setSrc(current)
}
}
function play(){
if (current >= 5){
current = 0
}
setSrc(++current)
}
</script>
<body onload="init()">
<input type="button" value="第一张" onclick="setSrc(1)">
<input type="button" value="上一张" onclick="pre()">
<input type="button" value="下一张" onclick="next()">
<input type="button" value="最后一张" onclick="setSrc(5)">
<input type="button" value="幻灯播放" onclick="timeID=setInterval('play()',500)">
<input type="button" value="停止播放" onclick="clearInterval(timeID)">
<div style="border:1px solid bluewidth:450pxheight:550px" id="myPic">
<img src="pictures/1.jpg" />
</div>
</body>
</html>
方法如下。
function convertImgToBase64(url, callback, outputFormat)
{var canvas = document.createElement('CANVAS'),
ctx = canvas.getContext('2d'),
img = new Image
img.crossOrigin = 'Anonymous'
img.onload = function(){canvas.height = img.height
canvas.width = img.width
ctx.drawImage(img,0,0)
var dataURL = canvas.toDataURL(outputFormat || 'image/png')
callback.call(this, dataURL)
canvas = null}
img.src = url}
