一、load事件
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<!DOCTYPE HTML> <html> <head> <meta charset= "utf-8" >
<title>img - load event</title>
</head> <body> <p id= "p1" >loading...</p>
<script type= "text/javascript" >
img1.onload = function () {
p1.innerHTML = ‘loaded‘
}
</script>
</body> </html> |
测试,所有浏览器都显示出了“loaded”,说明所有浏览器都支持img的load事件。
二、readystatechange事件
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<!DOCTYPE HTML> <html> <head> <meta charset= "utf-8" >
<title>img - readystatechange event</title>
</head> <body> <p id= "p1" >loading...</p>
<script type= "text/javascript" >
img1.onreadystatechange = function () {
if (img1.readyState== "complete" ||img1.readyState== "loaded" ){
p1.innerHTML = ‘readystatechange:loaded‘
}
}
</script>
</body> </html> |
readyState为complete和loaded则表明图片已经加载完毕。测试IE6-IE10支持该事件,其它浏览器不支持。
三、img的complete属性
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<!DOCTYPE HTML> <html> <head> <meta charset= "utf-8" >
<title>img - complete attribute</title>
</head> <body> <p id= "p1" >loading...</p>
<script type= "text/javascript" >
function
imgLoad(img, callback) {
var
timer = setInterval( function () {
if
(img.complete) {
callback(img)
clearInterval(timer)
}
}, 50)
}
imgLoad(img1, function () {
p1.innerHTML( ‘加载完毕‘ )
})
</script>
</body> </html> |
轮询不断监测img的complete属性,如果为true则表明图片已经加载完毕,停止轮询。该属性所有浏览器都支持。