<!DOCTYPE HTML>
<html> 
<head> 
    <meta 
charset="utf-8">
    <title>img - load 
event</title>
</head> 
<body>
    <img id="img1" 
src="http://pic1.win4000.com/wallpaper/f/51c3bb99a21ea.jpg">
    <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。
<!DOCTYPE HTML>
<html> 
<head> 
    <meta 
charset="utf-8">
    <title>img - 
readystatechange event</title>
</head> 
<body>
    <img id="img1" 
src="http://pic1.win4000.com/wallpaper/f/51c3bb99a21ea.jpg">
    <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。
<!DOCTYPE HTML>
<html> 
<head> 
    <meta 
charset="utf-8">
    <title>img - complete 
attribute</title>
</head> 
<body>
    <img id="img1" 
src="http://pic1.win4000.com/wallpaper/f/51c3bb99a21ea.jpg">
    <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。

JavaScript判断图片是否加载完成,布布扣,bubuko.com
原文地址:http://www.cnblogs.com/axl234/p/3765684.html