function SaveAs(href,name)
{
var a = window.open(href)
a.document.execCommand('Saveas',true,name)
a.window.close()
return false
}
</script>
<html>
<head>
<meta http-equiv="Content-Type" content="text/htmlcharset=gb2312">
<title>实验</title>
</head>
<body>
<a href="1.jpg" onClick="return SaveAs(this.href,'1.jpg')">下载</a>
</body>
</html>
js没有操作本地文件的权限，可以借助.net,php等后端语言才行的，将图片提交之后，返回个下载地址，window.open就自动下载了。但是图片可以是svg的话
function saveAs(Url,filename){
var blob=new Blob([''], {type:'application/octet-stream'})
var url = webkitURL.createObjectURL(blob)
var a = document.createElementNS(xhtml,'a')
a.href = Url
a.download = filename
var e = document.createEvent('MouseEvents')
e.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null)
a.dispatchEvent(e)
webkitURL.revokeObjectURL(url)
2. saveAs(data,"new.svg")
使用JS实现单击连接保存图片2种形式都可以
第一种：
<script>
function SaveAs5(imgURL)
...{
var oPop = window.open(imgURL,"","width=1, height=1, top=5000, left=5000")
for( oPop.document.readyState != "complete" )
...{
if (oPop.document.readyState == "complete")break
}
oPop.document.execCommand("SaveAs")
oPop.close()
}
</script>
<img src="t_screenshot_17616.jpg" id="DemoImg" border="0" onclick="SaveAs5(this.src)">
第二种：
<script>
function SaveAs5(imgURL)
...{
var oPop = window.open(imgURL,"","width=1, height=1, top=5000, left=5000")
for( oPop.document.readyState != "complete" )
...{
if (oPop.document.readyState == "complete")break
}
oPop.document.execCommand("SaveAs")
oPop.close()
}
</script>
<img src="../t_screenshot_17616.jpg" id="DemoImg" border="0">
<a href="#" onclick="SaveAs5(document.getElementById('DemoImg').src)">点击这里下载图片 </a>
