<html>
<head>
<meta http-equiv=
"Content-Type"
content=
"text/html; charset=utf-8"
/>
<title>图片上传本地预览</title>
<style type=
"text/css"
>
#preview{width:260px;height:190px;border:1px solid #000;overflow:hidden;}
#imghead {filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=image);}
</style>
<script type=
"text/javascript"
>
function
previewImage(file)
{
var
MAXWIDTH = 260;
var
MAXHEIGHT = 180;
var
div = document.getElementById(
'preview'
);
if
(file.files && file.files[0])
{
div.innerHTML =
'<img id=imghead>'
;
var
img = document.getElementById(
'imghead'
);
img.onload =
function
(){
var
rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight);
img.width = rect.width;
img.height = rect.height;
img.style.marginTop = rect.top+
'px'
;
}
var
reader =
new
FileReader();
reader.onload =
function
(evt){img.src = evt.target.result;}
reader.readAsDataURL(file.files[0]);
}
else
{
var
sFilter=
'filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="'
;
file.select();
var
src = document.selection.createRange().text;
div.innerHTML =
'<img id=imghead>'
;
var
img = document.getElementById(
'imghead'
);
img.filters.item(
'DXImageTransform.Microsoft.AlphaImageLoader'
).src = src;
var
rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight);
status =(
'rect:'
+rect.top+
','
+rect.left+
','
+rect.width+
','
+rect.height);
div.innerHTML =
"<div id=divhead style='width:"
+rect.width+
"px;height:"
+rect.height+
"px;margin-top:"
+rect.top+
"px;"
+sFilter+src+
"\"'></div>"
;
}
}
function
clacImgZoomParam( maxWidth, maxHeight, width, height ){
var
param = {top:0, left:0, width:width, height:height};
if
( width>maxWidth || height>maxHeight )
{
rateWidth = width / maxWidth;
rateHeight = height / maxHeight;
if
( rateWidth > rateHeight )
{
param.width = maxWidth;
param.height = Math.
round
(height / rateWidth);
}
else
{
param.width = Math.
round
(width / rateHeight);
param.height = maxHeight;
}
}
param.left = Math.
round
((maxWidth - param.width) / 2);
param.top = Math.
round
((maxHeight - param.height) / 2);
return
param;
}
</script>
</head>
<body>
<div id=
"preview"
>
<img id=
"imghead"
width=100 height=100 border=0 src=
'<%=request.getContextPath()%>/images/defaul.jpg'
>
</div>
<input type=
"file"
onchange=
"previewImage(this)"
/>
</body>
</html>