基于javascript代码实现通过点击图片显示原图片
废话不多说了，直接给大家贴js实现点击图片显示原图片的代码，具体代码如下所示：
functionDrawImage(ImgD){
varimage=newImage();
image.src=ImgD.src;
varwidth=$(ImgD).attr("width");
varheight=$(ImgD).attr("height");
if(width>100&&height>80){
ImgD.width=100;
ImgD.height=80;
ImgD.alt=image.width+"×"+image.height;
}else{
if(image.width>0&&image.height>0){
flag=true;
if(image.width>300||image.height>200){
ImgD.width=image.width/2;
ImgD.height=image.height/2;
ImgD.alt=image.width+"×"+image.height;
}else{
ImgD.width=image.width;
ImgD.height=image.height;
ImgD.alt=image.width+"×"+image.height;
}
}
}
}
下面分享一段关于js实现上传图片及时预览
<!DOCTYPEhtmlPUBLIC"-//W3C//DTDXHTML1.0Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<htmlxmlns="http://www.w3.org/1999/xhtml">
<head>
<metahttp-equiv="Content-Type"content="text/html;charset=utf-8"/>
<title>图片上传本地预览</title>
<styletype="text/css">
#preview{width:260px;height:190px;border:1pxsolid#000;overflow:hidden;}
#imghead{filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=image);}
</style>
<scripttype="text/javascript">
//图片上传预览IE是用了滤镜。
functionpreviewImage(file)
{
varMAXWIDTH=260;
varMAXHEIGHT=180;
vardiv=document.getElementById('preview');
if(file.files&&file.files[0])
{
div.innerHTML='<imgid=imghead>';
varimg=document.getElementById('imghead');
img.onload=function(){
varrect=clacImgZoomParam(MAXWIDTH,MAXHEIGHT,img.offsetWidth,img.offsetHeight);
img.width=rect.width;
img.height=rect.height;
//img.style.marginLeft=rect.left+'px';
img.style.marginTop=rect.top+'px';
}
varreader=newFileReader();
reader.onload=function(evt){img.src=evt.target.result;}
reader.readAsDataURL(file.files[0]);
}
else//兼容IE
{
varsFilter='filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="';
file.select();
varsrc=document.selection.createRange().text;
div.innerHTML='<imgid=imghead>';
varimg=document.getElementById('imghead');
img.filters.item('DXImageTransform.Microsoft.AlphaImageLoader').src=src;
varrect=clacImgZoomParam(MAXWIDTH,MAXHEIGHT,img.offsetWidth,img.offsetHeight);
status=('rect:'+rect.top+','+rect.left+','+rect.width+','+rect.height);
div.innerHTML="<divid=divheadstyle='width:"+rect.width+"px;height:"+rect.height+"px;margin-top:"+rect.top+"px;"+sFilter+src+"\"'></div>";
}
}
functionclacImgZoomParam(maxWidth,maxHeight,width,height){
varparam={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);
returnparam;
}
</script>
</head>
<body>
<divid="preview">
<imgid="imghead"width=100height=100border=0src='<%=request.getContextPath()%>/images/defaul.jpg'>
</div>
<inputtype="file"onchange="previewImage(this)"/>
</body>
</html>