上传图片并预览

 <div id="preview">
               <img id="imghead" border="0" src="../image/portrait_130.65212649945px_1199882_easyicon.net.png" width="100px" height="100px" onclick="$('#previewImg').click();"/>
                     </div>
    <input name="imgfile" type="file" onchange="previewImage(this)" style="display: none;" id="previewImg"/>

上面是html中的代码

function previewImage(file) {
            debugger;
            var MAXWIDTH = 90;
            var MAXHEIGHT = 90;
            var div = document.getElementById('preview');
            if (file.files && file.files[0]) {
            
                
                div.innerHTML = '<img id=imghead onclick=$("#previewImg").click()>';
                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.marginLeft = rect.left+'px';
                    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 //兼容IE
            {
                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='" + rect.width + "px;height:" + rect.height + "px;margin-top:" + rect.top + "px;" + sFilter + src + ""'></div>";
            }

        }

上面是js代码