js上传图片预览

Html

Css


    点下面图片

//图片上传预览    IE是用了滤镜。
    function previewImage(file) {
        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='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;
    }

↑上面代码改变，会自动显示代码结果 jQuery调用版本：1.11.3

立即下载

js上传图片预览



代码描述：原声js上传图片预览

很简单一看就能用

0

最新

发表评论全部评论

暂时没有评论！

登录后才可以评论

30秒后在评论吧!

PROMULGATOR

阿库拉玛塔塔

相关代码

js上传图片预览

最新