一、将图片转成icon码的实现方式
html代码：
<div> <input onchange="previewImage(this,5)" type="file"/> <span></span> </div> <div> <img src="" alt=""/> </div>
js代码
//图片预览功能 function previewImage(file,imgNum) { var MAXWIDTH = 200; var MAXHEIGHT = 200; var div = document.getElementById('preview'+imgNum); if (file.files && file.files[0]) { div.innerHTML ='<img id=imghead'+imgNum+'>'; var img = document.getElementById('imghead'+imgNum+''); 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 // { var sFilter='filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="'; file.select(); var src = document.selection.createRange().text; div.innerHTML = '<img id=imghead'+imgNum+'>'; var img = document.getElementById('imghead2'); 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"+imgNum+"></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; }
二、使用js的另一种方法一次选中多个图片预览展示
<html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>测试页面</title> <script type="text/javascript"> //下面用于多图片上传预览功能 function setImagePreviews(avalue) { var docObj = document.getElementById("doc"); var dd = document.getElementById("dd"); dd.innerHTML = ""; var fileList = docObj.files; for (var i = 0; i < fileList.length; i++) { dd.innerHTML += "<div > <img /> </div>"; var imgObjPreview = document.getElementById("img"+i); if (docObj.files && docObj.files[i]) { //火狐下，直接设img属性 imgObjPreview.style.display = 'block'; imgObjPreview.style.width = '150px'; imgObjPreview.style.height = '180px'; //imgObjPreview.src = docObj.files[0].getAsDataURL(); //火狐7以上版本不能用上面的getAsDataURL()方式获取，需要一下方式 imgObjPreview.src = window.URL.createObjectURL(docObj.files[i]); } else { //IE下，使用滤镜 docObj.select(); var imgSrc = document.selection.createRange().text; alert(imgSrc) var localImagId = document.getElementById("img" + i); //必须设置初始大小 localImagId.style.width = "150px"; localImagId.style.height = "180px"; //图片异常的捕捉，防止用户修改后缀来伪造图片 try { localImagId.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)"; localImagId.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = imgSrc; } catch (e) { alert("您上传的图片格式不正确，请重新选择!"); return false; } imgObjPreview.style.display = 'none'; document.selection.empty(); } } return true; } </script> </head> <body> <div> <input type="file" multiple="multiple" onchange="javascript:setImagePreviews();" accept="image/*" /> <div></div> </div> </body> </html>
以上这篇js前端实现多图图片上传预览的两个方法(推荐)就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持脚本之家。
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