这篇文章主要为大家详细介绍了 js 本地图片预览实现代码, 具有一定的参考价值,感兴趣的小伙伴们可以参考一下
Javascript 是一种由 Netscape 的 LiveScript 发展而来的原型化继承的基于对象的动态类型的区分大小写的客户端脚本语言,主要目的是为了解决服务器端语言,比如 Perl,遗留的速度问题,为客户提供更流畅的浏览效果。
- <!DOCTYPE html>
- <html>
- <head>
- <title>
- </title>
- </head>
- <body>
- <div id="divPreview">
- <img id="imgHeadPhoto" src="noperson.jpg" style="width: 160px; height: 170px; border: solid 1px #d2e2e2;"
- alt="" />
- </div>
- <input type="file" onchange="PreviewImage(this,'imgHeadPhoto','divPreview');"
- size="20" />
- <script type="text/javascript">
- //js本地图片预览,兼容ie[6-9]、火狐、Chrome17+、Opera11+、Maxthon3
- function PreviewImage(fileObj, imgPreviewId, divPreviewId) {
- var allowExtention = ".jpg,.bmp,.gif,.png"; //允许上传文件的后缀名document.getElementById("hfAllowPicSuffix").value;
- var extention = fileObj.value.substring(fileObj.value.lastIndexOf(".") + 1).toLowerCase();
- var browserVersion = window.navigator.userAgent.toUpperCase();
- if (allowExtention.indexOf(extention) > -1) {
- if (fileObj.files) { //HTML5实现预览,兼容chrome、火狐7+等
- if (window.FileReader) {
- var reader = new FileReader();
- reader.onload = function(e) {
- document.getElementById(imgPreviewId).setAttribute("src", e.target.result);
- }
- reader.readAsDataURL(fileObj.files[0]);
- } else if (browserVersion.indexOf("SAFARI") > -1) {
- alert("不支持Safari6.0以下浏览器的图片预览!");
- }
- } else if (browserVersion.indexOf("MSIE") > -1) {
- if (browserVersion.indexOf("MSIE 6") > -1) { //ie6
- document.getElementById(imgPreviewId).setAttribute("src", fileObj.value);
- } else { //ie[7-9]
- fileObj.select();
- if (browserVersion.indexOf("MSIE 9") > -1) fileObj.blur(); //不加上document.selection.createRange().text在ie9会拒绝访问
- var newPreview = document.getElementById(divPreviewId + "New");
- if (newPreview == null) {
- newPreview = document.createElement("div");
- newPreview.setAttribute("id", divPreviewId + "New");
- newPreview.style.width = document.getElementById(imgPreviewId).width + "px";
- newPreview.style.height = document.getElementById(imgPreviewId).height + "px";
- newPreview.style.border = "solid 1px #d2e2e2";
- }
- newPreview.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod='scale',src='" + document.selection.createRange().text + "')";
- var tempDivPreview = document.getElementById(divPreviewId);
- tempDivPreview.parentNode.insertBefore(newPreview, tempDivPreview);
- tempDivPreview.style.display = "none";
- }
- } else if (browserVersion.indexOf("FIREFOX") > -1) { //firefox
- var firefoxVersion = parseFloat(browserVersion.toLowerCase().match(/firefox\/([\d.]+)/)[1]);
- if (firefoxVersion < 7) { //firefox7以下版本
- document.getElementById(imgPreviewId).setAttribute("src", fileObj.files[0].getAsDataURL());
- } else { //firefox7.0+
- document.getElementById(imgPreviewId).setAttribute("src", window.URL.createObjectURL(fileObj.files[0]));
- }
- } else {
- document.getElementById(imgPreviewId).setAttribute("src", fileObj.value);
- }
- } else {
- alert("仅支持" + allowExtention + "为后缀名的文件!");
- fileObj.value = ""; //清空选中文件
- if (browserVersion.indexOf("MSIE") > -1) {
- fileObj.select();
- document.selection.clear();
- }
- fileObj.outerHTML = fileObj.outerHTML;
- }
- return fileObj.value; //返回路径
- }
- </script>
- </body>
- </html>
来源: http://www.phperz.com/article/17/0523/331366.html