项目中要判断用户是否有安装pdf阅读器以便于打印 或者是否可以打开pdf文档 这个好像没找到什么方法可以判断用户是否可以打开pdf文档? 在网上找了下有判断adobe的? ,不知道有没有直接判断用户是否可以打开pdf文件的方法？

var adobeReaderInfo = {
??? ??? installed : false,
??? ??? version : "0.0",
??? ??? goRedirect:false,
??? ??? getAdobeReader : function(){
??? ??? ??? if (navigator.plugins && navigator.plugins.length) {
??? ??? ??? ??? ??? for (var x = 0; x < navigator.plugins.length; x++) {
??? ??? ??? ??? ??? ??? if (navigator.plugins[x].description.indexOf("Adobe Acrobat") != -1) {
??? ??? ??? ??? ??? ??? ??? adobeReaderInfo.version = parseFloat(navigator.plugins[x].description.split("Version ")[1]);
??? ??? ??? ??? ??? ??? ??? if (adobeReaderInfo.version.toString().length == 1) adobeReaderInfo.version += ".0";
??? ??? ??? ??? ??? ??? ??? adobeReaderInfo.installed = true;
??? ??? ??? ??? ??? ??? ??? break;
??? ??? ??? ??? ??? ??? } else if (navigator.plugins[x].description.indexOf("Adobe PDF Plug-In") != -1) {
??? ??? ??? ??? ??? ??? ??? adobeReaderInfo.installed = true;
??? ??? ??? ??? ??? ??? ??? adobeReaderInfo.version = "8+";
??? ??? ??? ??? ??? ??? ??? break;
??? ??? ??? ??? ??? ??? }
??? ??? ??? ??? ??? }
??? ??? ??? } else if (window.ActiveXObject) {
??? ??? ??? ??? for (x = 2; x < 10; x++) {
??? ??? ??? ??? ??? try {
??? ??? ??? ??? ??? ??? oAcro = eval("new ActiveXObject('PDF.PdfCtrl." + x + "');");
??? ??? ??? ??? ??? ??? if (oAcro) {
??? ??? ??? ??? ??? ??? ??? adobeReaderInfo.installed = true;
??? ??? ??? ??? ??? ??? ??? adobeReaderInfo.version = x + ".0";
??? ??? ??? ??? ??? ??? }
??? ??? ??? ??? ??? }
??? ??? ??? ??? ??? catch (e) { }
??? ??? ??? ??? }
??? ??? ??? ??? try {
??? ??? ??? ??? ??? oAcro4 = new ActiveXObject("PDF.PdfCtrl.1");
??? ??? ??? ??? ??? if (oAcro4) {
??? ??? ??? ??? ??? ??? adobeReaderInfo.installed = true;
??? ??? ??? ??? ??? ??? adobeReaderInfo.version = '4.0';
??? ??? ??? ??? ??? }
??? ??? ??? ??? }
??? ??? ??? ??? catch (e) { }

??? ??? ??? ??? try {
??? ??? ??? ??? ??? oAcro7 = new ActiveXObject('AcroPDF.PDF.1');
??? ??? ??? ??? ??? if (oAcro7) {
??? ??? ??? ??? ??? ??? adobeReaderInfo.installed = true;
??? ??? ??? ??? ??? ??? adobeReaderInfo.version = '7.0';
??? ??? ??? ??? ??? }
??? ??? ??? ??? }
??? ??? ??? ??? catch (e) { }
??? ??? ??? }
??? ??? },
??? ??? judgeAdobe:function(){
??? ??? ??? if(adobeReaderInfo.installed){
??? ??? ??? ??? if(parseInt(adobeReaderInfo.version) < 7){
??? ??? ??? ??? ??? if(confirm("adobe reader 版本太低可能会引起打印的文件布局错位，是否更新到最新版本？")){
??? ??? ??? ??? ??? ??? adobeReaderInfo.goRedirect = false;
??? ??? ??? ??? ??? ??? window.open("http://get.adobe.com/cn/reader/","","");
??? ??? ??? ??? ??? ??? return false;
??? ??? ??? ??? ??? }else{
??? ??? ??? ??? ??? ??? adobeReaderInfo.goRedirect = true;
??? ??? ??? ??? ??? }
??? ??? ??? ??? }else{
??? ??? ??? ??? ??? adobeReaderInfo.goRedirect = true;
??? ??? ??? ??? }
??? ??? ??? }else{
??? ??? ??? ??? if(confirm("请先安装adobe reader")){
??? ??? ??? ??? ??? window.open("http://get.adobe.com/cn/reader/","","");
??? ??? ??? ??? ??? return false;
??? ??? ??? ??? }
??? ??? ??? }
??? ??? }
??? ???
};