js浏览器和浏览器插件检测的方法总结

文/玄魂

前言

首次面对题目所示的需求的时候，头脑中没有任何概念，于是搜索，所有的中文结果都不是很满意。所幸老外的几篇文章还是很有参考价值，虽然最终没有解决我的问题，但是我还是把这几篇文章的内容作了抽取和整理，于是有了本文。主要内容如下：

1.1  浏览器检测

1.2  浏览器插件检测

1.1  浏览器检测

 

（参考：http://www.quirksmode.org/js/detect.html）

对于浏览器的类型和版本的检测，通常我们使用navigator.userAgent属性，但是它不能适用于所有的浏览器，有时还需要使用navigator.vendor、window.opera或者navigator.appVersion属性。这两个属性这里不做详细的说明，我们先看下面的一段代码：

var BrowserDetect = {

    init: function () {

           this.browser = this.searchString(this.dataBrowser) || "An unknown browser";

           this.version = this.searchVersion(navigator.userAgent)

                  || this.searchVersion(navigator.appVersion)

                  || "an unknown version";

           this.OS = this.searchString(this.dataOS) || "an unknown OS";

    },

    searchString: function (data) {

           for (var i=0;i<data.length;i++)   {

                  var dataString = data[i].string;

                  var dataProp = data[i].prop;

                  this.versionSearchString = data[i].versionSearch || data[i].identity;

                  if (dataString) {

                        if (dataString.indexOf(data[i].subString) != -1)

                               return data[i].identity;

                  }

                  else if (dataProp)

                        return data[i].identity;

           }

    },

    searchVersion: function (dataString) {

           var index = dataString.indexOf(this.versionSearchString);

           if (index == -1) return;

           return parseFloat(dataString.substring(index+this.versionSearchString.length+1));

    },

    dataBrowser: [{

                  string: navigator.userAgent,

                  subString: "Chrome",

                  identity: "Chrome"

           },

{

                  prop: window.opera,

                  identity: "Opera",

                  versionSearch: "Version"

           },

（略。。。）

]

};

名为dataBrowser的数组是我们需要检测的浏览器对象，每个对象包含多个属性用来帮助代码从navigator.userAgent或者window.opera或者navigator.vendor属性中提前浏览器类别和版本信息。每个对象包含的属性说明如下：

1)         string和subString。告诉程序在string属性中搜索subString的内容，从而确定浏览器类型。

2)         prop。使用window.opera来判断浏览器类型。

3)         identity。浏览器类型标识字符串。

4)         versionSearch。用来检测浏览器版本的值，如果没有该值，使用identity属性替代。

完整代码如下（更多解释内容，可参考我给出的英文链接）：

var BrowserDetect = {

       init: function () {

              this.browser = this.searchString(this.dataBrowser) || "An unknown browser";

              this.version = this.searchVersion(navigator.userAgent)

                    || this.searchVersion(navigator.appVersion)

                    || "an unknown version";

              this.OS = this.searchString(this.dataOS) || "an unknown OS";

       },

       searchString: function (data) {

              for (var i=0;i<data.length;i++)   {

                    var dataString = data[i].string;

                    var dataProp = data[i].prop;

                    this.versionSearchString = data[i].versionSearch || data[i].identity;

                    if (dataString) {

                           if (dataString.indexOf(data[i].subString) != -1)

                                  return data[i].identity;

                    }

                    else if (dataProp)

                           return data[i].identity;

              }

       },

       searchVersion: function (dataString) {

              var index = dataString.indexOf(this.versionSearchString);

              if (index == -1) return;

              return parseFloat(dataString.substring(index+this.versionSearchString.length+1));

       },

       dataBrowser: [

              {

                    string: navigator.userAgent,

                    subString: "Chrome",

                    identity: "Chrome"

              },

              {      string: navigator.userAgent,

                    subString: "OmniWeb",

                    versionSearch: "OmniWeb/",

                    identity: "OmniWeb"

              },

              {

                    string: navigator.vendor,

                    subString: "Apple",

                    identity: "Safari",

                    versionSearch: "Version"

              },

              {

                     prop: window.opera,

                    identity: "Opera",

                    versionSearch: "Version"

              },

              {

                    string: navigator.vendor,

                    subString: "iCab",

                    identity: "iCab"

              },

              {

                    string: navigator.vendor,

                    subString: "KDE",

                    identity: "Konqueror"

              },

              {

                    string: navigator.userAgent,

                    subString: "Firefox",

                    identity: "Firefox"

              },

              {

                    string: navigator.vendor,

                    subString: "Camino",

                    identity: "Camino"

              },

              {             // for newer Netscapes (6+)

                    string: navigator.userAgent,

                    subString: "Netscape",

                    identity: "Netscape"

              },

              {

                    string: navigator.userAgent,

                    subString: "MSIE",

                    identity: "Explorer",

                    versionSearch: "MSIE"

              },

              {

                    string: navigator.userAgent,

                    subString: "Gecko",

                    identity: "Mozilla",

                    versionSearch: "rv"

              },

              {             // for older Netscapes (4-)

                    string: navigator.userAgent,

                    subString: "Mozilla",

                    identity: "Netscape",

                    versionSearch: "Mozilla"

              }

       ],

       dataOS : [

              {

                    string: navigator.platform,

                    subString: "Win",

                    identity: "Windows"

              },

              {

                    string: navigator.platform,

                    subString: "Mac",

                    identity: "Mac"

              },

              {

                       string: navigator.userAgent,

                       subString: "iPhone",

                       identity: "iPhone/iPod"

           },

              {

                    string: navigator.platform,

                    subString: "Linux",

                    identity: "Linux"

              }

       ]

 

};

BrowserDetect.init();

 

1.2  浏览器插件检测

主要参考文章：http://www.matthewratzloff.com/blog/2007/06/26/detecting-plugins-in-internet-explorer-and-a-few-hints-for-all-the-others/

对于浏览器插件的检测，情况要略微复杂，包括插件是否安装和插件版本的检测，本文只讨论IE、Firefox和Chrome浏览器。在IE浏览器中，插件是作为ActiveXObject存在的，必须创建ActiveXObject对象才能检测插件是否安装；在Firefox和Chrome中，可以使用navigator.plugins属性来枚举安装的插件。对于插件的版本检测，在IE中，可以使用对应的ActiveXObject对象的GetVersions()方法来获取版本信息；在Firefox中，navigator.plugins['插件标识'].version的方法来获取版本；在Chrome中，却没有统一的方法来获取插件版本，有的插件根本无法获取版本信息。

下面是获取浏览器Pdf插件版本信息的代码：

var PdfDetect = {

    GetInfo: function (explorerName) {

        this.pdfVersion = this.searchPdf(explorerName);

    },

    searchPdf: function (explorerName) {

        explorerName = explorerName.toLowerCase();

        if (explorerName != 'explorer' && navigator.plugins.length > 0) {

            var version = 0;

            if (navigator.plugins['Adobe Acrobat'] || navigator.plugins['Adobe PDF Plug-in']) {

                if (explorerName == 'chrome') {

                    //  version = navigator.plugins[i].name.match(/([\d.]+)/) + "<br />"

                    version = 8; //chrome浏览器无法有效检测pdf版本

                }

                else {

                    version = navigator.plugins['Adobe PDF Plug-in'] ? 

                    navigator.plugins['Adobe Acrobat'].version : 

                    navigator.plugins['Adobe Acrobat'].version;

                }

            }

            return version;

        }

        else {

            var contol = null;

            try {

 

                // AcroPDF.PDF is used by version 7 and later

                control = new ActiveXObject('AcroPDF.PDF');

            } catch (e) {

                return 0;

            }

            if (!control) {

                try {

                    // PDF.PdfCtrl is used by version 6 and earlier

                    control = new ActiveXObject('PDF.PdfCtrl');

                } catch (e) {

                    return 0;

                }

            }

            if (control) {

                isInstalled = true;

                version = control.GetVersions().split(',');

                version = version[0].split('=');

                version = parseFloat(version[1]);

                return version;

            }

            return 0;

        }

    }

在上面的代码中，我们可以看到，在IE6和早期版本的浏览器中使用control = new ActiveXObject('PDF.PdfCtrl')来创建Pdf插件对象，在更新版本的IE浏览器中使用control = new ActiveXObject('AcroPDF.PDF')来创建Pdf对象，然后使用

version = control.GetVersions().split(',');

                version = version[0].split('=');

                version = parseFloat(version[1]);

来获取Pdf版本。在Firefox和Chrome中，使用navigator.plugins['Adobe Acrobat'] || navigator.plugins['Adobe PDF Plug-in']来判断是否安装了Pdf插件。在Firefox中，使用

version = navigator.plugins['Adobe PDF Plug-in'] ? 

                    navigator.plugins['Adobe Acrobat'].version : 

                    navigator.plugins['Adobe Acrobat'].version;

来检测Pdf插件的版本信息。

在chrome中，我没有检测Pdf插件的版本。

检测Flash Player插件的代码如下：

var isInstalled = false;
var version = null;
if (window.ActiveXObject) {
var control = null;
try {
control = new ActiveXObject('ShockwaveFlash.ShockwaveFlash');
} catch (e) {
return;
}
if (control) {
isInstalled = true;
version = control.GetVariable('$version').substring(4);
version = version.split(',');
version = parseFloat(version[0] + '.' + version[1]);
}
} else {
//在Firefox和Chrome中使用navigator.plugins["Shockwave Flash"]检测//Flash Player。}

其他插件的检测，参考我给出的英文链接。