检测 IE 7 和 8 问题

Question

问题很简单：我需要 IE 的版本。如果是 7 或更早，我想重定向。下面的代码在所有情况下都有效，除了 IE 8 访问页面时。如果 IE 8 不是从 7 升级的，它将起作用。但是，如果它已升级，则返回的值仍然是 7，即使关于 Internet Explorer 帮助页面显示版本为 8.0.etc。 我被困住了。有什么想法吗？

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"
    },
    {
        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();


var x = (BrowserDetect.browser);
var y = (BrowserDetect.version);
var z = (BrowserDetect.OS);

Y 仍然返回等于 7 的版本，而 IE 实际上是 8。但是，这只发生在 IE 8 从 IE 7 升级后。这让我发疯。为什么它没有看到当前浏览器等于 8...

Answer 1

如果您绝对必须检测浏览器，请使用conditional comments 仅针对 IE：

<!--[if lte IE 7]>
    <script type="text/javascript">
        window.location.href = "http://www.go-away-ie7.com/"
    </script>
<![endif]-->