判断客户端是否安装framework
安装 .NET Framework 3.5 后，MSI 会将“.NET CLR”和版本号添加到 UserAgent 字符串中。下面的示例演示一个嵌入到简单的 HTML 页的脚本。该脚本搜索 UserAgent 字符串以确定是否已安装 .NET Framework 3.5，并在搜索结果中显示状态消息。
<HTML> <HEAD> <TITLE>Test for the .NET Framework 3.5</TITLE> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=utf-8" />
<SCRIPT LANGUAGE="JavaScript">
<!-- var dotNETRuntimeVersion = "3.5.0.0"; function window::onload()
{
if (HasRuntimeVersion(dotNETRuntimeVersion)) { result.innerText = "This machine has the correct version of the .NET Framework 3.5."
} else { result.innerText = "This machine does not have the correct version of the .NET Framework 3.5." + " The required version is v" + dotNETRuntimeVersion + "."; } result.innerText += "\n\nThis machine's userAgent string is: " + navigator.userAgent + "."; } // // Retrieve the version from the user agent string and // compare with the specified version. // function HasRuntimeVersion(versionToCheck) { var userAgentString = navigator.userAgent.match(/.NET CLR [0-9.]+/g); if (userAgentString != null) { var i; for (i = 0; i < userAgentString.length; ++i) { if (CompareVersions(GetVersion(versionToCheck), GetVersion(userAgentString[i])) <= 0) return true; } } return false; } // // Extract the numeric part of the version string. // function GetVersion(versionString) { var numericString = versionString.match(/([0-9]+)\.([0-9]+)\.([0-9]+)/i); return numericString.slice(1); } // // Compare the 2 version strings by converting them to numeric format. // function CompareVersions(version1, version2) { for (i = 0; i < version1.length; ++i) { var number1 = new Number(version1[i]); var number2 = new Number(version2[i]); if (number1 < number2) return -1; if (number1 > number2) return 1; } return 0; } -->
</SCRIPT> </HEAD> <BODY> <div id="result" /> </BODY></HTML>在安装 .NET Framework 3.5 时，客户端计算机配置了用于 Firefox 2.0+ 的插件，该插件使 Firefox 2.0+ 可以承载 XAML 浏览器应用程序 (XBAP)。下面的示例脚本在检查“Windows Presentation Foundation”插件之前，会检查脚本是否由 Firefox 2.0+ 承载。无论结果如何，该脚本都会显示相应的状态消息。
<HTML> <HEAD> <TITLE>Test for the Firefox Plugin for WPF</TITLE> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=utf-8" /> <SCRIPT type="text/javascript"> <!-- function OnLoad() { // Check if browser is Firefox if( navigator.plugins.length == 0 ) { document.writeln("The browser must be Firefox 2.0+."); return; } // Check for WPF plugin and report var msg = "Windows Presentation Foundation Plugin for Mozilla Firefox is "; var wpfPlugin = navigator.plugins["Windows Presentation Foundation"]; if( wpfPlugin != null ) { document.writeln(msg + " installed."); } else { document.writeln(msg + " not installed. Please install or reinstall the .NET Framework 3.5."); } } --> </SCRIPT> </HEAD> <BODY onload="OnLoad()" /></HTML>