如何:检测是否已安装 .NET Framework 3.5

在管理员能够在面向 .NET Framework 3.5 的系统上部署 Windows Presentation Foundation(WPF)应用程序之前,必须先确认 .NET Framework 3.5 运行时是否存在。 本主题提供用 HTML/JavaScript 编写的脚本,管理员可以使用该脚本来确定系统上是否存在 .NET Framework 3.5。

注释

有关安装、部署和检测 .NET Framework 的更多详细信息,请参阅 安装面向开发人员的 .NET Framework

示例:

安装 .NET Framework 3.5 后,MSI 会将“.NET CLR”和版本号添加到 UserAgent 字符串。 以下示例显示了嵌入在简单 HTML 页面中的脚本。 该脚本将搜索 UserAgent 字符串以确定是否安装了 .NET Framework 3.5,并在搜索结果上显示状态消息。

注释

此脚本专为 Internet Explorer 设计。 其他浏览器可能不会在 UserAgent 字符串中包含 .NET CLR 信息。

<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>

如果搜索“.NET CLR”版本成功,将显示以下状态消息类型:

This machine has the correct version of the .NET Framework 3.5.

This machine's userAgent string is: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 1.1.4322; InfoPath.2; .NET CLR 3.0.590; .NET CLR 3.5.20726; MS-RTC LM 8).

否则,将显示以下类型的状态消息:

This machine does not have the correct version of the .NET Framework 3.5. The required version is v3.5.0.0.

This machine's userAgent string is: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 1.1.4322; InfoPath.2; .NET CLR 3.0.590; MS-RTC LM 8).

另请参阅