检测 Web 窗体中的浏览器类型

注意   ASP.NET 页框架可以自动确定浏览器功能，并使用此信息为 Web 控件呈现相应的 HTML 元素和属性。有关详细信息，请参见 ASP.NET 服务器控件和浏览器功能。

浏览器和客户端设备被分为两个不同的组：上级和下级。这两个组定义浏览器或客户端设备提供的本机支持的类型，并且它们通常确定从 Web 服务器加载页的表示形式和行为。

视为上级的浏览器和客户端设备通常支持下面至少一项：

• ECMAScript (JScript, JavaScript) 1.2 版。
• HTML 4.0 版
• Microsoft 文档对象模型 (MSDOM)
• 层叠样式表 (CSS)

下级浏览器和客户端设备仅支持：

• HTML 3.2 版

在 Web 窗体页中检测浏览器类型

• 查询 HttpRequest.Browser 属性，该属性包含一个 HttpBrowserCapabilities 对象。在 HTTP 请求过程中，该对象会从浏览器或客户端设备中获取信息，以便让您的应用程序知道浏览器或客户端设备提供的支持类型和级别。

  以下示例显示如何在页上的文本框中显示浏览器信息。

  ' Visual Basic    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click    Dim s As String = ""    With Request.Browser    s &= "Browser Capabilities" & vbCrLf    s &= "Type = " & .Type & vbCrLf    s &= "Name = " & .Browser & vbCrLf    s &= "Version = " & .Version & vbCrLf    s &= "Major Version = " & .MajorVersion & vbCrLf    s &= "Minor Version = " & .MinorVersion & vbCrLf    s &= "Platform = " & .Platform & vbCrLf    s &= "Is Beta = " & .Beta & vbCrLf    s &= "Is Crawler = " & .Crawler & vbCrLf    s &= "Is AOL = " & .AOL & vbCrLf    s &= "Is Win16 = " & .Win16 & vbCrLf    s &= "Is Win32 = " & .Win32 & vbCrLf    s &= "Supports Frames = " & .Frames & vbCrLf    s &= "Supports Tables = " & .Tables & vbCrLf    s &= "Supports Cookies = " & .Cookies & vbCrLf    s &= "Supports VBScript = " & .VBScript & vbCrLf    s &= "Supports JavaScript = " & .JavaScript & vbCrLf    s &= "Supports Java Applets = " & .JavaApplets & vbCrLf    s &= "Supports ActiveX Controls = " & .ActiveXControls & vbCrLf    End With    TextBox1.Text = s    End Sub    // C#    private void Button1_Click(object sender, System.EventArgs e)    {    System.Web.HttpBrowserCapabilities browser = Request.Browser;    string s = "Browser Capabilities\n"    + "Type = "                    + browser.Type + "\n"    + "Name = "                    + browser.Browser + "\n"    + "Version = "                 + browser.Version + "\n"    + "Major Version = "           + browser.MajorVersion + "\n"    + "Minor Version = "           + browser.MinorVersion + "\n"    + "Platform = "                + browser.Platform + "\n"    + "Is Beta = "                 + browser.Beta + "\n"    + "Is Crawler = "              + browser.Crawler + "\n"    + "Is AOL = "                  + browser.AOL + "\n"    + "Is Win16 = "                + browser.Win16 + "\n"    + "Is Win32 = "                + browser.Win32 + "\n"    + "Supports Frames = "         + browser.Frames + "\n"    + "Supports Tables = "         + browser.Tables + "\n"    + "Supports Cookies = "        + browser.Cookies + "\n"    + "Supports VBScript = "       + browser.VBScript + "\n"    + "Supports JavaScript = "     + browser.JavaScript + "\n"    + "Supports Java Applets = "   + browser.JavaApplets + "\n"    + "Supports ActiveX Controls = " + browser.ActiveXControls + "\n";    TextBox1.Text = s;    }