Public NotInheritable Class HttpContext Implements IServiceProvider
Dim instance As HttpContext
public sealed class HttpContext : IServiceProvider
public ref class HttpContext sealed : IServiceProvider
public final class HttpContext implements IServiceProvider
为继承 IHttpModule 和 IHttpHandler 接口的类提供了对当前 HTTP 请求的 HttpContext 对象的引用。该对象提供对请求的内部 Request、Response 和 Server 属性的访问。
下面的代码示例演示如何访问和显示 HttpContext 对象的属性。使用 Page 对象的 Context 属性来访问当前 HTTP 请求的上下文。
<%@ Page Language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) ' The HttpContext associated with the page can be accessed by the Context property. Dim sb As New System.Text.StringBuilder() ' Use the current HttpContext object to determine if custom errors are enabled. sb.Append("Is custom errors enabled: " & _ Context.IsCustomErrorEnabled.ToString() & "<br/>") ' Use the current HttpContext object to determine if debugging is enabled. sb.Append("Is debugging enabled: " & _ Context.IsDebuggingEnabled.ToString() & "<br/>") ' Use the current HttpContext object to access the current TraceContext object. sb.Append("Trace Enabled: " & _ Context.Trace.IsEnabled.ToString() & "<br/>") ' Use the current HttpContext object to access the current HttpApplicationState object. sb.Append("Number of items in Application state: " & _ Context.Application.Count.ToString() & "<br/>") ' Use the current HttpContext object to access the current HttpSessionState object. ' Session state may not be configured. Try sb.Append("Number of items in Session state: " & _ Context.Session.Count.ToString() & "<br/>") Catch ex As Exception sb.Append("Session state not enabled. <br/>") End Try ' Use the current HttpContext object to access the current Cache object. sb.Append("Number of items in the cache: " & _ Context.Cache.Count.ToString() & "<br/>") ' Use the current HttpContext object to determine the timestamp for the current HTTP Request. sb.Append("Timestamp for the HTTP request: " & _ Context.Timestamp.ToString() & "<br/>") ' Assign StringBuilder object to output label. OutputLabel.Text = sb.ToString() End Sub </script> <html > <head runat="server"> <title>HttpContext Example</title> </head> <body> <form id="form1" runat="server"> <div> Using the current HttpContext to get information about the current page. <br /> <asp:Label id="OutputLabel" runat="server"></asp:Label> </div> </form> </body> </html>
<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> protected void Page_Load(object sender, EventArgs e) { // The HttpContext associated with the page can be accessed by the Context property. System.Text.StringBuilder sb = new System.Text.StringBuilder(); // Use the current HttpContext object to determine if custom errors are enabled. sb.Append("Is custom errors enabled: " + Context.IsCustomErrorEnabled.ToString() + "<br/>"); // Use the current HttpContext object to determine if debugging is enabled. sb.Append("Is debugging enabled: " + Context.IsDebuggingEnabled.ToString() + "<br/>"); // Use the current HttpContext object to access the current TraceContext object. sb.Append("Trace Enabled: " + Context.Trace.IsEnabled.ToString() + "<br/>"); // Use the current HttpContext object to access the current HttpApplicationState object. sb.Append("Number of items in Application state: " + Context.Application.Count.ToString() + "<br/>"); // Use the current HttpContext object to access the current HttpSessionState object. // Session state may not be configured. try { sb.Append("Number of items in Session state: " + Context.Session.Count.ToString() + "<br/>"); } catch { sb.Append("Session state not enabled. <br/>"); } // Use the current HttpContext object to access the current Cache object. sb.Append("Number of items in the cache: " + Context.Cache.Count.ToString() + "<br/>"); // Use the current HttpContext object to determine the timestamp for the current HTTP Request. sb.Append("Timestamp for the HTTP request: " + Context.Timestamp.ToString() + "<br/>"); // Assign StringBuilder object to output label. OutputLabel.Text = sb.ToString(); } </script> <html > <head runat="server"> <title>HttpContext Example</title> </head> <body> <form id="form1" runat="server"> <div> Using the current HttpContext to get information about the current page. <br /> <asp:Label id="OutputLabel" runat="server"></asp:Label> </div> </form> </body> </html>
Windows 98、Windows 2000 SP4、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。