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WebErrorEvent Class

Provides information about systemic errors.

Namespace:  System.Web.Management
Assembly:  System.Web (in System.Web.dll)

[AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
[AspNetHostingPermissionAttribute(SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
public class WebErrorEvent : WebBaseErrorEvent

ASP.NET health monitoring allows production and operations staff to manage deployed Web applications. The System.Web.Management namespace contains the health-event types responsible for packaging application health-status data and the provider types responsible for processing this data. It also contains supporting types that help during the management of health events.

The WebErrorEvent provides information about errors caused by problems with configuration or application code. An example is the error issued by ASP.NET when an error is found in a page.


In most cases you will be able to use the ASP.NET health-monitoring types as implemented, and you will control the health-monitoring system by specifying values in the healthMonitoring configuration section. You can also derive from the health-monitoring types to create your own custom events and providers. For an example of deriving from the WebErrorEvent class, see the example provided in this topic.

The following code example shows how to derive from the WebErrorEvent class to create a custom event.

Also shown is an excerpt of the configuration file that enables ASP.NET to use this custom event.

  enabled="true" heartBeatInterval="0">


    <add  name="SampleWebErrorEvent" type="SamplesAspNet.SampleWebErrorEvent,weberrorevent,Version=1.0.1573.21549, Culture=neutral, PublicKeyToken=2a0b23915ac7352b, processorArchitecture=MSIL"/>

    <add name="Custom"
      minInterval="00:00:00" />

    <clear />

    <add name="Custom Web Error Event" 
      profile="Custom" />

using System;
using System.Text;
using System.Web;
using System.Web.Management;

namespace Samples.AspNet.Management
  // Implements a custom WebErrorEvent class.  

    public class SampleWebErrorEvent : WebErrorEvent
        private StringBuilder eventInfo;

        // Invoked in case of events identified  
        // only by their event code. 
        public SampleWebErrorEvent(string msg, 
            object eventSource, int eventCode, Exception e)
        base(msg, eventSource, eventCode, e)
            // Perform custom initialization.
            eventInfo = new StringBuilder();
                "Event created at: ", EventTime.ToString()));

        // Invoked in case of events identified  
        // by their event code.and  
        // related event detailed code. 
        public SampleWebErrorEvent(string msg, 
            object eventSource, int eventCode, 
            int detailedCode, Exception e):
          base(msg, eventSource, 
            eventCode, detailedCode, e)
            // Perform custom initialization.
            eventInfo = new StringBuilder();
                "Event created at: ", EventTime.ToString()));

        // Raises the SampleWebErrorEvent. 
        public override void Raise()
            // Perform custom processing. 
                "Event raised at: ", EventTime.ToString()));

            // Raise the event. 

        // Obtains the current request information. 
        public string GetRequestInfo()
            string reqInfo = GetRequestInfo();
            return reqInfo;

        // Obtains the current thread information. 
        public string GetThreadInfo()
            string threadInfo = GetThreadInfo();
            return threadInfo;

        // Obtains the current process information. 
        public string GetProcessInfo()
            string procInfo = GetProcessInfo();
            return procInfo;

        //Formats Web request event information.. 
        public override void FormatCustomEventDetails(
            WebEventFormatter formatter)


            // Add custom data.

            formatter.IndentationLevel += 1;
                "** SampleWebErrorEvent Start **");


                "** SampleWebBaseErrorEvent End **");

            formatter.IndentationLevel -= 1;



Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0