WebEventProvider 類別

定義

public ref class WebEventProvider abstract : System::Configuration::Provider::ProviderBase

public abstract class WebEventProvider : System.Configuration.Provider.ProviderBase

type WebEventProvider = class
    inherit ProviderBase

Public MustInherit Class WebEventProvider
Inherits ProviderBase

繼承

Object

ProviderBase

WebEventProvider

衍生

System.Web.Management.BufferedWebEventProvider

System.Web.Management.EventLogWebEventProvider

System.Web.Management.IisTraceWebEventProvider

System.Web.Management.TraceWebEventProvider

System.Web.Management.WmiWebEventProvider

範例

以下程式碼範例說明如何從類別 WebEventProvider 衍生出一個自訂提供者，將設定事件寫入本地檔案，必須授予適當的存取權限。 這個自訂提供者範例很簡單，主要目的是讓你作為開發者能完全掌控其基本機制。 在實際情境中，你可以使用這個提供者，尤其是位於 BufferedWebEventProvider的緩衝區提供者範例，作為對應用程式行為的初步探測。 這有助於你在設計階段理解可用資訊;之後你可以將這些資訊轉交給更複雜的醫療提供者。

以下設定檔摘錄展示了一個 healthMonitoring 區段設定，使 ASP.NET 能使用上述定義的自訂提供者來處理所有健康監控事件。

<healthMonitoring
  heartBeatInterval="0"
  enabled="true">

    <providers>

      <add name="SampleWebEventProvider"
        type="SamplesAspNet.SampleEventProvider,webeventprovider, Version=1.0.1773.33989, Culture=neutral, PublicKeyToken=cf85aa6c978d9dea, processorArchitecture=MSIL" />

    </providers>

    <rules>

      <rule
        name="Custom Event Provider"
        eventName="All Events"
        provider="SampleWebEventProvider"
        profile="Default" />
    </rules>

</healthMonitoring>

using System;
using System.Text;
using System.IO;
using System.Web.Management;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Web;

namespace SamplesAspNet
{
  // Implements a custom event provider.
    public class SampleEventProvider : 
        System.Web.Management.WebEventProvider
    {

        // The local path of the file where
        // to store event information.
        private string logFilePath;
    
        // The current number of buffered messages 
        private int msgCounter;

        // The max number of messages to buffere.
        private int maxMsgNumber;

        // The message buffer.
        private System.Collections.Generic.Queue
            <WebBaseEvent> msgBuffer = 
            new Queue<WebBaseEvent>();

        // Initializes the provider.
        public SampleEventProvider(): base()
        {

            // Initialize the local path of the file 
            // that holds event information.
            logFilePath = "C:/test/log.doc";

            // Clear the message buffer.
            msgBuffer.Clear();

            // Initialize the max number of messages
            // to buffer.
            maxMsgNumber = 10;

            // More custom initialization goes here.
        }

        // Flush the input buffer if required.
        public override void Flush()
        {
            // Create a string builder to 
            // hold the event information.
            StringBuilder reData = new StringBuilder();

            // Store custom information.
            reData.Append("SampleEventProvider processing." +
                Environment.NewLine);
            reData.Append("Flush done at: {0}" +
                DateTime.Now.TimeOfDay.ToString() +
                Environment.NewLine);
            
            foreach (WebBaseEvent e in msgBuffer)
            {
                // Store event data.
                reData.Append(e.ToString());
            }

            // Store the information in the specified file.
            StoreToFile(reData, logFilePath, FileMode.Append);

            // Reset the message counter.
            msgCounter = 0;
            
            // Clear the buffer.
            msgBuffer.Clear();
        }


        // Shutdown the provider.
        public override void Shutdown()
        {
            Flush();
        }


        // Process the event that has been raised.
        public override void ProcessEvent(WebBaseEvent raisedEvent)
        { 
            if (msgCounter < maxMsgNumber)
            {
                // Buffer the event information.
                msgBuffer.Enqueue(raisedEvent);
                // Increment the message counter.
                msgCounter += 1;
            }
            else
            {
                // Flush the buffer.
                Flush();
            }
        }



        // Store event information in a local file.
        private void StoreToFile(StringBuilder text, 
            string filePath, FileMode mode)
        {
            int writeBlock;
            int startIndex;

            try
            {

                writeBlock = 256;
                startIndex = 0;

                // Open or create the local file 
                // to store the event information.
                FileStream fs = new FileStream(filePath, 
                    mode, FileAccess.Write);

                // Lock the file for writing.
                fs.Lock(startIndex, writeBlock);

                // Create a stream writer
                StreamWriter writer = new StreamWriter(fs);

                // Set the file pointer to the current 
                // position to keep adding data to it. 
                // If you want to rewrite the file use 
                // the following statement instead.
                // writer.BaseStream.Seek (0, SeekOrigin.Begin);
                writer.BaseStream.Seek(0, SeekOrigin.Current);

                //If the file already exists it must not 
                // be write protected otherwise  
                // the following write operation fails silently.
                writer.Write(text.ToString());

                // Update the underlying file
                writer.Flush();

                // Unlock the file for other processes.
                fs.Unlock(startIndex, writeBlock);

                // Close the stream writer and the underlying file     
                writer.Close();

                fs.Close();
            }
            catch (Exception e)
            {
                throw new Exception(
                    "SampleEventProvider.StoreToFile: " 
                    + e.ToString());
            }
        }
    }
}

Imports System.Text
Imports System.IO
Imports System.Web.Management
Imports System.Collections.Generic
Imports System.Collections.Specialized
Imports System.Web



' Implements a custom event provider.

Public Class SampleEventProvider
    Inherits System.Web.Management.WebEventProvider
    
    ' The local path of the file where
    ' to store event information.
    Private logFilePath As String
    
    ' The current number of buffered messages 
    Private msgCounter As Integer
    
    ' The max number of messages to buffere.
    Private maxMsgNumber As Integer
    
    ' The message buffer.
    '  private System.Collections.Generic.Queue
    Private msgBuffer _
    As System.Collections.Generic.Queue( _
    Of System.Web.Management.WebBaseEvent) = _
    New System.Collections.Generic.Queue( _
    Of System.Web.Management.WebBaseEvent)


    ' Initializes the provider.
    Public Sub New() 
        
        ' Initialize the local path of the file 
        ' that holds event information.
        logFilePath = "C:/test/log.doc"
        
        ' Clear the message buffer.
        msgBuffer.Clear()
        
        ' Initialize the max number of messages
        ' to buffer.
        maxMsgNumber = 10
    
    End Sub
     
    ' More custom initialization goes here.
    
    ' Flush the input buffer if required.
    Public Overrides Sub Flush() 
        ' Create a string builder to 
        ' hold the event information.
        Dim reData As New StringBuilder()
        
        ' Store custom information.
        reData.Append( _
        "SampleEventProvider processing." + _
        Environment.NewLine)

        reData.Append( _
        "Flush done at: {0}" + _
        DateTime.Now.TimeOfDay.ToString() + _
        Environment.NewLine)
        
        Dim e As WebBaseEvent
        For Each e In  msgBuffer
            ' Store event data.
            reData.Append(e.ToString())
        Next e
        
        ' Store the information in the specified file.
        StoreToFile(reData, logFilePath, FileMode.Append)
        
        ' Reset the message counter.
        msgCounter = 0
        
        ' Clear the buffer.
        msgBuffer.Clear()
    
    End Sub
     
    ' Shutdown the provider.
    Public Overrides Sub Shutdown() 
        Flush()
    
    End Sub
    
    ' Process the event that has been raised.
    Public Overrides Sub ProcessEvent( _
    ByVal raisedEvent As WebBaseEvent)

        If msgCounter < maxMsgNumber Then
            ' Buffer the event information.
            msgBuffer.Enqueue(raisedEvent)
            ' Increment the message counter.
            msgCounter += 1
        Else
            ' Flush the buffer.
            Flush()
        End If

    End Sub
    
    
    ' Store event information in a local file.
    Private Sub StoreToFile( _
    ByVal [text] As StringBuilder, _
    ByVal filePath As String, _
    ByVal mode As FileMode)
        Dim writeBlock As Integer
        Dim startIndex As Integer

        Try

            writeBlock = 256
            startIndex = 0

            ' Open or create the local file 
            ' to store the event information.
            Dim fs As New FileStream( _
            filePath, mode, FileAccess.Write)

            ' Lock the file for writing.
            fs.Lock(startIndex, writeBlock)

            ' Create a stream writer
            Dim writer As New StreamWriter(fs)

            ' Set the file pointer to the current 
            ' position to keep adding data to it. 
            ' If you want to rewrite the file use 
            ' the(following) statement instead.
            ' writer.BaseStream.Seek (0, SeekOrigin.Begin);
            writer.BaseStream.Seek(0, SeekOrigin.Current)

            'If the file already exists it must 
            'not be write protected, otherwise  
            'the following write operation fails silently.
            writer.Write([text].ToString())

            ' Update the underlying file
            writer.Flush()

            ' Unlock the file for other processes.
            fs.Unlock(startIndex, writeBlock)

            ' Close the stream writer and the underlying file     
            writer.Close()

            fs.Close()
        Catch e As Exception
            Throw New Exception( _
            "SampleEventProvider.StoreToFile: " + _
            e.ToString())
        End Try

    End Sub
End Class

備註

ASP.NET 健康監控讓生產與營運人員能管理已部署的網頁應用程式。 System.Web.Management命名空間包含負責包裝應用程式健康狀態資料的健康事件類型，以及負責處理這些資料的提供者類型。 同時也包含協助健康事件管理的支援類型。

如果你想自訂健康事件處理，可以從該 WebEventProvider 類別衍生出自己的自訂提供者。

另請參閱

• ASP.NET 狀況監控 概觀
• 範例：自訂事件提供者
• 安裝與配置 ASP.NET 供應商