我有一个Windows用户控件，可以从远程服务器的应用程序日志中读取事件。我可以在信息中读取它，并且它看起来很快就会发生，但是线程在此之后会挂起大约30秒并且使我的应用程序不显示日志。
我担心这可能是因为我缺乏处理线程的经验，但我无法确定。我绝对愿意接受我的线程建议。
查看我所指的内容的最简单方法是调用btnClear_click事件处理程序。跳过线程蠕虫洞后，它转到LoadFilteredEvent方法。结果从ManagementObjectSearcher很快加载，但在下一个语句中挂起30到60秒。
Imports System.Management
Public Class LogMonitor
#Region "attributes"
Private _currentWql As StringBuilder
Private _enabled As Boolean
Private _entries As ArrayList
Private _logWatcher As ManagementEventWatcher
Private _machine As StringBuilder
Private _previousFromDate As DateTime
Private _previousToDate As DateTime
Private _previousStatus As Int16
Private _previousMessage As StringBuilder
Private _scope As ManagementScope
Private _service As StringBuilder
Private _tempEntries As ArrayList
Public Event ExportCompleted()
Public Event ExportStarted(ByVal ExportedResultCount As Integer)
Public Event ExportUpdated(ByVal CurrentEntry As Integer)
Public Event FilteringCompleted()
Public Event FilteringStarted(ByVal LogEntryCount As Integer)
Public Event FilteringUpdated(ByVal CurrentEntry As Integer)
#End Region
#Region "constructor"
Public Sub New(ByVal ComputerName As String, ByVal ServiceName As String)
' This call is required by the Windows Form Designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
_machine = New StringBuilder(ComputerName)
_service = New StringBuilder(ServiceName)
Me.Icon = Nothing
Me.Text = ServiceName
_enabled = True
_previousFromDate = Now
_previousToDate = Now
_previousStatus = 0
_previousMessage = New StringBuilder()
_tempEntries = New ArrayList()
Dim compPath As String = "\\" & _machine.ToString & "\root\cimv2"
_scope = New ManagementScope(compPath, New ConnectionOptions())
_scope.Connect()
_logWatcher = New ManagementEventWatcher(New EventQuery(BuildWatcherWql()))
_logWatcher.Scope = _scope
AddHandler _logWatcher.EventArrived, AddressOf EventAdded
Dim watcherThread As New Threading.Thread(AddressOf _logWatcher.Start)
watcherThread.Start()
End Sub
#End Region
#Region "events"
Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click
dtpFilter.Value = Now.ToShortDateString
SetCurrentWqlToCurrent()
_logWatcher.Start()
' use a thread from the application's thread pool
Threading.ThreadPool.QueueUserWorkItem(AddressOf FilterLogWorker)
End Sub
Private Sub btnFilter_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFilter.Click
SetCurrentWqlToFiltered()
If dtpFilter.Value.Equals(Now.ToShortDateString) Then
_logWatcher.Start()
Else
_logWatcher.Stop()
End If
' use a thread from the application's thread pool to load the new working directory
Threading.ThreadPool.QueueUserWorkItem(AddressOf FilterLogWorker)
End Sub
Private Sub btnSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSearch.Click
Dim sf As New SearchFields
sf.FromDate = _previousFromDate
sf.ToDate = _previousToDate
sf.EventStatus = _previousStatus
sf.Message = _previousMessage.ToString
If sf.ShowDialog = Windows.Forms.DialogResult.OK Then
_previousFromDate = sf.FromDate
_previousToDate = sf.ToDate
_previousStatus = sf.EventStatus
_previousMessage = New StringBuilder(sf.Message.Trim)
SetCurrentWqlToSearched()
_logWatcher.Stop()
' use a thread from the application's thread pool to load the new working directory
Threading.ThreadPool.QueueUserWorkItem(AddressOf FilterLogWorker)
End If
End Sub
Private Sub cmExport_ExportToFile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmExport_ExportToFile.Click
If sfdExport.ShowDialog = Windows.Forms.DialogResult.OK Then
ExportEntriesToFile(sfdExport.FileName)
End If
End Sub
Private Sub cmExport_ExportToEmail_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmExport_ExportToEmail.Click
ExportEntriesToEmail()
End Sub
Private Sub cmExport_ExportToExcel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmExport_ExportToExcel.Click
If sfdExcel.ShowDialog = Windows.Forms.DialogResult.OK Then
ExportEntriesToExcel(sfdExcel.FileName)
End If
End Sub
Private Sub EventAdded(ByVal sender As Object, ByVal e As EventArrivedEventArgs)
Dim handler As New ReceiveNewEventHandler(AddressOf ReceiveNewEvent)
Dim args() As Object = {e}
Me.Invoke(handler, args)
End Sub
Private Sub LogMonitor_Disposed(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Disposed
_logWatcher.Stop()
_logWatcher.Dispose()
End Sub
Private Sub LogMonitor_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
dtpFilter.Value = Now.ToShortDateString()
End Sub
Private Sub tvEntries_DoubleClick(ByVal sender As Object, ByVal e As System.EventArgs) Handles tvEntries.DoubleClick
If IsNothing(tvEntries.SelectedNode) = False Then
Dim id As Long = CLng(tvEntries.SelectedNode.Tag)
Dim ev As New EventViewer(_machine.ToString, id)
ev.Show()
End If
End Sub
#End Region
#Region "functions"
Private Sub AddNewEvent(ByVal EventObject As ManagementObject)
tvEntries.Nodes.Add(BuildLogNodeFromObject(EventObject))
End Sub
Private Sub AddNewEvent(ByVal EventProperty As PropertyData)
tvEntries.Nodes.Add(BuildLogNodeFromProperty(EventProperty))
End Sub
Private Function BuildLogNodeFromObject(ByVal EventObject As ManagementObject) As TreeNode
Dim tempGenTime As String = EventObject.GetPropertyValue("TimeGenerated").ToString()
Dim eventGenTime As DateTime = New DateTime(CInt(tempGenTime.Substring(0, 4)),
CInt(tempGenTime.Substring(4, 2)),
CInt(tempGenTime.Substring(6, 2)),
CInt(tempGenTime.Substring(8, 2)),
CInt(tempGenTime.Substring(10, 2)),
CInt(tempGenTime.Substring(12, 2)))
Dim eventMessage As String = EventObject.GetPropertyValue("Message").ToString
Dim newLineIndex As Integer = eventMessage.IndexOf(vbCrLf)
Dim msg As New StringBuilder
msg.Append(eventGenTime.ToString("MM/dd/yyyy HH:mm:ss"))
msg.Append(" - ")
msg.Append(eventMessage.Substring(0, newLineIndex))
If eventMessage.Length > newLineIndex + 2 Then msg.Append("(more)")
Dim myNode As New TreeNode
myNode.Text = msg.ToString
myNode.Tag = EventObject.GetPropertyValue("RecordNumber").ToString
If EventObject.GetPropertyValue("Type").ToString.Equals("Error") Then myNode.ForeColor = Color.Red
If EventObject.GetPropertyValue("Type").ToString.Equals("Warning") Then myNode.ForeColor = Color.Orange
Return myNode
End Function
Private Function BuildLogNodeFromProperty(ByVal EventProperty As PropertyData) As TreeNode
Dim mbo As ManagementBaseObject = CType(EventProperty.Value, ManagementBaseObject)
Dim tempGenTime As String = mbo.Properties("TimeGenerated").Value.ToString()
Dim eventGenTime As DateTime = New DateTime(CInt(tempGenTime.Substring(0, 4)),
CInt(tempGenTime.Substring(4, 2)),
CInt(tempGenTime.Substring(6, 2)),
CInt(tempGenTime.Substring(8, 2)),
CInt(tempGenTime.Substring(10, 2)),
CInt(tempGenTime.Substring(12, 2)))
Dim eventMessage As String = mbo.Properties("Message").Value.ToString()
Dim newLineIndex As Integer = eventMessage.IndexOf(vbCrLf)
Dim msg As New StringBuilder
msg.Append(eventGenTime.ToString("MM/dd/yyyy HH:mm:ss"))
msg.Append(" - ")
msg.Append(eventMessage.Substring(0, newLineIndex))
If eventMessage.Length > newLineIndex + 2 Then msg.Append("(more)")
Dim myNode As New TreeNode
myNode.Text = msg.ToString
myNode.Tag = mbo.Properties("RecordNumber").Value.ToString
If mbo.Properties("Type").Value.ToString.Equals("Error") Then myNode.ForeColor = Color.Red
If mbo.Properties("Type").Value.ToString.Equals("Warning") Then myNode.ForeColor = Color.Orange
Return myNode
End Function
Private Function BuildWatcherWql() As String
Dim wql As New StringBuilder("SELECT TimeGenerated, Message, RecordNumber, Type FROM __InstanceCreationEvent WHERE TargetInstance ISA 'Win32_NTLogEvent' ")
wql.Append("AND TargetInstance.LogFile = 'Application' AND TargetInstance.SourceName = '")
wql.Append(_service.ToString)
wql.Append("'")
Return wql.ToString
End Function
Private Sub DisableControls()
Me.Invoke(New DisableControlsHandler(AddressOf DisableControls_Impl))
End Sub
Private Sub DisableControls_Impl()
Enabled = False
End Sub
Private Sub EnableControls()
Me.Invoke(New EnableControlsHandler(AddressOf EnableControls_Impl))
End Sub
Private Sub EnableControls_Impl()
Enabled = True
End Sub
Private Sub EventLogWorker(ByVal state As Object)
SyncLock tvEntries.GetType
tvEntries.Invoke(CType(AddressOf LoadServiceHistory, MethodInvoker))
End SyncLock
End Sub
Private Sub ExportEntriesToEmail()
RaiseEvent ExportStarted(tvEntries.Nodes.Count)
Try
Dim outlook As Object = CreateObject("Outlook.Application")
Dim mailMsg As Object
Const olMailItem = 0
mailMsg = outlook.CreateItem(olMailItem)
Dim bodyText As New StringBuilder
For i As Integer = 0 To tvEntries.Nodes.Count - 1
bodyText.AppendLine(tvEntries.Nodes(i).Text)
RaiseEvent ExportUpdated(i)
Next
mailMsg.Body = bodyText.ToString
mailMsg.Subject = Me.Text & " exported results"
mailMsg.Display()
mailMsg = Nothing
outlook = Nothing
Catch ex As Exception
MessageBox.Show("Problem exporting to Outlook." & vbCr & ex.Message, "Service Monitor Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
RaiseEvent ExportCompleted()
End Sub
Private Sub ExportEntriesToFile(ByVal FileName As String)
RaiseEvent ExportStarted(tvEntries.Nodes.Count)
Try
Dim myFile As New IO.FileInfo(FileName)
Dim myWriter As IO.TextWriter = myFile.CreateText()
For i As Integer = 0 To tvEntries.Nodes.Count - 1
myWriter.WriteLine(tvEntries.Nodes(i).Text)
RaiseEvent ExportUpdated(i)
Next
myWriter.Close()
myWriter.Dispose()
Catch ex As Exception
MessageBox.Show("Problem exporting to text file." & vbCr & ex.Message, "Service Monitor Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
RaiseEvent ExportCompleted()
End Sub
Private Sub ExportEntriesToExcel(ByVal FileName As String)
RaiseEvent ExportStarted(tvEntries.Nodes.Count)
Dim excel As Object = Nothing
Dim xlWorkbook As Object = Nothing
Dim xlWorksheet As Object = Nothing
Try
'Try to Open Excel, Add a workbook and worksheet
excel = CreateObject("Excel.Application")
xlWorkbook = excel.Workbooks.Add
xlWorksheet = xlWorkbook.Sheets.Item(1)
Catch ex As Exception
MessageBox.Show("Problem exporting to Excel." & vbCr & ex.Message, "Service Monitor Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
Try
If Not IsNothing(xlWorkbook) Then
xlWorkbook.Close() 'If an error occured we want to close the workbook
End If
If Not IsNothing(excel) Then
excel.Quit() 'If an error occured we want to close Excel
End If
Catch
End Try
xlWorksheet = Nothing
xlWorkbook = Nothing
excel = Nothing
RaiseEvent ExportCompleted()
Exit Sub
End Try
Try
excel.DisplayAlerts = False 'This will prevent any message prompts from Excel (IE.."Do you want to save before closing?")
excel.Visible = False 'We don't want the app visible while we are populating it.
For i As Integer = 0 To tvEntries.Nodes.Count - 1
Dim logTimeCell As Object = xlWorksheet.Range("A" & (i + 1))
Dim messageCell As Object = xlWorksheet.Range("B" & (i + 1))
Dim messageParts() As String = tvEntries.Nodes(i).Text.Split("-")
logTimeCell.Value = messageParts(0).Trim
messageCell.Value = messageParts(1).Trim
logTimeCell = Nothing
messageCell = Nothing
RaiseEvent ExportUpdated(i)
Next
Dim outputRange = xlWorksheet.Range("A1:B" & tvEntries.Nodes.Count)
outputRange.Columns.AutoFit()
outputRange = Nothing
xlWorkbook.SaveAs(FileName)
xlWorkbook.Close()
excel.Quit()
Catch ex As Exception
MessageBox.Show("While trying to Export to Excel recieved error:" & ex.Message, "Export to Excel Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
Try
xlWorkbook.Close() 'If an error occured we want to close the workbook
excel.Quit() 'If an error occured we want to close Excel
Catch
End Try
Finally
xlWorksheet = Nothing
xlWorkbook = Nothing
excel = Nothing
End Try
RaiseEvent ExportCompleted()
End Sub
Private Sub FilterLogWorker(ByVal state As Object)
SyncLock tvEntries.GetType
tvEntries.Invoke(CType(AddressOf LoadFilteredEvents, MethodInvoker))
End SyncLock
End Sub
Private Sub InsertNewEvent(ByVal EventObject As ManagementObject)
tvEntries.Nodes.Insert(0, BuildLogNodeFromObject(EventObject))
End Sub
Private Sub InsertNewEvent(ByVal EventProperty As PropertyData)
tvEntries.Nodes.Insert(0, BuildLogNodeFromProperty(EventProperty))
End Sub
Public Sub LoadEntries()
' use a thread from the application's thread pool to load the new working directory
Threading.ThreadPool.QueueUserWorkItem(AddressOf EventLogWorker)
End Sub
Public Sub LoadEntries(ByVal LogEntries As ArrayList)
_entries = LogEntries
LoadEntries()
End Sub
Private Sub LoadFilteredEvents()
Dim search As New ManagementObjectSearcher(_scope.Path.ToString, _currentWql.ToString)
Dim results As ManagementObjectCollection = search.Get
Dim resultCounter As Integer = 0
RaiseFilteringStartedEvent(results.Count)
DisableControls()
tvEntries.Nodes.Clear()
For Each result As ManagementObject In results
AddNewEvent(result)
resultCounter += 1
RaiseFilteringUpdatedEvent(resultCounter)
Next
results.Dispose()
search.Dispose()
EnableControls()
RaiseFilteringCompletedEvent()
End Sub
Private Sub LoadServiceHistory()
tvEntries.Nodes.Clear()
For Each entry As ManagementObject In _entries
AddNewEvent(entry)
Next
_entries.Clear()
End Sub
Private Sub RaiseFilteringCompletedEvent()
Dim handler As New RaiseFilteringCompletedEventHandler(AddressOf RaiseFilteringCompletedEvent_Impl)
Me.Invoke(handler)
End Sub
Private Sub RaiseFilteringCompletedEvent_Impl()
RaiseEvent FilteringCompleted()
End Sub
Private Sub RaiseFilteringStartedEvent(ByVal MaxValue As Integer)
Dim handler As New RaiseFilteringStartedEventHandler(AddressOf RaiseFilteringStartedEvent_Impl)
Dim args() As Object = {MaxValue}
Me.Invoke(handler, args)
End Sub
Private Sub RaiseFilteringStartedEvent_Impl(ByVal MaxValue As Integer)
RaiseEvent FilteringStarted(MaxValue)
End Sub
Private Sub RaiseFilteringUpdatedEvent(ByVal Index As Integer)
Dim handler As New RaiseFilteringUpdatedEventHandler(AddressOf RaiseFilteringUpdatedEvent_Impl)
Dim args() As Object = {Index}
Me.Invoke(handler, args)
End Sub
Private Sub RaiseFilteringUpdatedEvent_Impl(ByVal Index As Integer)
RaiseEvent FilteringUpdated(Index)
End Sub
Private Sub ReceiveNewEvent(ByVal NewEvent As EventArrivedEventArgs)
If _enabled Then
InsertNewEvent(NewEvent.NewEvent.Properties("TargetInstance"))
Else
_tempEntries.Add(NewEvent.NewEvent.Properties("TargetInstance"))
End If
End Sub
Private Sub RelocateTempEntries()
For i As Integer = 0 To _tempEntries.Count - 1
InsertNewEvent(_tempEntries(i))
Next
_tempEntries.Clear()
End Sub
Private Sub SetCurrentWqlToCurrent()
_currentWql = New StringBuilder
With _currentWql
.Append("SELECT TimeGenerated, Message, RecordNumber, Type FROM Win32_NTLogEvent WHERE LogFile = 'Application' AND SourceName = '")
.Append(_service.ToString)
.Append("' AND TimeGenerated > '")
.Append(Now.Year.ToString("0000"))
.Append(Now.Month.ToString("00"))
.Append(Now.Day.ToString("00"))
.Append("'")
End With
End Sub
Private Sub SetCurrentWqlToFiltered()
_currentWql = New StringBuilder
With _currentWql
.Append("SELECT TimeGenerated, Message, RecordNumber, Type FROM Win32_NTLogEvent WHERE LogFile = 'Application' AND SourceName = '")
.Append(_service.ToString)
.Append("' AND TimeGenerated > '")
.Append(dtpFilter.Value.Year.ToString("0000"))
.Append(dtpFilter.Value.Month.ToString("00"))
.Append(dtpFilter.Value.Day.ToString("00"))
.Append("' AND TimeGenerated < '")
Dim filterEnd As DateTime = dtpFilter.Value.AddDays(1)
.Append(filterEnd.Year.ToString("0000"))
.Append(filterEnd.Month.ToString("00"))
.Append(filterEnd.Day.ToString("00"))
.Append("'")
End With
End Sub
Private Sub SetCurrentWqlToSearched()
_currentWql = New StringBuilder
With _currentWql
.Append("SELECT TimeGenerated, Message, RecordNumber, Type FROM Win32_NTLogEvent WHERE LogFile = 'Application' AND SourceName = '")
.Append(_service.ToString)
.Append("' AND TimeGenerated > '")
.Append(_previousFromDate.Year.ToString("0000"))
.Append(_previousFromDate.Month.ToString("00"))
.Append(_previousFromDate.Day.ToString("00"))
.Append("' AND TimeGenerated < '")
Dim toDate As DateTime = _previousToDate.AddDays(1)
.Append(toDate.Year.ToString("0000"))
.Append(toDate.Month.ToString("00"))
.Append(toDate.Day.ToString("00"))
.Append("' ")
Select Case _previousStatus
Case 1
.Append("AND Type = 'Information' ")
Case 2
.Append("AND Type = 'Warning' ")
Case 3
.Append("AND Type = 'Error' ")
End Select
.Append("AND Message LIKE '%")
.Append(_previousMessage.ToString)
.Append("%'")
End With
End Sub
#End Region
#Region "deletegate methods"
Private Delegate Sub DisableControlsHandler()
Private Delegate Sub EnableControlsHandler()
Private Delegate Sub RaiseFilteringCompletedEventHandler()
Private Delegate Sub RaiseFilteringStartedEventHandler(ByVal MaxValue As Integer)
Private Delegate Sub RaiseFilteringUpdatedEventHandler(ByVal Index As Integer)
Private Delegate Sub ReceiveNewEventHandler(ByVal NewEvent As EventArrivedEventArgs)
#End Region
#Region "properties"
Public Property ComputerName() As String
Get
Return _machine.ToString
End Get
Set(ByVal value As String)
_machine = New StringBuilder(value)
End Set
End Property
Public Shadows Property Enabled() As Boolean
Get
Return _enabled
End Get
Set(ByVal value As Boolean)
_enabled = value
dtpFilter.Enabled = value
btnClear.Enabled = value
btnExport.Enabled = value
btnFilter.Enabled = value
btnSearch.Enabled = value
If _enabled = False And _tempEntries.Count > 0 Then
RelocateTempEntries()
End If
End Set
End Property
Public Property LogEntries() As ArrayList
Get
Return _entries
End Get
Set(ByVal value As ArrayList)
_entries = value
End Set
End Property
Public Property ServiceName() As String
Get
Return _service.ToString
End Get
Set(ByVal value As String)
_service = New StringBuilder(value)
Me.Text = value
End Set
End Property
#End Region
Private Sub tmrReconnect_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tmrReconnect.Tick
'reconect the log watcher
_logWatcher.Stop()
GC.Collect()
_logWatcher.Start()
End Sub
End Class
答案 0 :(得分：1)
经过大量时间处理这个问题后，我发现问题是由于返回了大量条目。我不得不将ManagementObjectSearcher设置为不立即返回结果。发生的事情是搜索器对象立即返回，它没有返回所有结果，但是当我去计算结果时，它一直等到进程完成。它实际上没有加速任何事情，但它确实解释了发生了什么。
答案 1 :(得分：0)
结果加载相当快 ManagementObjectSearcher，但它 在这上面挂了30到60秒 下一个陈述。
如果你的意思是它挂在= search.Get上，那就是实际执行搜索时（而不是在你创建ManagementObjectSearcher时。
就是这样......
使用WHERE条件时，WQL查询可能会非常慢。 你应该检查一下这个查询本身是否需要这么长时间。在Windows附带的WMI测试应用程序中尝试几个不同的查询，wbemtest.exe。
Select * from Win32_NTLogEvent - ＆gt;对我来说，花了大约15秒钟返回35K记录 几年前，当我查询大量数据时遇到了问题，我曾试图使用WHERE条件。它完全无法使用。最后，我只是要求WMI中没有条件的所有项目，然后进行计算排序和删除不匹配的项目。它不是“漂亮”（不觉得它应该是这样）但它把时间从20分钟缩短到2-3秒......
答案 2 :(得分：0)
结果加载相当快 ManagementObjectSearcher，但它 在这上面挂了30到60秒 下一个陈述。
如果您的意思是For Each result As ManagementObject In results需要很长时间，那么请查看以下问题：
Invoke”吗？调用是同步的，即在继续处理之前等待函数完成。 “BeginInvoke”是异步调用。