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CounterSample Structure
Visual Studio 2008
Defines a structure that holds the raw data for a performance counter.
Assembly: System (in System.dll)
The following example demonstrates the use of the CounterSample class to display data for a performance counter.
Imports System Imports System.Collections Imports System.Collections.Specialized Imports System.Diagnostics _ Public Class App Private Shared avgCounter64Sample As PerformanceCounter Private Shared avgCounter64SampleBase As PerformanceCounter Public Shared Sub Main() Dim samplesList As New ArrayList() 'If the category does not exist, create the category and exit. 'Performance counters should not be created and immediately used. 'There is a latency time to enable the counters, they should be created 'prior to executing the application that uses the counters. 'Execute this sample a second time to use the counters. If Not (SetupCategory()) Then CreateCounters() CollectSamples(samplesList) CalculateResults(samplesList) End If End Sub 'Main Private Shared Function SetupCategory() As Boolean If Not PerformanceCounterCategory.Exists("AverageCounter64SampleCategory") Then Dim counterDataCollection As New CounterCreationDataCollection() ' Add the counter. Dim averageCount64 As New CounterCreationData() averageCount64.CounterType = PerformanceCounterType.AverageCount64 averageCount64.CounterName = "AverageCounter64Sample" counterDataCollection.Add(averageCount64) ' Add the base counter. Dim averageCount64Base As New CounterCreationData() averageCount64Base.CounterType = PerformanceCounterType.AverageBase averageCount64Base.CounterName = "AverageCounter64SampleBase" counterDataCollection.Add(averageCount64Base) ' Create the category. PerformanceCounterCategory.Create("AverageCounter64SampleCategory", _ "Demonstrates usage of the AverageCounter64 performance counter type.", _ PerformanceCounterCategoryType.SingleInstance, counterDataCollection) Return True Else Console.WriteLine("Category exists - AverageCounter64SampleCategory") Return False End If End Function 'SetupCategory Private Shared Sub CreateCounters() ' Create the counters. avgCounter64Sample = New PerformanceCounter("AverageCounter64SampleCategory", "AverageCounter64Sample", False) avgCounter64SampleBase = New PerformanceCounter("AverageCounter64SampleCategory", "AverageCounter64SampleBase", False) avgCounter64Sample.RawValue = 0 avgCounter64SampleBase.RawValue = 0 End Sub 'CreateCounters Private Shared Sub CollectSamples(ByVal samplesList As ArrayList) Dim r As New Random(DateTime.Now.Millisecond) ' Loop for the samples. Dim j As Integer For j = 0 To 99 Dim value As Integer = r.Next(1, 10) Console.Write(j.ToString() + " = " + value.ToString()) avgCounter64Sample.IncrementBy(value) avgCounter64SampleBase.Increment() If j Mod 10 = 9 Then OutputSample(avgCounter64Sample.NextSample()) samplesList.Add(avgCounter64Sample.NextSample()) Else Console.WriteLine() End If System.Threading.Thread.Sleep(50) Next j End Sub 'CollectSamples Private Shared Sub CalculateResults(ByVal samplesList As ArrayList) Dim i As Integer For i = 0 To (samplesList.Count - 1) - 1 ' Output the sample. OutputSample(CType(samplesList(i), CounterSample)) OutputSample(CType(samplesList((i + 1)), CounterSample)) ' Use .NET to calculate the counter value. Console.WriteLine(".NET computed counter value = " + CounterSampleCalculator.ComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString()) ' Calculate the counter value manually. Console.WriteLine("My computed counter value = " + MyComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString()) Next i End Sub 'CalculateResults '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ ' Description - This counter type shows how many items are processed, on average, ' during an operation. Counters of this type display a ratio of the items ' processed (such as bytes sent) to the number of operations completed. The ' ratio is calculated by comparing the number of items processed during the ' last interval to the number of operations completed during the last interval. ' Generic type - Average ' Formula - (N1 - N0) / (D1 - D0), where the numerator (N) represents the number ' of items processed during the last sample interval and the denominator (D) ' represents the number of operations completed during the last two sample ' intervals. ' Average (Nx - N0) / (Dx - D0) ' Example PhysicalDisk\ Avg. Disk Bytes/Transfer '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ Private Shared Function MyComputeCounterValue(ByVal s0 As CounterSample, ByVal s1 As CounterSample) As [Single] Dim numerator As [Single] = CType(s1.RawValue, [Single]) - CType(s0.RawValue, [Single]) Dim denomenator As [Single] = CType(s1.BaseValue, [Single]) - CType(s0.BaseValue, [Single]) Dim counterValue As [Single] = numerator / denomenator Return counterValue End Function 'MyComputeCounterValue ' Output information about the counter sample. Private Shared Sub OutputSample(ByVal s As CounterSample) Console.WriteLine(ControlChars.Lf + ControlChars.Cr + "+++++++++++") Console.WriteLine("Sample values - " + ControlChars.Lf + ControlChars.Cr) Console.WriteLine((" BaseValue = " + s.BaseValue.ToString())) Console.WriteLine((" CounterFrequency = " + s.CounterFrequency.ToString())) Console.WriteLine((" CounterTimeStamp = " + s.CounterTimeStamp.ToString())) Console.WriteLine((" CounterType = " + s.CounterType.ToString())) Console.WriteLine((" RawValue = " + s.RawValue.ToString())) Console.WriteLine((" SystemFrequency = " + s.SystemFrequency.ToString())) Console.WriteLine((" TimeStamp = " + s.TimeStamp.ToString())) Console.WriteLine((" TimeStamp100nSec = " + s.TimeStamp100nSec.ToString())) Console.WriteLine("++++++++++++++++++++++") End Sub 'OutputSample End Class 'App
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.
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