PerformanceCounter.NextValue メソッド
カウンタ サンプルを取得し、計算される値を返します。
名前空間: System.Diagnostics
アセンブリ: System (system.dll 内)
構文
'宣言
Public Function NextValue As Single
'使用
Dim instance As PerformanceCounter
Dim returnValue As Single
returnValue = instance.NextValue
public float NextValue ()
public:
float NextValue ()
public float NextValue ()
public function NextValue () : float
戻り値
このカウンタのためにシステムで取得された計算される値の次の値。
例外
| 例外の種類 | 条件 |
|---|---|
インスタンスがパフォーマンス カウンタに正しく関連付けられていません。 |
|
システム API へのアクセス中にエラーが発生しました。 |
|
プラットフォームが Windows 98 または Windows Millennium Edition (Me) です。パフォーマンス カウンタはサポートされません。 |
解説
注意
カウンタの計算される値が 2 回のカウンタ読み取りに依存する場合、最初の読み取りでは 0.0 が返されます。
使用例
Imports System
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Diagnostics
Imports System.Runtime.InteropServices
Imports Microsoft.VisualBasic
Public Class App
Public Shared Sub Main()
CollectSamples()
End Sub
Private Shared Sub CollectSamples()
Dim categoryName as String = "ElapsedTimeSampleCategory"
Dim counterName as String = "ElapsedTimeSample"
If Not PerformanceCounterCategory.Exists(categoryName) Then
Dim CCDC As New CounterCreationDataCollection()
' Add the counter.
Dim ETimeData As New CounterCreationData()
ETimeData.CounterType = PerformanceCounterType.ElapsedTime
ETimeData.CounterName = counterName
CCDC.Add(ETimeData)
' Create the category.
PerformanceCounterCategory.Create(categoryName, _
"Demonstrates ElapsedTime performance counter usage.", CCDC)
Else
Console.WriteLine("Category exists - {0}", categoryName)
End If
' Create the counter.
Dim PC As PerformanceCounter
PC = New PerformanceCounter(categoryName, counterName, False)
' Initialize the counter.
PC.RawValue = Stopwatch.GetTimestamp()
Dim Start As DateTime = DateTime.Now
' Loop for the samples.
Dim j As Integer
For j = 0 To 99
' Output the values.
If j Mod 10 = 9 Then
Console.WriteLine(("NextValue() = " _
+ PC.NextValue().ToString()))
Console.WriteLine(("Actual elapsed time = " _
+ DateTime.Now.Subtract(Start).ToString()))
OutputSample(PC.NextSample())
End If
' Reset the counter every 20th iteration.
If j Mod 20 = 0 Then
PC.RawValue = Stopwatch.GetTimestamp()
Start = DateTime.Now
End If
System.Threading.Thread.Sleep(50)
Next j
Console.WriteLine(("Elapsed time = " + _
DateTime.Now.Subtract(Start).ToString()))
End Sub
Private Shared Sub OutputSample(s As CounterSample)
Console.WriteLine(ControlChars.Lf + ControlChars.Cr + "+++++++")
Console.WriteLine("Sample values - " + ControlChars.Cr _
+ ControlChars.Lf)
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
End Class
using System;
using System.Collections;
using System.Collections.Specialized;
using System.Diagnostics;
using System.Runtime.InteropServices;
public class App
{
public static void Main()
{
CollectSamples();
}
public static void CollectSamples()
{
const String categoryName = "ElapsedTimeSampleCategory";
const String counterName = "ElapsedTimeSample";
if ( !PerformanceCounterCategory.Exists(categoryName) )
{
CounterCreationDataCollection CCDC = new CounterCreationDataCollection();
// Add the counter.
CounterCreationData ETimeData = new CounterCreationData();
ETimeData.CounterType = PerformanceCounterType.ElapsedTime;
ETimeData.CounterName = counterName;
CCDC.Add(ETimeData);
// Create the category.
PerformanceCounterCategory.Create(categoryName,
"Demonstrates ElapsedTime performance counter usage.",
CCDC);
}
else
{
Console.WriteLine("Category exists - {0}", categoryName);
}
// Create the performance counter.
PerformanceCounter PC = new PerformanceCounter(categoryName,
counterName,
false);
// Initialize the counter.
PC.RawValue = Stopwatch.GetTimestamp();
DateTime Start = DateTime.Now;
// Loop for the samples.
for (int j = 0; j < 100; j++)
{
// Output the values.
if ((j % 10) == 9)
{
Console.WriteLine("NextValue() = " + PC.NextValue().ToString());
Console.WriteLine("Actual elapsed time = " + DateTime.Now.Subtract(Start).ToString());
OutputSample(PC.NextSample());
}
// Reset the counter on every 20th iteration.
if (j % 20 == 0)
{
PC.RawValue = Stopwatch.GetTimestamp();
Start = DateTime.Now;
}
System.Threading.Thread.Sleep(50);
}
Console.WriteLine("Elapsed time = " + DateTime.Now.Subtract(Start).ToString());
}
private static void OutputSample(CounterSample s)
{
Console.WriteLine("\r\n+++++++++++");
Console.WriteLine("Sample values - \r\n");
Console.WriteLine(" BaseValue = " + s.BaseValue);
Console.WriteLine(" CounterFrequency = " + s.CounterFrequency);
Console.WriteLine(" CounterTimeStamp = " + s.CounterTimeStamp);
Console.WriteLine(" CounterType = " + s.CounterType);
Console.WriteLine(" RawValue = " + s.RawValue);
Console.WriteLine(" SystemFrequency = " + s.SystemFrequency);
Console.WriteLine(" TimeStamp = " + s.TimeStamp);
Console.WriteLine(" TimeStamp100nSec = " + s.TimeStamp100nSec);
Console.WriteLine("++++++++++++++++++++++");
}
}
#using <System.dll>
using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
using namespace System::Diagnostics;
using namespace System::Runtime::InteropServices;
void OutputSample( CounterSample s )
{
Console::WriteLine( "\r\n+++++++++++" );
Console::WriteLine( "Sample values - \r\n" );
Console::WriteLine( " BaseValue = {0}", s.BaseValue );
Console::WriteLine( " CounterFrequency = {0}", s.CounterFrequency );
Console::WriteLine( " CounterTimeStamp = {0}", s.CounterTimeStamp );
Console::WriteLine( " CounterType = {0}", s.CounterType );
Console::WriteLine( " RawValue = {0}", s.RawValue );
Console::WriteLine( " SystemFrequency = {0}", s.SystemFrequency );
Console::WriteLine( " TimeStamp = {0}", s.TimeStamp );
Console::WriteLine( " TimeStamp100nSec = {0}", s.TimeStamp100nSec );
Console::WriteLine( "++++++++++++++++++++++" );
}
void CollectSamples()
{
String^ categoryName = "ElapsedTimeSampleCategory";
String^ counterName = "ElapsedTimeSample";
// Create the performance counter category.
if ( !PerformanceCounterCategory::Exists( categoryName ) )
{
CounterCreationDataCollection^ CCDC = gcnew CounterCreationDataCollection;
// Add the counter.
CounterCreationData^ ETimeData = gcnew CounterCreationData;
ETimeData->CounterType = PerformanceCounterType::ElapsedTime;
ETimeData->CounterName = counterName;
CCDC->Add( ETimeData );
// Create the category.
PerformanceCounterCategory::Create( categoryName,
"Demonstrates ElapsedTime performance counter usage.",
CCDC );
}
else
{
Console::WriteLine( "Category exists - {0}", categoryName );
}
// Create the performance counter.
PerformanceCounter^ PC = gcnew PerformanceCounter( categoryName,
counterName,
false );
// Initialize the counter.
PC->RawValue = Stopwatch::GetTimestamp();
DateTime Start = DateTime::Now;
// Loop for the samples.
for ( int j = 0; j < 100; j++ )
{
// Output the values.
if ( (j % 10) == 9 )
{
Console::WriteLine( "NextValue() = {0}", PC->NextValue() );
Console::WriteLine( "Actual elapsed time = {0}", DateTime::Now.Subtract( Start ) );
OutputSample( PC->NextSample() );
}
// Reset the counter on every 20th iteration.
if ( j % 20 == 0 )
{
PC->RawValue = Stopwatch::GetTimestamp();
Start = DateTime::Now;
}
System::Threading::Thread::Sleep( 50 );
}
Console::WriteLine( "Elapsed time = {0}", DateTime::Now.Subtract( Start ) );
}
int main()
{
CollectSamples();
}
import System.*;
import System.Collections.*;
import System.Collections.Specialized.*;
import System.Diagnostics.*;
import System.Runtime.InteropServices.*;
public class App
{
public static void main(String[] args)
{
CollectSamples();
} //main
public static void CollectSamples()
{
final String categoryName = "ElapsedTimeSampleCategory";
final String counterName = "ElapsedTimeSample";
if (!(PerformanceCounterCategory.Exists(categoryName))) {
CounterCreationDataCollection ccdc =
new CounterCreationDataCollection();
// Add the counter.
CounterCreationData eTimeData = new CounterCreationData();
eTimeData.set_CounterType(PerformanceCounterType.ElapsedTime);
eTimeData.set_CounterName(counterName);
ccdc.Add(eTimeData);
// Create the category.
PerformanceCounterCategory.Create(categoryName,
"Demonstrates ElapsedTime performance counter usage.", ccdc);
}
else {
Console.WriteLine("Category exists - {0}", categoryName);
}
// Create the performance counter.
PerformanceCounter pc = new PerformanceCounter(categoryName,
counterName, false);
// Initialize the counter.
pc.set_RawValue(Stopwatch.GetTimestamp());
DateTime start = DateTime.get_Now();
// Loop for the samples.
for (int j = 0; j < 100; j++) {
// Output the values.
if (j % 10 == 9) {
Console.WriteLine("NextValue() = " + ((Single)pc.NextValue()).
ToString());
Console.WriteLine("Actual elapsed time = "
+ DateTime.get_Now().Subtract(start).ToString());
OutputSample(pc.NextSample());
}
// Reset the counter on every 20th iteration.
if (j % 20 == 0) {
pc.set_RawValue(Stopwatch.GetTimestamp());
start = DateTime.get_Now();
}
System.Threading.Thread.Sleep(50);
}
Console.WriteLine("Elapsed time = " + DateTime.get_Now().
Subtract(start).ToString());
} //CollectSamples
private static void OutputSample(CounterSample s)
{
Console.WriteLine("\r\n+++++++++++");
Console.WriteLine("Sample values - \r\n");
Console.WriteLine(" BaseValue = " + s.get_BaseValue());
Console.WriteLine(" CounterFrequency = " + s.get_CounterFrequency());
Console.WriteLine(" CounterTimeStamp = " + s.get_CounterTimeStamp());
Console.WriteLine(" CounterType = " + s.get_CounterType());
Console.WriteLine(" RawValue = " + s.get_RawValue());
Console.WriteLine(" SystemFrequency = " + s.get_SystemFrequency());
Console.WriteLine(" TimeStamp = " + s.get_TimeStamp());
Console.WriteLine(" TimeStamp100nSec = " + s.get_TimeStamp100nSec());
Console.WriteLine("++++++++++++++++++++++");
} //OutputSample
} //App
.NET Framework のセキュリティ
- PerformanceCounterPermission (パフォーマンス カウンタ カテゴリを読み取るために必要なアクセス許可)。PerformanceCounterPermissionAccess.Read (関連する列挙体)
プラットフォーム
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
開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。
バージョン情報
.NET Framework
サポート対象 : 2.0、1.1、1.0
参照
関連項目
PerformanceCounter クラス
PerformanceCounter メンバ
System.Diagnostics 名前空間