PerformanceCounterCategory Classe

Definição

public ref class PerformanceCounterCategory sealed

public sealed class PerformanceCounterCategory

type PerformanceCounterCategory = class

Public NotInheritable Class PerformanceCounterCategory

Herança

Object

PerformanceCounterCategory

Exemplos

O seguinte exemplo de código determina se a PerformanceCounter e its PerformanceCounterCategory existem no computador local ou noutro computador. Se estes objetos não existirem no computador local, o exemplo cria-os opcionalmente. Utiliza o Exists método para determinar se o PerformanceCounterCategory existe. Se o PerformanceCounterCategory não existir e não for especificado o nome do contador, ou se o computador for uma máquina remota, o exemplo sai.

Se for fornecido um PerformanceCounter nome, o exemplo utiliza o CounterExists método e apresenta o resultado ao utilizador. Se o PerformanceCounter não existir, o utilizador pode eliminar e recriar o PerformanceCounterCategory com o novo PerformanceCounter. Se o utilizador o fizer, a categoria é eliminada usando o Delete método.

Se solicitado, o exemplo cria agora o novo PerformanceCounterCategory e PerformanceCounter usando o Create método. Se for especificado um nome de instância, o exemplo utiliza o InstanceExists método e apresenta o resultado.

using System;
using System.Diagnostics;
using Microsoft.VisualBasic;

class PerfCounterCatCreateExistMod
{

    public static void Main(string[] args)
    {
        string categoryName = "";
        string counterName = "";
        string instanceName = "";
        string machineName = "";
        string categoryHelp = "";
        string counterHelp = "";
        bool objectExists = false;
        PerformanceCounterCategory pcc;
        bool createCategory = false;

        // Copy the supplied arguments into the local variables.
        try
        {
            categoryName = args[0];
            counterName = args[1];
            instanceName = args[2];
            machineName = args[3]=="."? "": args[3];
            categoryHelp = args[4];
            counterHelp = args[5];
        }
        catch(Exception ex)
        {
            // Ignore the exception from non-supplied arguments.
        }

        // Verify that the category name is not blank.
        if (categoryName.Length==0)
        {
            Console.WriteLine("Category name cannot be blank.");
            return;
        }

        // Check whether the specified category exists.
        if (machineName.Length==0)
        {
            objectExists = PerformanceCounterCategory.Exists(categoryName);

        }
        else
        {
            // Handle the exception that is thrown if the computer
            // cannot be found.
            try
            {
                objectExists = PerformanceCounterCategory.Exists(categoryName, machineName);
            }
            catch(Exception ex)
            {
                Console.WriteLine("Error checking for existence of " +
                    "category \"{0}\" on computer \"{1}\":"+"\n" +ex.Message, categoryName, machineName);
                return;
            }
        }

        // Tell the user whether the specified category exists.
        Console.WriteLine("Category \"{0}\" "+ (objectExists? "exists on ": "does not exist on ")+
            (machineName.Length>0? "computer \"{1}\".": "this computer."), categoryName, machineName);

        // If no counter name is given, the program cannot continue.
        if (counterName.Length==0)
        {
            return;
        }

        // A category can only be created on the local computer.
        if (!objectExists)
        {
            if (machineName.Length>0)
            {
                return;
            }
            else
            {
                createCategory = true;
            }
        }
        else
        {
            // Check whether the specified counter exists.
            if (machineName.Length==0)
            {
                objectExists = PerformanceCounterCategory.CounterExists(counterName, categoryName);
            }
            else
            {
                objectExists = PerformanceCounterCategory.CounterExists(counterName, categoryName, machineName);
            }

            // Tell the user whether the counter exists.
            Console.WriteLine("Counter \"{0}\" "+(objectExists? "exists": "does not exist")+
                " in category \"{1}\" on "+(machineName.Length>0? "computer \"{2}\".": "this computer."),
                counterName, categoryName, machineName);

            // If the counter does not exist, consider creating it.
            if (!objectExists)

                // If this is a remote computer,
                // exit because the category cannot be created.
            {
                if (machineName.Length>0)
                {
                    return;
                }
                else
                {
                    // Ask whether the user wants to recreate the category.
                    Console.Write("Do you want to delete and recreate " +
                        "category \"{0}\" with your new counter? [Y/N]: ", categoryName);
                    string userReply = Console.ReadLine();

                    // If yes, delete the category so it can be recreated later.
                    if (userReply.Trim().ToUpper()=="Y")
                    {
                        PerformanceCounterCategory.Delete(categoryName);
                        createCategory = true;
                    }
                    else
                    {
                        return;
                    }
                }
            }
        }

        // Create the category if it was deleted or it never existed.
        if (createCategory)
        {
            pcc = PerformanceCounterCategory.Create(categoryName, categoryHelp, counterName, counterHelp);

            Console.WriteLine("Category \"{0}\" with counter \"{1}\" created.", pcc.CategoryName, counterName);
        }
        else if(instanceName.Length>0)
        {
            if (machineName.Length==0)
            {
                objectExists = PerformanceCounterCategory.InstanceExists(instanceName, categoryName);
            }
            else
            {
                objectExists = PerformanceCounterCategory.InstanceExists(instanceName, categoryName, machineName);
            }

            // Tell the user whether the instance exists.
            Console.WriteLine("Instance \"{0}\" "+(objectExists? "exists": "does not exist")+
                " in category \"{1}\" on " + (machineName.Length>0? "computer \"{2}\".": "this computer."),
                instanceName, categoryName, machineName);
        }
    }
}

Imports System.Diagnostics

Module PerfCounterCatCreateExistMod

    Sub Main(ByVal args() As String)
        Dim categoryName As String = ""
        Dim counterName As String = ""
        Dim instanceName As String = ""
        Dim machineName As String = ""
        Dim categoryHelp As String = ""
        Dim counterHelp As String = ""
        Dim objectExists As Boolean = False
        Dim pcc As PerformanceCounterCategory
        Dim createCategory As Boolean = False

        ' Copy the supplied arguments into the local variables.
        Try
            categoryName = args(0)
            counterName = args(1)
            instanceName = args(2)
            machineName = IIf(args(3) = ".", "", args(3))
            categoryHelp = args(4)
            counterHelp = args(5)
        Catch ex As Exception
            ' Ignore the exception from non-supplied arguments.
        End Try

        ' Verify that the category name is not blank.
        If categoryName.Length = 0 Then
            Console.WriteLine("Category name cannot be blank.")
            Return
        End If

        ' Check whether the specified category exists.
        If machineName.Length = 0 Then
            objectExists = _
                PerformanceCounterCategory.Exists(categoryName)

        Else
            ' Handle the exception that is thrown if the computer 
            ' cannot be found.
            Try
                objectExists = PerformanceCounterCategory.Exists( _
                    categoryName, machineName)
            Catch ex As Exception
                Console.WriteLine("Error checking for existence of " & _
                    "category ""{0}"" on computer ""{1}"":" & vbCrLf & _
                    ex.Message, categoryName, machineName)
                Return
            End Try
        End If

        ' Tell the user whether the specified category exists.
        Console.WriteLine("Category ""{0}"" " & _
            IIf(objectExists, "exists on ", "does not exist on ") & _
            IIf(machineName.Length > 0, _
                "computer ""{1}"".", "this computer."), _
            categoryName, machineName)

        ' If no counter name is given, the program cannot continue.
        If counterName.Length = 0 Then
            Return
        End If

        ' A category can only be created on the local computer.
        If Not objectExists Then
            If machineName.Length > 0 Then
                Return
            Else
                createCategory = True
            End If
        Else
            ' Check whether the specified counter exists.
            If machineName.Length = 0 Then
                objectExists = PerformanceCounterCategory.CounterExists( _
                    counterName, categoryName)
            Else
                objectExists = PerformanceCounterCategory.CounterExists( _
                    counterName, categoryName, machineName)
            End If

            ' Tell the user whether the counter exists.
            Console.WriteLine("Counter ""{0}"" " & _
                IIf(objectExists, "exists", "does not exist") & _
                " in category ""{1}"" on " & _
                IIf(machineName.Length > 0, _
                    "computer ""{2}"".", "this computer."), _
                counterName, categoryName, machineName)

            ' If the counter does not exist, consider creating it.
            If Not objectExists Then

                ' If this is a remote computer, 
                ' exit because the category cannot be created.
                If machineName.Length > 0 Then
                    Return
                Else
                    ' Ask whether the user wants to recreate the category.
                    Console.Write("Do you want to delete and recreate " & _
                        "category ""{0}"" with your new counter? [Y/N]: ", _
                        categoryName)
                    Dim userReply As String = Console.ReadLine()

                    ' If yes, delete the category so it can be recreated later.
                    If userReply.Trim.ToUpper.Chars(0) = "Y" Then
                        PerformanceCounterCategory.Delete(categoryName)
                        createCategory = True
                    Else
                        Return
                    End If
                End If
            End If
        End If

        ' Create the category if it was deleted or it never existed.
        If createCategory Then
            pcc = PerformanceCounterCategory.Create( _
                categoryName, categoryHelp, counterName, counterHelp)

            Console.WriteLine( _
                "Category ""{0}"" with counter ""{1}"" created.", _
                pcc.CategoryName, counterName)

        ElseIf instanceName.Length > 0 Then

            ' If an instance name was given, check whether it exists.
            If machineName.Length = 0 Then
                objectExists = PerformanceCounterCategory.InstanceExists( _
                    instanceName, categoryName)
            Else
                objectExists = PerformanceCounterCategory.InstanceExists( _
                    instanceName, categoryName, machineName)
            End If

            ' Tell the user whether the instance exists.
            Console.WriteLine("Instance ""{0}"" " & _
                IIf(objectExists, "exists", "does not exist") & _
                " in category ""{1}"" on " & _
                IIf(machineName.Length > 0, _
                    "computer ""{2}"".", "this computer."), _
                instanceName, categoryName, machineName)
        End If
    End Sub
End Module

Observações

A PerformanceCounterCategory propriedade da CategoryName instância é exibida no campo Performance Object da caixa de diálogo Add Counter da aplicação Performance Viewer.

A PerformanceCounterCategory aula fornece vários métodos para interagir com contadores e categorias no computador. Os Create métodos permitem-lhe definir categorias personalizadas. O Delete método permite remover categorias do computador. O GetCategories método permite-lhe visualizar a lista de categorias, enquanto ReadCategory recupera todos os dados de contadores e instâncias associados a uma única categoria.

Um contador de desempenho publica dados de desempenho sobre uma aplicação. As categorias incluem componentes físicos (como processadores, discos e memória) e objetos do sistema (como processos e threads). Os contadores do sistema relacionados com o mesmo objeto de desempenho são agrupados numa categoria que indica o seu foco comum. Quando crias uma instância da PerformanceCounter classe, primeiro indicas a categoria com a qual o componente irá interagir e depois escolhes um contador dessa categoria.

Por exemplo, uma categoria contador do Windows é a categoria Memória. Os contadores de sistema dentro desta categoria acompanham dados de memória, como o número de bytes disponíveis e o número de bytes em cache. Se quiser trabalhar com os bytes armazenados em cache na sua aplicação, criaria uma instância do PerformanceCounter componente, ligava-a à categoria Memória e depois escolhia o contador apropriado (neste caso, Bytes em Cache) dessa categoria.

Embora o seu sistema disponibilize muitas mais contracategorias, as categorias com que provavelmente irá interagir com mais frequência são as categorias Cache, Memória, Objetos, PhysicalDisk, Processo, Processador, Servidor, Sistema e Thread.

Ver também

• PerformanceCounter
• CounterCreationDataCollection
• CounterSample