PerformanceCounterCategory.GetCounters Method

Definition

Namespace:

System.Diagnostics

Assembly:

System.Diagnostics.PerformanceCounter.dll

Retrieves a list of the counters in this performance counter category.

Overloads

GetCounters()	Retrieves a list of the counters in a performance counter category that contains exactly one instance.
GetCounters(String)	Retrieves a list of the counters in a performance counter category that contains one or more instances.

GetCounters()

Source:

PerformanceCounterCategory.cs

Retrieves a list of the counters in a performance counter category that contains exactly one instance.

C#

public System.Diagnostics.PerformanceCounter[] GetCounters();

Returns

PerformanceCounter[]

An array of PerformanceCounter objects indicating the counters that are associated with this single-instance performance counter category.

Exceptions

ArgumentException

The category is not a single instance.

Win32Exception

A call to an underlying system API failed.

InvalidOperationException

The category does not have an associated instance.

UnauthorizedAccessException

Code that is executing without administrative privileges attempted to read a performance counter.

Examples

The following code example gets a list of the PerformanceCounter objects in a PerformanceCounterCategory. It first creates a PerformanceCounterCategory with the appropriate constructor, based on whether a computer name was specified. It then uses the GetCounters method to return an array of PerformanceCounter objects, selecting the GetCounters overload based on whether an instance name was specified.

This GetCounters() overload fails unless it is used with a single-instance category.

C#

public static void Main(string[] args)
{
    string categoryName = "";
    string machineName = "";
    string instanceName = "";
    PerformanceCounterCategory pcc;
    PerformanceCounter[] counters;

    // Copy the supplied arguments into the local variables.
    try
    {
        categoryName = args[0];
        machineName = args[1]=="."? "": args[1];
        instanceName = args[2];
    }
    catch
    {
        // Ignore the exception from non-supplied arguments.
    }

    try
    {
        // Create the appropriate PerformanceCounterCategory object.
        if (machineName.Length>0)
        {
            pcc = new PerformanceCounterCategory(categoryName, machineName);
        }
        else
        {
            pcc = new PerformanceCounterCategory(categoryName);
        }

        // Get the counters for this instance or a single instance
        // of the selected category.
        if (instanceName.Length>0)
        {
            counters = pcc.GetCounters(instanceName);
        }
        else
        {
            counters = pcc.GetCounters();
        }
    }
    catch(Exception ex)
    {
        Console.WriteLine("Unable to get counter information for " +
            (instanceName.Length>0? "instance \"{2}\" in ": "single-instance ") +
            "category \"{0}\" on " + (machineName.Length>0? "computer \"{1}\":": "this computer:"),
            categoryName, machineName, instanceName);
        Console.WriteLine(ex.Message);
        return;
    }

    // Display the counter names if GetCounters was successful.
    if (counters!=null)
    {
        Console.WriteLine("These counters exist in " +
            (instanceName.Length>0? "instance \"{1}\" of": "single instance") +
            " category {0} on " + (machineName.Length>0? "computer \"{2}\":": "this computer:"),
            categoryName, instanceName, machineName);

        // Display a numbered list of the counter names.
        int objX;
        for(objX=0; objX<counters.Length; objX++)
        {
            Console.WriteLine("{0,4} - {1}", objX+1, counters[objX].CounterName);
        }
    }
}

Remarks

For more information about performance object instances, see the PerformanceCounter class overview.

Note

To read performance counters from a non-interactive logon session in Windows Vista and later, Windows XP Professional x64 Edition, or Windows Server 2003, you must either be a member of the Performance Monitor Users group or have administrative privileges.

To avoid having to elevate your privileges to access performance counters in Windows Vista and later, add yourself to the Performance Monitor Users group.

In Windows Vista and later, User Account Control (UAC) determines the privileges of a user. If you are a member of the Built-in Administrators group, you are assigned two run-time access tokens: a standard user access token and an administrator access token. By default, you are in the standard user role. To execute the code that accesses performance counters, you must first elevate your privileges from standard user to administrator. You can do this when you start an application by right-clicking the application icon and indicating that you want to run as an administrator.

See also

• PerformanceCounter

GetCounters(String)

Source:

PerformanceCounterCategory.cs

Retrieves a list of the counters in a performance counter category that contains one or more instances.

C#

public System.Diagnostics.PerformanceCounter[] GetCounters(string instanceName);

Parameters

instanceName

String

The performance object instance for which to retrieve the list of associated counters.

Returns

PerformanceCounter[]

An array of PerformanceCounter objects indicating the counters that are associated with the specified object instance of this performance counter category.

Exceptions

ArgumentNullException

The instanceName parameter is null.

InvalidOperationException

The CategoryName property for this PerformanceCounterCategory instance has not been set.

-or-

The category does not contain the instance that is specified by the instanceName parameter.

Win32Exception

A call to an underlying system API failed.

UnauthorizedAccessException

Code that is executing without administrative privileges attempted to read a performance counter.

Examples

The following code example gets a list of the PerformanceCounter objects in a PerformanceCounterCategory. It first creates a PerformanceCounterCategory with the appropriate constructor, based on whether a computer name was specified. It then uses the GetCounters method to return an array of PerformanceCounter objects, selecting the GetCounters overload based on whether an instance name was specified.

This GetCounters(String) overload fails unless it is used with a category that contains instances.

C#

public static void Main(string[] args)
{
    string categoryName = "";
    string machineName = "";
    string instanceName = "";
    PerformanceCounterCategory pcc;
    PerformanceCounter[] counters;

    // Copy the supplied arguments into the local variables.
    try
    {
        categoryName = args[0];
        machineName = args[1]=="."? "": args[1];
        instanceName = args[2];
    }
    catch
    {
        // Ignore the exception from non-supplied arguments.
    }

    try
    {
        // Create the appropriate PerformanceCounterCategory object.
        if (machineName.Length>0)
        {
            pcc = new PerformanceCounterCategory(categoryName, machineName);
        }
        else
        {
            pcc = new PerformanceCounterCategory(categoryName);
        }

        // Get the counters for this instance or a single instance
        // of the selected category.
        if (instanceName.Length>0)
        {
            counters = pcc.GetCounters(instanceName);
        }
        else
        {
            counters = pcc.GetCounters();
        }
    }
    catch(Exception ex)
    {
        Console.WriteLine("Unable to get counter information for " +
            (instanceName.Length>0? "instance \"{2}\" in ": "single-instance ") +
            "category \"{0}\" on " + (machineName.Length>0? "computer \"{1}\":": "this computer:"),
            categoryName, machineName, instanceName);
        Console.WriteLine(ex.Message);
        return;
    }

    // Display the counter names if GetCounters was successful.
    if (counters!=null)
    {
        Console.WriteLine("These counters exist in " +
            (instanceName.Length>0? "instance \"{1}\" of": "single instance") +
            " category {0} on " + (machineName.Length>0? "computer \"{2}\":": "this computer:"),
            categoryName, instanceName, machineName);

        // Display a numbered list of the counter names.
        int objX;
        for(objX=0; objX<counters.Length; objX++)
        {
            Console.WriteLine("{0,4} - {1}", objX+1, counters[objX].CounterName);
        }
    }
}

Remarks

To represent a single-instance category, pass an empty string ("") for the instanceName parameter.

For more information about performance object instances, see the PerformanceCounter class overview.

Note

To read performance counters from a non-interactive logon session in Windows Vista and later, Windows XP Professional x64 Edition, or Windows Server 2003, you must either be a member of the Performance Monitor Users group or have administrative privileges.

To avoid having to elevate your privileges to access performance counters in Windows Vista and later, add yourself to the Performance Monitor Users group.

In Windows Vista and later, User Account Control (UAC) determines the privileges of a user. If you are a member of the Built-in Administrators group, you are assigned two run-time access tokens: a standard user access token and an administrator access token. By default, you are in the standard user role. To execute the code that accesses performance counters, you must first elevate your privileges from standard user to administrator. You can do this when you start an application by right-clicking the application icon and indicating that you want to run as an administrator.

See also

• PerformanceCounter