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PerformanceCounterCategory.GetCategories Method

Retrieves a list of the performance counter categories that are registered on the local computer.

Namespace:  System.Diagnostics
Assembly:  System (in System.dll)

public static PerformanceCounterCategory[] GetCategories()

Return Value

Type: System.Diagnostics.PerformanceCounterCategory[]
An array of PerformanceCounterCategory objects indicating the categories that are registered on the local computer.

ExceptionCondition
Win32Exception

A call to an underlying system API failed.

UnauthorizedAccessException

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

NoteNote

To read performance counters 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.

The following code example uses the GetCategories method to return an array of PerformanceCounterCategory objects from the local computer or a specified computer. It converts the PerformanceCounterCategory array into an array of category names, which it sorts and displays for the user. The GetCategories overload is selected based on whether a computer name was specified.

public static void Main(string[] args)
{
    string machineName = "";
    PerformanceCounterCategory[] categories;

    // Copy the machine name argument into the local variable. 
    try
    {
        machineName = args[0]=="."? "": args[0];
    }
    catch
    {
    }

    // Generate a list of categories registered on the specified computer. 
    try
    {
        if (machineName.Length > 0)
        {
            categories = PerformanceCounterCategory.GetCategories(machineName);
        }
        else
        {
            categories = PerformanceCounterCategory.GetCategories();
        }
    }
    catch(Exception ex)
    {
        Console.WriteLine("Unable to get categories on " + 
            (machineName.Length > 0 ? "computer \"{0}\":": "this computer:"), machineName);
        Console.WriteLine(ex.Message);
        return;
    }

    Console.WriteLine("These categories are registered on " + 
        (machineName.Length > 0 ? "computer \"{0}\":": "this computer:"), machineName);

    // Create and sort an array of category names. 
    string[] categoryNames = new string[categories.Length];
    int objX;
    for(objX = 0; objX < categories.Length; objX++)
    {
        categoryNames[objX] = categories[objX].CategoryName;
    }
    Array.Sort(categoryNames);

    for(objX = 0; objX < categories.Length; objX++)
    {
        Console.WriteLine("{0,4} - {1}", objX + 1, categoryNames[objX]);
    }
}

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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