ManagementReferenceAttribute Class

Definition

Namespace:

System.Management.Instrumentation

Assembly:

System.Core.dll

The ManagementReferenceAttribute marks a class member, property or method parameter as a reference to another management object or class.

Note: the WMI .NET libraries are now considered in final state, and no further development, enhancements, or updates will be available for non-security related issues affecting these libraries. The MI APIs should be used for all new development.

public ref class ManagementReferenceAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Parameter | System.AttributeTargets.Property, AllowMultiple=false)]
public sealed class ManagementReferenceAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Parameter | System.AttributeTargets.Property, AllowMultiple=false)>]
type ManagementReferenceAttribute = class
    inherit Attribute

Public NotInheritable Class ManagementReferenceAttribute
Inherits Attribute

Inheritance

Object

Attribute

ManagementReferenceAttribute

Attributes

AttributeUsageAttribute

Examples

This example demonstrates how to use the ManagementReferenceAttribute attribute together with the ManagementQualifierAttribute to create an association WMI class that links two other WMI classes. The example is a decoupled provider that exposes three WMI classes in the root/assoc namespace. The first two classes, NumberPhonetic and NumberLetter, are linked by the last class, LetterPhonetic.

To compile the example, you will need to include references to both System.Management.Instrumentation and System.Configuration.Install. You must run installutil.exe against the resulting executable and ensure that the program is running in order to use the implemented WMI classes.

using System;
using System.Collections;
using System.Management.Instrumentation;

[assembly: WmiConfiguration("root/assoc", HostingModel = ManagementHostingModel.Decoupled)]

[System.ComponentModel.RunInstaller(true)]
public class TheInstaller : DefaultManagementInstaller
{ }

namespace AssocExample
{
    class Program
    {
        static void Main(string[] args)
        {
            InstrumentationManager.RegisterType(typeof(NumberPhonetic));
            InstrumentationManager.RegisterType(typeof(NumberLetter));
            InstrumentationManager.RegisterType(typeof(LetterPhonetic));

            Console.WriteLine("Press enter to exit");
            Console.ReadLine();

            InstrumentationManager.UnregisterType(typeof(NumberPhonetic));
            InstrumentationManager.UnregisterType(typeof(NumberLetter));
            InstrumentationManager.UnregisterType(typeof(LetterPhonetic));

        }
    }

  [ManagementEntity]
    public class NumberPhonetic
    {
        [ManagementKey]
        public int Number;

        [ManagementProbe]
        public string Name;

        [ManagementBind]
        public NumberPhonetic(int Number)
        {
           this.Number = Number;
           if(Number == 1)
           {
              Name = "alpha";
           }
           else if(Number == 2)
           {
              Name = "bravo";
           }
           else
           {
              throw new InstanceNotFoundException();
           }
        }

        [ManagementEnumerator]
        static public IEnumerable EnumerateInstances()
        {
            for (int i = 1; i < 3; i++)
            {
                yield return new NumberPhonetic(i);
            }
        }

    }

    [ManagementEntity]
    public class NumberLetter
    {
        [ManagementKey]
        public int Number;

        [ManagementProbe]
        public string Letter;

        [ManagementBind]
        public NumberLetter(int Number)
        {
           this.Number = Number;
           if(Number == 1)
           {
              Letter = "A";
           }
           else if(Number == 2)
           {
              Letter = "B";
           }
           else
           {
              throw new InstanceNotFoundException();
           }
        }

        [ManagementEnumerator]
        static public IEnumerable EnumerateInstances()
        {
            for (int i = 1; i < 3; i++)
            {
                yield return new NumberLetter(i);
            }
        }

    }

    [ManagementEntity]
    [ManagementQualifier("Association", Flavor = ManagementQualifierFlavors.DisableOverride)]
    public class LetterPhonetic
    {
        [ManagementReference(Type = "NumberLetter")]
        [ManagementKey]
        public string LetterNumber;

        [ManagementReference(Type = "NumberPhonetic")]
        [ManagementKey]
        public string PhoneticNumber;

        [ManagementEnumerator]
        static public IEnumerable EnumerateInstances()
        {
            ArrayList insts = new ArrayList();
            for (int i = 1; i < 3; i++)
            {
                LetterPhonetic inst = new LetterPhonetic();
                inst.LetterNumber = "Letter = " + i;
                inst.PhoneticNumber = "Phonetic = " + i;
                insts.Add(inst);
            }
            return insts;
        }

    }

}

Remarks

You can use this attribute to create association classes as demonstrated in the following example.

Constructors

ManagementReferenceAttribute()

Initializes a new instance of the ManagementReferenceAttribute class. This is the parameterless constructor.

Properties

Type	Gets or sets the name of the referenced type.
TypeId	When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute)

Methods

Equals(Object)	Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute)
GetHashCode()	Returns the hash code for this instance. (Inherited from Attribute)
GetType()	Gets the Type of the current instance. (Inherited from Object)
IsDefaultAttribute()	When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute)
Match(Object)	When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

Explicit Interface Implementations

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)	Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)	Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute)
_Attribute.GetTypeInfoCount(UInt32)	Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)	Provides access to properties and methods exposed by an object. (Inherited from Attribute)