C# Accessing management objects in ManagementObjectCollection

Question

I'm trying to access ManagementObjects in ManagementObjectCollection without using a foreach statement, maybe I'm missing something but I can't figure out how to do it, I need to do something like the following:

ManagementObjectSearcher query = new ManagementObjectSearcher(
     "select Name, CurrentClockSpeed from Win32_Processor");

ManagementObjectCollection queryCollection = query.Get();

ManagementObject mo = queryCollection[0];

Solution 1

ManagementObjectCollection implements IEnumerable or ICollection, so either you must iterate it via IEnumerable (ie foreach) or CopyTo an array via ICollection.

However since it supports IEnumerable you can use Linq :

ManagementObject mo = queryCollection.OfType<ManagementObject>().FirstOrDefault()

OfType<ManagementObject> is required because ManagementObjectCollection supports IEnumerable but not IEnumerable of T.

Solution 2

You can not directly call linq from ManagementObjectCollection (nor an integer indexer). You have to cast it to IEnumerable first:

var queryCollection = from ManagementObject x in query.Get()
                      select x;

var manObj = queryCollection.FirstOrDefault();

Solution 3

ManagementObjectCollection does not implements Indexers, but yes you can you FirstOrDefault extension function if you are using linq but geeks who are using .net 3 or earlier (like me still working on 1.1) can use following code, it is standard way of getting first item from any collection implemented IEnumerable interface.

//TODO: Do the Null and Count Check before following lines
IEnumerator enumerator = collection.GetEnumerator();
enumerator.MoveNext();
ManagementObject mo = (ManagementObject)enumerator.Current;

following are two different ways to retrieve ManagementObject from any index

private ManagementObject GetItem(ManagementObjectCollection collection, int index)
{
            //TODO: do null handling 

            IEnumerator enumerator = collection.GetEnumerator();

            int currentIndex = 0;
            while (enumerator.MoveNext())
            {
                if (currentIndex == index)
                {
                    return enumerator.Current as ManagementObject;
                }

                currentIndex++;
            }

            throw new ArgumentOutOfRangeException("Index out of range");
 }

OR

private ManagementObject GetItem(ManagementObjectCollection collection, int index)
{
            //TODO: do null handling 

            int currentIndex = 0;
            foreach (ManagementObject mo in collection)
            {
                if (currentIndex == index)
                {
                    return mo;
                }

                currentIndex++;
            }

            throw new ArgumentOutOfRangeException("Index out of range");
 }