C# Fastest Convert from Collection to List<T>

Question

What I'd like to avoid:

ManagementClass m = new ManagementClass("Win32_LogicalDisk");

ManagementObjectCollection managementObjects = m.GetInstances();

List<ManagementObject> managementList = new List<ManagementObject>();

foreach(ManagementObject m in managementObjects){

    managementList.Add(m);

}

Isn't there a way to get that collection into a List that looks something like:

List<ManagementObject> managementList = new List<ManagementObjec>(collection_array);

Thanks much!

Answer 1

You could try:

List<ManagementObject> managementList = new List<ManagementObject>(managementObjects.ToArray());

Not sure if .ToArray() is available for the collection. If you do use the code you posted, make sure you initialize the List with the number of existing elements:

List<ManagementObject> managementList = new List<ManagementObject>(managementObjects.Count);  // or .Length

Answer 2

What version of the framework? With 3.5 you could presumably use:

List<ManagementObject> managementList = managementObjects.Cast<ManagementObject>().ToList();

(edited to remove simpler version; I checked and ManagementObjectCollection only implements the non-generic IEnumerable form)

Answer 3

As long as ManagementObjectCollection implements IEnumerable<ManagementObject> you can do:

List<ManagementObject> managementList = new List<ManagementObjec>(managementObjects);

If it doesn't, then you are stuck doing it the way that you are doing it.

Answer 4

managementObjects.Cast<ManagementBaseObject>().ToList(); is a good choice.

You could improve performance by pre-initialising the list capacity:

    public static class Helpers
    {
        public static List<T> CollectionToList<T>(this System.Collections.ICollection other)
        {
            var output = new List<T>(other.Count);

            output.AddRange(other.Cast<T>());

            return output;
        }
    }

Answer 5

you can convert like below code snippet Collection obj=new Collection