Get a list of member variables

This is a discussion on Get a list of member variables within the C# Programming forums, part of the General Programming Boards category; Hey everyone, I've been wondering about this, but can't find anything about it. Basically, I've got a class, and a ...

  1. #1
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    Sep 2007
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    Accessing member variables of a list

    Hey everyone, I've been wondering about this, but can't find anything about it.

    Basically, I've got a class, and a list of that class:

    Code:
    public class Person
    {
        public Rectangle boundingBox;
        public int health;
    }
    
    List<Person> personList = new List<Person>();
    And I've got a function that takes a list of rectangles:

    Code:
    private void CheckBoundingBoxes(List<Rectangle> boundingBoxes)
    {
        // Do stuff...
    }
    Now, is it possible that instead of doing this to generate a list of rectangles based on each persons bounding box:

    Code:
    List<Rectangle> boundingBoxList = new List<Rectangle>(personList.Count);
    
    for (int i = 0; i < personList.Count; ++i)
    {
        boundingBoxList.Add(personList[i].boundingBox);
    }
    
    CheckBoundingBoxes(boundingBoxList);
    I can just access the bounding box variable directly, something like:

    Code:
    CheckBoundingBoxes(new List<Rectangle>( personList { boundingBox } ) );
    to do the same thing?

    I appreciate any help I get in regards to this
    Last edited by HLMetroid; 07-06-2009 at 07:30 PM.

  2. #2
    int x = *((int *) NULL); Cactus_Hugger's Avatar
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    You could probably use a foreach() loop to ease it a bit:
    Code:
    List<Rectangle> boundingBoxList = new List<Rectangle>();
    
    foreach(Person p in personList)
        boundingBoxList.Add(p.boundingBox);
    
    CheckBoundingBoxes(boundingBoxList);
    LINQ might be able to do something like this as well, I believe what would do it is:
    Code:
    from p in personList select p.boundingBox
    ...but I have no idea what type that returns. :-) Regardless, it's probably an IEnumerable<Rectangle>, so you might want to consider having your CheckBoundingBoxes function accept that instead of a list.
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  3. #3
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    Thanks for that, I'll try it out

  4. #4
    Confused Magos's Avatar
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    Use:
    Code:
    using System.Linq;
    
    CheckBoundingBoxes(personList.Select(p => p.boundingBox).ToList());
    MagosX.com

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  5. #5
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    Thanks, that seems like a short way of doing it

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