Return array of Property from Object Collection

I have a class with this structure:

public class BusinessObject
{
    public int Column1 { get; set; }
    public int Column2 { get; set; }
    public string Column3 { get; set; }
    public int Column4 { get; set; }   
}

and I have a collection of objects of this type call BusinessObjectCollection. If I want an array of values that are distinct for only Column2... what must I do?

What if I dont know the property开发者_如何学C that I need... so if i have ColumnTitle as a String... and whatever the value of ColumnTitle... I want the distinct values for that property

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Assuming you want the result to be an IEnumerable<BusinessObject>, so that Column2 is only used for implementing distinctness, there are two options:

• Implement IEqualityComparer<BusinessObject> in a way which uses Column2, and pass that into Distinct

• Use DistinctBy from MoreLINQ:

  var distinct = original.DistinctBy(x => x.Column2);
  

Obviously the second is simpler, but it does require an extra library (or copying just the code for DistinctBy).

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This is the type of stuff that makes me really appreciate LINQ:

int[] distinctColumn2 = (from x in BusinessObjectCollection select x.Column2).Distinct().ToArray();

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Can use the pure LINQ distinct.

var result = (from bo in lbo select bo.Column2).Distinct();

Where lbo is a collection of BusinessObjects.

Regards.