Get a page from a collection without going past the last page?

I have a collect开发者_开发技巧ion of items: ICollection<T> MyCollection

I'm wondering if there is a way to get a subcollection of items (paged) without going past the last page... Right now it returns an empty list because I keep going past the available pages.

For example, if MyCollection has 10 items and I ask for Page 5 (3 items per page) I get an empty collection. Instead, I'd really want the last page (which happens to be page 4, 1 item). Not sure what to do here. If there is a LINQ way of doing this that would rock.

Example variables:

int page = 5;
int itemPerPage = 3;
//MyCollection.Count == 10;

Logic:

// make sure there are any items and that itemsPerPage is greater than zero
// to prevent any DivideByZeroExeceptions from being thrown
if (MyCollection.Any() && itemsPerPage > 0)
{
    if (page * itemsPerPage > MyCollection.Count)
    {
        // if page is past collection change to the last page
        page = (int)Math.Ceiling((float)MyCollection.Count / (float)itemsPerPage);
    }
    else if (page < 1) 
    {
        // if page is before collection change to 1
        page = 1;
    }

    // skip pages and select the number of pages
    MyCollection.Skip((page - 1) * itemsPerPage).Take(itemsPerPage);
}

In this case, page = 5, which is outside of the collection (5 * 3 == 12) so page gets reset to 10 divided and rounded up by 3 == 4. Finally it will skip (4 - 1) * 3 == 9 and then take 3, which will be the last page containing 1 item

I usually put this divide-and-round-up logic into an integer extension method:

public static class IntExtensions
{
    public static int DivideByAndRoundUp(this int number, int divideBy)
    {
        return (int)Math.Ceiling((float)number / (float)divideBy);
    }
}

which will let you write page = MyCollection.Count.DivideAndRoundUp(itemsPerPage)

"Pure" LINQ:

var result = (arr.Count > (page - 1) * perPage ? 
            arr.Skip(perPage * (page - 1)) : 
                arr.Skip(arr.Count / perPage * perPage))
                .Take(perPage);