Question

i have a problem to order a list by certain rule.

Actually i have Links Object List For Example List list ;

Links Class it’s build in this way :

private class Links
 { 
            public Int32 IdHost { get; set; }
            public String Url { get; set; }
 }

Now using this Code i order the list by IdHost.

var listSortedById = source
                     .OrderBy(n => n.IdHost).ToList();

The problem now starting cause i wish that idHost == 2 should be put every 5 element in the list instead one each other.

Update Example

For Example : 2 1 1 1 3 3 3 4 4 4 1 1 1 2 3 3 3 4 4 4 1 1 1 3 3 3 2 4 4 4 i mean put idHost == 2 every 5 elements.

For what concern the element which comes first i would like that it shold be the idHost == 2.
Is there a way to do this with Linq?

Answer 1

Don’t make it so hard on yourself. If you think too hard you’ll reach for really fancy complicated solutions that use LINQ in non-intuitive ways. Instead, KISS.

First, sort the items that don’t have IdHost == 2 and put those items into a list:

var sorted = source.Where(x => x.IdHost != 2)
                   .OrderBy(x => x.IdHost)
                   .ToList();

Then, collect the items that have IdHost == 2:

var twos = source.Where(x => x.IdHost == 2);

Finally, insert these items every 5th position into your list:

int index = 0;
foreach(var two in twos) {
    sorted.Insert(index, two);
    index += 5;
}