Question

I have a class:

public class LevelInfo
    {
        public int Id { get; set; }
        public string HexColor { get; set; }
        public string Caption { get; set; }
        public int MinPrice { get; set; }
    }

I have a collection of LevelInfo. For example, we have the following data:

Id     HexColor     Caption     MinPrice
1       color1       name1         10
2       color2       name2         20
3       color2       name3         10
4       color3       name4         10

I want to get new collection of LevelInfo grouped(not exactly, don’t know how to say properly) by HexColor.
For the data above I want to get the following collection that contain 3 records:

Id     HexColor     Caption     MinPrice
1       color1       name1         10
3       color2       name3         10
4       color3       name3         10

We not select record with Id equals 2 because we have color1 (with Id =1) and it’s have min price.
How can I do this?
Thanks.

Answer 1

So it sounds like you want to group, order within the group by MinPrice, and then select the first element from each group, right? If that’s correct, you want:

var query = from level in levels
            group level by level.HexColor into levels
            select levels.OrderBy(level => level.MinPrice).First();

Alternatively, if you use MoreLINQ you can avoid doing a complete sort by MinPrice, just picking the value with the minimum price:

var query = from level in levels
            group level by level.HexColor into levels
            select levels.MinBy(level => level.MinPrice);