c# - Linq Query Group By and Selecting First Items

Question

I have a String array kinda like this:

// icon, category, tool
String[,] subButtonData = new String[,]
{
    {"graphics/gui/brushsizeplus_icon", "Draw", "DrawBrushPlus"},
    {"graphics/gui/brushsizeminus_icon", "Draw", "DrawBrushMinus"},
    {"graphics/gui/freedraw_icon", "Draw", "DrawFree"},
    {"graphics/gui/linedraw_icon", "Draw", "DrawLine"},
    {"graphics/gui/rectangledraw_icon", "Draw", "DrawRectangle"},
    {"graphics/gui/ellipsedraw_icon", "Draw", "DrawEllipse"},
    {"graphics/gui/brushsizeplus_icon", "Brusher", "BrusherBrushPlus"},
    {"graphics/gui/brushsizeminus_icon", "Brusher", "BrusherBrushMinus"},
    {"graphics/gui/brushsizeplus_icon", "Text", "TextBrushPlus"},
    {"graphics/gui/brushsizeminus_icon", "Text", "TextBrushMinus"},
};

Then I populate a List<Button> with my Button Type named mainButtons

This is how I query for grouping for Category:

var categories = from b in mainButtons
                 group b by b.category into g
                 select new { Category = g.Key, Buttons = g };

How can I select the first item of each group in my main List? (without iterating each and adding to another List?)

Answer 1

var result = list.GroupBy(x => x.Category).Select(x => x.First())