CODEWITHSUNDEEP
c#linq
Brendan Gooden
Brendan Gooden

Reputation: 1561

Linq on Custom Class List

How would I edit the method ClosestColor to accept the parameter List<DuluxColours> instead of List<Color>?

I need the method ClosestColor to return the color name from my List<DuluxColours>

Is this even possible? My Linq proficiency is somewhat lacking :)

Thanks for any help!

public int ClosestColor(List<Color> colours, Color target)
{

    var colorDiffs = colours.Select(n => ColorDiff(n, target)).Min(n => n);
    return colours.FindIndex(n => ColorDiff(n, target) == colorDiffs);
}

public int ColorDiff(Color c1, Color c2)
{
    return (int)Math.Sqrt((c1.R - c2.R) * (c1.R - c2.R)
                           + (c1.G - c2.G) * (c1.G - c2.G)
                           + (c1.B - c2.B) * (c1.B - c2.B));
}

public class DuluxColour
{
    public string ColourName { get; set; }
    public Color Colour { get; set; }
}

Upvotes: 2

Views: 414

Answers (4)

TsunamiCoder
TsunamiCoder

Reputation: 120

you can still do,    

  public static void Main(string[] args)
        {
            //Your code goes here
            Console.WriteLine("Hello, world!");
            List<DuluxColour> _colors= new List<DuluxColour>();
            _colors.Add(new DuluxColour{Colour = Color.Black , ColourName ="Black"});
                _colors.Add(new DuluxColour{Colour = Color.Red , ColourName ="Red"});
                _colors.Add(new DuluxColour{Colour = Color.Green , ColourName ="Green"});
                _colors.Add(new DuluxColour{Colour = Color.Yellow , ColourName ="Yellow"});
            var col =ClosestColor(_colors, Color.Purple);
            Console.Write(col);
        }
        public static string ClosestColor(List<DuluxColour> colours, Color target)
        {

            var colorDiffs = colours.Select(n => ColorDiff(n.Colour, target)).Min(n => n);
            return colours.FirstOrDefault(n => ColorDiff(n.Colour, target) == colorDiffs).ColourName;
        }

        public static int ColorDiff(Color c1, Color c2)
        {
            return (int)Math.Sqrt((c1.R - c2.R) * (c1.R - c2.R)
                                   + (c1.G - c2.G) * (c1.G - c2.G)

Upvotes: -1

TsunamiCoder
TsunamiCoder

Reputation: 120

     public class Program
        {
            public static void Main(string[] args)
            {
                //Your code goes here
                Console.WriteLine("Hello, world!");
                List<DuluxColour> _colors= new List<DuluxColour>();
                _colors.Add(new DuluxColour{Colour = Color.Black , ColourName ="Black"});
                    _colors.Add(new DuluxColour{Colour = Color.Red , ColourName ="Red"});
                    _colors.Add(new DuluxColour{Colour = Color.Green , ColourName ="Green"});
                    _colors.Add(new DuluxColour{Colour = Color.Yellow , ColourName ="Yellow"});
                var col =ClosestColor(_colors, Color.Purple);
                Console.Write(col.ColourName);
            }
            public static DuluxColour ClosestColor(List<DuluxColour> colours, Color target)
            {

                var colorDiffs = colours.Select(n => ColorDiff(n.Colour, target)).Min(n => n);
                return colours.Find(n => ColorDiff(n.Colour, target) == colorDiffs);
            }

            public static int ColorDiff(Color c1, Color c2)
            {
                return (int)Math.Sqrt((c1.R - c2.R) * (c1.R - c2.R)
                                       + (c1.G - c2.G) * (c1.G - c2.G)
                                       + (c1.B - c2.B) * (c1.B - c2.B));
            }


        }


  public class DuluxColour
        {
            public string ColourName { get; set; }
            public Color Colour { get; set; }
        }

Upvotes: -1

Ilian
Ilian

Reputation: 5355

Try this:

public DuluxColour ClosestColor(List<DuluxColour> colours, Color target)
{
    var colorDiffs = colours.Select(n => ColorDiff(n.Colour, target)).Min(n => n);
    return colours.Find(n => ColorDiff(n.Colour, target) == colorDiffs);
}

Note that I chose to return DuluxColour instead of just the name so callers have the option to get the color value. In your case you will need to call:

string closestColorName = ClosestColor(colours, target).ColourName;

Take note that you have the handle the possibility of ClosestColor returning null.

Without using an explicit List, you can also use:

public DuluxColour ClosestColor(IEnumerable<DuluxColour> colours, Color target)
{
    var colorDiffs = colours.Select(n => ColorDiff(n.Colour, target)).Min(n => n);
    return colours.FirstOrDefault(n => ColorDiff(n.Colour, target) == colorDiffs);
}

Upvotes: 4

Ashwin
Ashwin

Reputation: 441

You May Try this,

public int ClosestColor(List<DuluxColour> colours, Color target)
    {

        var colorDiffs = colours.Select(n => ColorDiff(n.Colour, target)).Min(n => n);
        return colours.FindIndex(n => ColorDiff(n.Colour, target) == colorDiffs);
    }

I hope this may work for you

Upvotes: -1

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