How do I serialize a System.Windows.Media.Color object to an sRGB string?

Question

I need to serialize a color used in a WPF application to a database. I'd like to use the sRGB values, because they're more familiar to those of us that have spent the last few years doing web development.

How can a get an ARGB string (like #FFFFFFFF) from a System.Windows.Media.Color object?

UPDATE: I was misled by the documentation on MSDN. As @Kris noted below, the documentation for the ToString() method is incorrect. Although it says that ToString() "creates a string representation of the color using the ScRGB channels", it will actually return a string in ARGB hex format if the color was created using the FromARGB() method. It's an undocumented feature, I suppose.

See http://msdn.microsoft.com/en-us/library/ms606572.aspx

Answer 1

If you create your colors using either Color.FromRgb or Color.FromArgb instead of FromScRgb you should get a hex string result from ToString.

If you want to do it manually

string.Format("#{0:X2}{1:X2}{2:X2}{3:X2}", c.A, c.R, c.G, c.B);

You can use int.Parse(,NumberStyles.HexNumber) to go the other way.

Note sRGB and scRGB refer to different color spaces, make sure your using the one you want.

Answer 2

You can also do it this way:

string myHex = new ColorConverter().ConvertToString(myColor);

Answer 3

I created a struct to handle conversion and serialisation. It solves two problems for me: it is serialisable and it corrects the spelling ;)

[Serializable]
public struct Colour
    {
    public byte A;
    public byte R;
    public byte G;
    public byte B;

    public Colour(byte a, byte r, byte g, byte b)
        {
        A = a;
        R = r;
        G = g;
        B = b;
        }

    public Colour(Color color)
        : this(color.A, color.R, color.G, color.B)
        {
        }

    public static implicit operator Colour(Color color)
        {
        return new Colour(color);
        }

    public static implicit operator Color(Colour colour)
        {
        return Color.FromArgb(colour.A, colour.R, colour.G, colour.B);
        }
    }

Just use Colour where you would otherwise use System.Windows.Media.Color

Answer 4

If your purpose is to serialize to a file and deserialize back to the color object, I think you are better of to convert color to an Int32 and vice versa. It is no brainier to serialize/deserialize Int32. If this is your purpose, here is the code: Color To Int32:

        byte[] color = new byte[4];
        color[0] = Color.B;
        color[1] = Color.G;
        color[2] = Color.R;
        color[3] = Color.A;
        Int32 intColor = System.BitConverter.ToInt32(color, 0);

Int32 To Color:

byte[] bytes = System.BitConverter.GetBytes(intColor);
Color =new System.Windows.Media.Color(){B= bytes[0], G=bytes[1], R=bytes[2], A=bytes[3]};