Question

Hallo everbody,

if for example I set the BackColor of a Panel in Winform using Visual Studio, I can pick up the color from 3 lists:

Custom, Web, System

Is it possible to retreive only the Web colors in my C# code application? They are part of KnownColor but so far I could only find how to eliminate System Control from my list.

I would like to use the web colors because they are sorted in a nice way and I would like to insert them into a self-implemented combobox.

Thank you

Answer 1

Color struct contains all the web colors as constants (system colors are defined as constants in SystemColors class)

To get a list of these colors just do:

var webColors = GetConstants(typeof(Color));
var sysColors = GetConstants(typeof(SystemColors));

having GetConstants defined as follow:

static List<Color> GetConstants(Type enumType)
{
    MethodAttributes attributes = MethodAttributes.Static | MethodAttributes.Public;
    PropertyInfo[] properties = enumType.GetProperties();
    List<Color> list = new List<Color>();
    for (int i = 0; i < properties.Length; i++)
    {
        PropertyInfo info = properties[i];
        if (info.PropertyType == typeof(Color))
        {
            MethodInfo getMethod = info.GetGetMethod();
            if ((getMethod != null) && ((getMethod.Attributes & attributes) == attributes))
            {
                object[] index = null;
                list.Add((Color)info.GetValue(null, index));
            }
        }
    }
    return list;
}

---

EDIT:

To get colors sorted exactly like in VS do:

var webColors = GetConstants(typeof(Color));
var sysColors = GetConstants(typeof(SystemColors));

webColors.Sort(new StandardColorComparer());
sysColors.Sort(new SystemColorComparer());

with StandardColorComparer and SystemColorComparer defined as follows:

class StandardColorComparer : IComparer<Color>
{
    // Methods
    public int Compare(Color color, Color color2)
    {
        if (color.A < color2.A)
        {
            return -1;
        }
        if (color.A > color2.A)
        {
            return 1;
        }
        if (color.GetHue() < color2.GetHue())
        {
            return -1;
        }
        if (color.GetHue() > color2.GetHue())
        {
            return 1;
        }
        if (color.GetSaturation() < color2.GetSaturation())
        {
            return -1;
        }
        if (color.GetSaturation() > color2.GetSaturation())
        {
            return 1;
        }
        if (color.GetBrightness() < color2.GetBrightness())
        {
            return -1;
        }
        if (color.GetBrightness() > color2.GetBrightness())
        {
            return 1;
        }
        return 0;
    }
}

class SystemColorComparer : IComparer<Color>
{
    // Methods
    public int Compare(Color color, Color color2)
    {
        return string.Compare(color.Name, color2.Name, false, CultureInfo.InvariantCulture);
    }
}

N.B. :

This code has been taken from System.Drawing.Design.ColorEditor through reflector.