public static Color FromName(string name)
{
// try to get a known color first
Color color;
if (ColorTable.TryGetNamedColor(name, out color))
{
return(color);
}
// otherwise treat it as a named color
return(new Color(NotDefinedValue, StateNameValid, name, (KnownColor)0));
}
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
string strValue = value as string;
if (strValue != null)
{
string text = strValue.Trim();
if (text.Length == 0)
{
return(Color.Empty);
}
{
Color c;
// First, check to see if this is a standard name.
//
if (ColorTable.TryGetNamedColor(text, out c))
{
return(c);
}
}
if (culture == null)
{
culture = CultureInfo.CurrentCulture;
}
char sep = culture.TextInfo.ListSeparator[0];
TypeConverter intConverter = TypeDescriptor.GetConverter(typeof(int));
// If the value is a 6 digit hex number only, then
// we want to treat the Alpha as 255, not 0
//
if (text.IndexOf(sep) == -1)
{
// text can be '' (empty quoted string)
if (text.Length >= 2 && (text[0] == '\'' || text[0] == '"') && text[0] == text[text.Length - 1])
{
// In quotes means a named value
string colorName = text.Substring(1, text.Length - 2);
return(Color.FromName(colorName));
}
else if ((text.Length == 7 && text[0] == '#') ||
(text.Length == 8 && (text.StartsWith("0x") || text.StartsWith("0X"))) ||
(text.Length == 8 && (text.StartsWith("&h") || text.StartsWith("&H"))))
{
// Note: ConvertFromString will raise exception if value cannot be converted.
return(PossibleKnownColor(Color.FromArgb(unchecked ((int)(0xFF000000 | (uint)(int)intConverter.ConvertFromString(context, culture, text))))));
}
}
// Nope. Parse the RGBA from the text.
//
string[] tokens = text.Split(sep);
int[] values = new int[tokens.Length];
for (int i = 0; i < values.Length; i++)
{
values[i] = unchecked ((int)intConverter.ConvertFromString(context, culture, tokens[i]));
}
// We should now have a number of parsed integer values.
// We support 1, 3, or 4 arguments:
//
// 1 -- full ARGB encoded
// 3 -- RGB
// 4 -- ARGB
//
switch (values.Length)
{
case 1:
return(PossibleKnownColor(Color.FromArgb(values[0])));
case 3:
return(PossibleKnownColor(Color.FromArgb(values[0], values[1], values[2])));
case 4:
return(PossibleKnownColor(Color.FromArgb(values[0], values[1], values[2], values[3])));
}
throw new ArgumentException($"InvalidColor: {text}");
}
return(base.ConvertFrom(context, culture, value));
}
