How long value convert into ARGB color?

Question

public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{ 
    string userColourString = value.ToString();
    Debug.WriteLine(userColourString);
    long userColourNumeric = 0; 
    Int64.TryParse(userColourString, out userColourNumeric); 
    var colourToUse = userColourNumeric;
    return (Color)ColorConverter.ConvertFromString(string.Format("#{0:x6}", colourToUse));
}

I'm trying to convert the following two values into colours by using the converter method above but it's not working,. -2147483630 16777215

Answer 1

The value 16777215 decimal converts to FFFFFF hexadecimal. I tested your code, and the value of colourToUse is indeed "#ffffff". That will easily convert to the color White.

The value -2147483630 decimal ends up being converted to FFFFFFFF80000012 hexadecimal. I'm not sure what color you're hoping that'll convert to. No wonder the ConvertFromString method throws a format exception.

---

You added that you're referencing an old chart of VB6 color constants.

In order to generate the colors in that chart, you'll need to use ColorTranslator.FromWin32:

public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
    var userColourString = value.ToString();
    int userColourNumeric = 0;
    int.TryParse(userColourString, out userColourNumeric);
    var colourToUse = userColourNumeric;
    return ColorTranslator.FromWin32(colourToUse);
}