从RGB到Long到RGB

Question

如何将Red, Green, Blue值转换为Long，并在C#中正确地返回到Red, Green, Blue？

我到处找遍了，找不到有用的东西。

Answer 1

    public enum ColorFormat
    {
        RGB, RGBA, ARGB
    }

    public static int ColorToDecimal(Color color, ColorFormat format = ColorFormat.RGB)
    {
        switch (format)
        {
            default:
            case ColorFormat.RGB:
                return color.R << 16 | color.G << 8 | color.B;
            case ColorFormat.RGBA:
                return color.R << 24 | color.G << 16 | color.B << 8 | color.A;
            case ColorFormat.ARGB:
                return color.A << 24 | color.R << 16 | color.G << 8 | color.B;
        }
    }

    public static Color DecimalToColor(int dec, ColorFormat format = ColorFormat.RGB)
    {
        switch (format)
        {
            default:
            case ColorFormat.RGB:
                return Color.FromArgb((dec >> 16) & 0xFF, (dec >> 8) & 0xFF, dec & 0xFF);
            case ColorFormat.RGBA:
                return Color.FromArgb(dec & 0xFF, (dec >> 24) & 0xFF, (dec >> 16) & 0xFF, (dec >> 8) & 0xFF);
            case ColorFormat.ARGB:
                return Color.FromArgb((dec >> 24) & 0xFF, (dec >> 16) & 0xFF, (dec >> 8) & 0xFF, dec & 0xFF);
        }
    }

Answer 2

   Color c = Color.FromArgb(30, 20, 120); // construct a color from RGB values
   long  redVal = c.R; //Extract Red value as long
   long greenVal = c.G;//Extract Green Value as Long
   long blueVal = c.B;//Extract Blue Value as Long

您还可以如下所示声明颜色：

 Color c = Color.Beige;

然后是c.R=245，c.G=245，c.B=220