C# Signature:

[System.Runtime.InteropServices.DllImport("shlwapi.dll")]
static extern void ColorRGBToHLS(int RGB, ref int H, ref int L, ref int S);

VB.Net Signature:

<System.Runtime.InteropServices.DllImport("shlwapi.dll", EntryPoint:="ColorRGBToHLSW", SetLastError:=True, CharSet:=System.Runtime.InteropServices.CharSet.Unicode)>
Private Shared Sub ColorRGBToHLS(RGB As Integer, ByRef H As Integer, ByRef L As Integer, ByRef S As Integer)
End Sub

User-Defined Types:

None.

Alternative Managed API:

Do you know one? Please contribute it!

Notes:

None.

Tips & Tricks:

Please add some!

In VB .NET you can get the H, S, and B or L values from then color structure:

'B, Brightness, a.k.a L Lightness, Luminance

DIM red as Color = Color.FromArbg(255,255,0,0)

DIM H, S, B As Single

H = red.GetHue

S = red.GetSaturation

B = red.GetBrightness

Sample Code:

  using System;
  using System.Drawing;
  using System.Runtime.InteropServices;
  sealed class Win32
  {
    [DllImport("shlwapi.dll")]
    static extern void ColorRGBToHLS(int RGB, ref int H, ref int L, ref int S);

    //
    //Convert System.Drawing.Color structure to HLS.
    //
    static public void ColorToHLS(System.Drawing.Color C,ref int H,ref int L,ref int S)
    {
      //
      //Use ColorTranslator.ToWin32 rather than Color.ToArgb because we need 0x00BBGGRR,
      //which is returned by ToWin32, rather than 0x00RRGGBB, which is returned by ToArgb.
      //
      ColorRGBToHLS(ColorTranslator.ToWin32(C), ref H, ref L, ref S);
    }
  }