[WPF] GradientStopCollection 의 Offset 컬러 구하기

Gradient 를 파랑(0) 초록(0.5) 노랑(1) 으로 표현을 한 경우

% 에 따른 색상을 구할때 사용한다.

 

#region GetColorByOffset(double)         /// <summary>         /// Gradient 색의 offset 값을 구합니다.         /// </summary>         /// <param name="offset"></param>         /// <returns></returns>         private Color GetColorByOffset(double offset)         {             GradientStopCollection collection = new GradientStopCollection(3);             collection.Add(new GradientStop(Colors.Blue, 0));             collection.Add(new GradientStop(Colors.Green, 0.5));             collection.Add(new GradientStop(Colors.Yellow, 1));               GradientStop[] stops = collection.OrderBy(x => x.Offset).ToArray();             if (offset <= 0) return stops[0].Color;             if (offset >= 1) return stops[stops.Length - 1].Color;             GradientStop left = stops[0], right = null;             foreach (GradientStop stop in stops)             {                 if (stop.Offset >= offset)                 {                     right = stop;                     break;                 }                 left = stop;             }               //Debug.Assert(right != null);             offset = Math.Round((offset - left.Offset) / (right.Offset - left.Offset), 2);             byte a = (byte)((right.Color.A - left.Color.A) * offset + left.Color.A);             byte r = (byte)((right.Color.R - left.Color.R) * offset + left.Color.R);             byte g = (byte)((right.Color.G - left.Color.G) * offset + left.Color.G);             byte b = (byte)((right.Color.B - left.Color.B) * offset + left.Color.B);             return Color.FromArgb(a, r, g, b);         }         #endregion