To represent different density values, a color gradient is applied to the color bar, the basic method is to multiply the ARGB components by a gradient coefficient.
Below is the process of applying three gradient values to ten colors.
public void DrawRect(gasConcentration[] data) { Graphics graphic = pictureBox1.CreateGraphics(); Graphics graphic2 = pictureBox2.CreateGraphics(); int iCall2 = pictureBox2.Width/10; data = new gasConcentration[40]; int iLen = pictureBox1.Width = 540; int iHigh = pictureBox1.Height; //Initialize ten colors Color[] color = new Color[10] { Color.FromArgb(240, 0, 0), Color.Green, Color.Yellow, Color.Blue, Color.SteelBlue, Color.SeaGreen, Color.Chartreuse, Color.SaddleBrown, Color.Violet, Color.BurlyWood}; //Ten colors, each with three depths for (int i = 0; i < 40; i++) { data[i].gasType = i/4 + 1; data[i].gasConc = i%4; } Color c3, c4; if (data.Length > 0) { int iCall = iLen / data.Length; pictureBox2.Width = iCall * data.Length; pictureBox1.Width = iCall * data.Length; iCall2 = iCall * 4; // draw a comparison frame for (int i = 0; i < 10; i++) { Brush brush1 = new LinearGradientBrush(new Point(0, iHigh), new Point(iCall2, iHigh), color[i], color[i]); graphic2.FillRectangle(brush1, 0 + iCall2 * i, 0, iCall2, iHigh); brush1.Dispose(); } //Draw the color bar gradient component for (int i = 0; i < data.Length; i++) { // Divide the color into three depths if (data[i].gasConc != 0) c3 = c4 = Color.FromArgb((byte)(255 * (float)(1 - (data[i].gasConc * 0.01))), (byte)(color[data[i].gasType-1].R * (float)(1 - (data[i].gasConc * 0.2))), (byte)(color[data[i].gasType-1].G * (float)(1 - (data[i].gasConc * 0.2))), (byte)(color[data[i].gasType-1].B * (float)(1 - (data[i].gasConc * 0.2)))); else c3 = c4 = Color.Black; Brush brush1 = new LinearGradientBrush(new Point(0, iHigh), new Point(iCall, iHigh), c3, c4); graphic.FillRectangle(brush1, 0 + iCall * i , 0, iCall, iHigh); brush1.Dispose(); } } else { c4 = color[0]; Brush brush1 = new LinearGradientBrush(new Point(0, iHigh), new Point(iLen, iHigh), c4, c4); graphic.FillRectangle(brush1, 0, 0, iLen, iHigh); brush1.Dispose(); } }
public struct gasConcentration { int iGasType;//Gas name int iGasConc;//Gas concentration// 0=no, 1=low, 2=med, 3=high public int gasType { get { return iGasType; } set { iGasType = value; } } public int gasConc { get { return iGasConc; } set { iGasConc = value; } } }