Question

I got a console application that draws line in a 3D CAD program. Now to make this more clear i want to change these lines in different colors.

My code read variables from a text-file and calculates data from it and then makes a lines from this calculated data.
This process gets repeated with every line in the text file wich contains data.

Now i want visual basic to change the color everytinme a new line is drawn, so i get different colored lines.

I tried using a For.. To.. Step method, but this didnt work. I also tried to use the variables from my text file( these are different so when a new line got read the RGB code will change) but this will geve me only a lot of blue colors.

Any suggestions?

EDit:

This is what i use to draw the curves, the RGB code has to cahnge everytime when a line with new data is made:

' Creating a Curve2d object by using the above defined points
                    objLineString = objLineStrings.AddByPoints(PointCount:=points, points:=dataArray)
                    objGeometricStyle = objLineString.Style
                    color = objGeometricStyle.LinearColor
                    objGeometricStyle.LinearColor = RGB(0,0,0)

Answer 1

What about :

Dim rand As New Random() ' Used to generate random numbers
Dim colors(100) as Integer

' Create the colors
For i as Integer = 0 to 100 Step 1
    colors(i) = RGB(rand.Next(256), rand.Next(256), rand.Next(256))
Next

For i As Integer = 0 To 100 Step 1 ' Adjust to your needs
    ' Creating a Curve2d object by using the above defined points
    objLineString = objLineStrings.AddByPoints(PointCount:=points, points:=dataArray)
    objGeometricStyle = objLineString.Style
    color = objGeometricStyle.LinearColor
    objGeometricStyle.LinearColor = colors(i Mod 100) ' Mod returns the remainder of i / 100, so it's always less than 100.
Next

This won’t always give you “pretty” colors, but they’ll be different for each line. If you want control over the generated colors, you could set up an array of predefined colors and use these in your iteration.