Reading a file in and outputting to two listboxes - vb.net

Question

I'm using Imports System.IO and StreamReader inside a Windows Forms App.
I am trying to take a file, read it in, and output it into two listboxes. The text file is formatted like this.
Blue, 23.7
Green, 60.1
Black, 45.3
I want to output colours that have a higher value than 50 into one listbox, and the ones lower into another. So far all I've done is output the whole list into a textbox. The code for that looks like this:
srTextFile = File.OpenText(dataFile)
Do While srTextFile.EndOfStream = False
'read file by line, use the comma as a splitter
thisFile = srTextFile.ReadLine().Split(",")
For i As Integer = 0 To thisFile.GetUpperBound(0)
txtFileDisplay.AppendText(thisFile(i) &vbTab)
Next
txtFileDisplay.AppendText(vbCrLf)
Loop
I'm completely new to reading in files. I really don't know what I'm doing. I'm pretty new to arrays as well.
Thanks!

Answer 1

By using a class, you can create objects containing the color names as well as the double value and add those to the listboxes.
Public Class ColorValue
Public Property Name As String
Public Property Value As Double
Public Overrides Function ToString() As String
Return $"{Name} ({Value})"
End Function
End Class
Note that I've overridden ToString, because ListBox uses it to display a text for each item.
Now, you can add colors to the listboxes like this
For Each line As String In File.ReadLines(dataFile)
Dim parts As String() = line.Split(","c)
If parts.Length = 2 Then 'If line is well-shaped.
Dim value As Double
Double.TryParse(Trim(parts(1)), value) 'Gets 0 into value if conversion fails.
Dim color = New ColorValue With {.Name = parts(0), .Value = value}
If value > 50.0 Then
listBox1.Items.Add(color)
Else
listBox2.Items.Add(color)
End If
End If
Next
Now, you can get a color value back with
Dim c As ColorValue = DirectCast(listBox1.SelectedItem, ColorValue)
Dim n As String = c.Name
Dim v As Double = c.Value

Answer 2

You can make use of the System.IO.File Class to do this
Simply read the text file into a string
Split the string into lines
Split the lines into arrays
Parse the strings into doubles
Compare the doubles and get values greater than 50 into a seperate listbox
You can write your code like this:
For Each line As String In File.ReadAllLines("Your file here")
Dim Spl() AS String = Split(line, ",")
'Convert string value to integer
Dim myNum As Double = Double.Parse(Spl(1))'The number is the second item in the array
If myNum < 50.0 Then
'Add to your first Listbox here using
'Listbox.Add(myNum)
Else
'Add to your second Listbox here using
'Listbox.Add(myNum)
End If
Next