Justify text according to a size as opposed to string length? ASP.NET - asp.net

Question

I have listbox with text in it, and I was asked to see if I could just justify its contents after the dash. My resulting code produced something like this:
Which works fine for scenarios where the text to the left of the dash is less than the max length found from the other items in the listbox (i.e. (B20) is less than (B15-B19), which is the longest entry found, so add some whitespace before the dash).
The issue, though, is that if the text before the dash is same length, it still looks like it isn't justified. Example:
Is there a way to truly line up all the dashes? I would imagine I would have to look at the actual pixel length of the characters before the dash as opposed to the length?
Notes:
I am using ASP.NET Webforms
VB.NET
The text for each item in the listbox is all one string
Right now, my method to accomplish what you see in the first picture is as follows:
Public Sub JustifyDisplayName()
Const ACCOUNT_FOR_DASH As Integer = 4
Dim maxCharCount As Integer = 0
Dim whiteSpace As String = HttpUtility.HtmlDecode(" ")
'Find which one is the longest code
For Each element As TextEntry In Me
If element.Value.Length > maxCharCount Then
maxCharCount = element.Value.Length
End If
Next
'Now, extend the '-' to the max for all items
For Each element As TextEntry In Me
'See how much white space we need to inject
Dim paddingNeeded As Integer = maxCharCount - element.Value.Length
Dim tempDisplay As StringBuilder = New StringBuilder(element.Value)
If paddingNeeded > 0 Then
tempDisplay.Append(CChar(whiteSpace), paddingNeeded + ACCOUNT_FOR_DASH)
tempDisplay.Append(" - " & element.Description)
End If
tempDisplay.Append(" - " & element.Description)
element.DrillDownDisplayNameJustified = tempDisplay.ToString()
Next
End Sub
Thanks.

Answer 1

If you used a fixed-width font, you could make this all much easier. In addition to good ol' Courier, I believe there are others.
If you don't, you're not going to be able to get exactly the right width. You could get close, but you won't get it exactly, because the difference in length between (H60-H95) and (I00-I99) as they are rendered may not evenly divide into increments of one .
But if you really want to give this a try, you'll have to use the System.Drawing namespace, the Graphics class, and a method on Graphics called MeasureString. This will be just to get the lengths of the strings in your selected font, though: System.Drawing doesn't apply to web apps.

Answer 2

If you could append spaces to short items before the dash so that you always have the same number of characters before the dash, you may consider using Monospaced Fonts, where each character occupies the same width - Ref: Similar Question.