Read and change combo-box selected item with 4 different possible values - vb.net

Question

I have a multi-line textbox that the user can type into; the contents of which are supposed to drive the currently selected item in a combobox.
I have existing code that works for two items currently (Yes & No); however, I now need to make this extend to supporting four items. This is also updated by a timer every 3 seconds, in case if the user manually updated the text. The combobox cannot be typed in, instead it has preset selections.
Also the program is designed to edit properties files.
I'm a little unsure on how to go about doing so.
This is what works for 2 item changes:
Dim lines as Textbox1.lines()
Dim ach_tr As String = "announce-player-achievements=" 'stuff to be replaced by string ach_ttr
Dim ach_ttr As String = "" 'empty string to delete string ach_tr
Dim ach As String = lines(My.Settings.AnnouncePlayerAchievements)'line of string ach_tr
ach = ach.Replace(ach_tr, ach_ttr)'removes string ach_tr and leaves the value
If ach = "true" Then
achievements.SelectedItem = "Yes"
Else
achievements.SelectedItem = "No"
End If
I've tried these for 4 items:
Dim lines as Textbox1.lines()
Dim diff_tr As String = "difficulty="
Dim diff_ttr As String = ""
Dim diff As String = lines(My.Settings.Difficulty)
diff = diff.Replace(diff_tr, diff_ttr)
If diff = "0" Then
achievements.SelectedItem = "Peaceful"
End If
If diff = "1" Then
achievements.SelectedItem = "Easy"
End If
If diff = "2" Then
achievements.SelectedItem = "Normal"
End If
If diff = "3" Then
achievements.SelectedItem = "Hard"
End If
And This one:
Dim lines as Textbox1.lines()
Dim diff_tr As String = "difficulty="
Dim diff_ttr As String = ""
Dim diff As String = lines(My.Settings.Difficulty)
diff = diff.Replace(diff_tr, diff_ttr)
If diff = "0" Then
achievements.SelectedItem = "Peaceful"
Else
If diff = "1" Then
achievements.SelectedItem = "Easy"
Else
If diff = "2" Then
achievements.SelectedItem = "Normal"
Else
If diff = "3" Then
achievements.SelectedItem = "Hard"
End If
End If
End If
End If

Answer 1

You could do something akin to:
var difficultyMap = new Dictionary<string,string>
{
{"0", "Peaceful"},
{"1", "Easy"},
{"2", "Normal"},
{"3", "Hard"}
};
difficultyCombo.Items = difficultyMap.Values;
updateTimer.Tick += (s,e) => {
var text = inputTextBox.Text;
string found;
if (!difficultyMap.TryGetValue(text))
{
MessageBox.Show("unknown difficulty");
return;
}
difficultyCombo.SelectedItem = found;
};
This is in C# as I don't know VB very well, but the core concepts should map, I'm also not sure of your exact implementation or requirements, in essence I've done the following:
Created a dictionary that goes from the "numeric" difficulty type to the display type for the combo
Populated the combo using the display values from the dictionary
Whenever the update timer fires, I:
Get the text from the textbox
Try to find the matching difficulty in the dictionary
Display an error or update the combo
Adding n number of items to the combo and text input is trivial now, as you just add a new entry to the dictionary.

Answer 2

Edit: For future reference Heres a more compact version which works as well:
Public LineNum As Globals.LineNumEnum
Dim serveriptr As String = ("server-ip=")
Dim sipc As String = PropView.OutputRTF.Lines(LineNum.SerIP)
sipc = sipc.Replace(serveriptr, Nothing)
I found my problem. I was trying to change the wrong combobox lol. well at least I learned about dictionaries and the select case. Well thanks for your time.
This is the correct code lol:
Dim diff_tr As String = "difficulty="
Dim diff_ttr As String = ""
Dim diff As String = lines(My.Settings.Difficulty)
diff = diff.Replace(diff_tr, diff_ttr)
If diff = "0" Then
difficulty.SelectedItem = "Easy"
ElseIf diff = "1" Then
difficulty.SelectedItem = "Easy"
ElseIf diff = "2" Then
difficulty.SelectedItem = "Normal"
ElseIf diff = "3" Then
difficulty.SelectedItem = "Hard"
End If