Populating a combo box with a list of functions - Need Advice - vb.net

Question

I'm looking for some advice on the best way to handle this.
I have a list of about 200 "Functions" which are listed in a combo box. When the user selects a 'function' from the list, I need to return the functionID (integer).
I know this can be done easily by binding a dataset to the key and value of the combobox, I'm just not sure about the best way to populate the dataset.
I feel that the way I'm doing it currently is very convoluted:
I currently have a txt file as an embedded resource which I write to a temporary directory, then I use the following code to read in that text file and populate that box by setting the combobox's datasource and Display Member. It does this by way of a custom class which is implementing System.Collections.IList.
I have pasted the code below. The reason I want to simplify it is that I dislike writing the text file to the disk, because sometimes it fails.
I'm looking for a way to populate my combobox and return my ID, without writing anything to the user's temp folder.
I am open to changing the format of the embedded resource, and or the code.
The fnlist.txt is formatted currently as follows.
index, Function Name, ID
The index is only included for sorting (to keep NONE at the bottom, and unknown function at the top), and I suppose is not strictly required.
#Region "Function lookup"
Dim path As String = System.IO.Path.GetTempPath
Dim _objFnXtef As New clsFunctionXref(path & "fnList.txt")
Private Sub populate_list()
functionlist.DataSource = _objFnXtef
functionlist.DisplayMember = "StrFunction"
End Sub 'Populates the function list
Function get_index(ByVal fnid As Integer)
Dim iLookupNumber As Integer = fnid
Dim tmpFnInfo As New clsFunctionInfo
Dim iReturnIdx As Integer = -1
If iLookupNumber <> 0 Then
tmpFnInfo.IFunctionNumber = iLookupNumber
iReturnIdx = _objFnXtef.IndexOf(tmpFnInfo)
If iReturnIdx <> -1 Then
Return iReturnIdx - 1
Else
Return get_index(9999)
End If
End If
Return 0
End Function 'Returns index of specified function number
#End Region 'All function list functions
Here is the code when a user changes the drop down:
Private Sub functionlist_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles functionlist.SelectedIndexChanged
Dim iReturnFuctionID As Integer = 0
Dim tmpFnInfo As New clsFunctionInfo
tmpFnInfo = _objFnXtef(functionlist.SelectedIndex)
iReturnFuctionID = tmpFnInfo.IFunctionNumber
Func = (iReturnFuctionID)
End Sub
And here is the supporting class:
Imports Microsoft.VisualBasic.FileIO
Public Class clsFunctionInfo
Private _idxFunction As Integer
Public Property IdxFunction() As Integer
Get
Return _idxFunction
End Get
Set(ByVal value As Integer)
_idxFunction = value
End Set
End Property
Private _strFunction As String
Public Property StrFunction() As String
Get
Return _strFunction
End Get
Set(ByVal value As String)
_strFunction = value
End Set
End Property
Private _iFunctionNumber As Integer
Public Property IFunctionNumber() As Integer
Get
Return _iFunctionNumber
End Get
Set(ByVal value As Integer)
_iFunctionNumber = value
End Set
End Property
End Class
Public Class clsFunctionXref
Implements System.Collections.IList
Private _colFunctionInfo As New Collection
Private _filePath As String
Public Property FilePath() As String
Get
Return _filePath
End Get
Set(ByVal value As String)
_filePath = value
End Set
End Property
Public Sub New(ByVal filename As String)
_filePath = filename
Dim _idx As Integer = 1
Dim fields As String()
Dim delimiter As String = ","
Dim iFnx As Integer
Using parser As New TextFieldParser(filename)
parser.SetDelimiters(delimiter)
While Not parser.EndOfData
' Read in the fields for the current line
fields = parser.ReadFields()
Try
iFnx = Convert.ToInt16(fields(0).ToString)
Catch ex As Exception
MessageBox.Show("Error reading file. " & ex.ToString, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
Exit Sub
End Try
Dim objFunction As New clsFunctionInfo
objFunction.IdxFunction = _idx
objFunction.IFunctionNumber = iFnx
objFunction.StrFunction = fields(1).ToString
Me.Add(objFunction)
_idx += 1
End While
End Using
End Sub
Public Function Add(ByVal value As Object) As Integer Implements System.Collections.IList.Add
If _colFunctionInfo.Contains(value.IFunctionNumber.ToString) Then
SyncLock Me.SyncRoot
_colFunctionInfo.Remove(value.IFunctionNumber.ToString)
End SyncLock
ReIndex()
End If
SyncLock Me.SyncRoot
_colFunctionInfo.Add(value, value.IFunctionNumber.ToString)
End SyncLock
End Function
Public Sub Clear() Implements System.Collections.IList.Clear
SyncLock Me.SyncRoot
_colFunctionInfo.Clear()
End SyncLock
End Sub
Public Function Contains(ByVal value As Object) As Boolean Implements System.Collections.IList.Contains
If _colFunctionInfo.Contains(value.IFunctionNumber.ToString) Then
Return True
Else
Return False
End If
End Function
Public ReadOnly Property Count() As Integer Implements System.Collections.ICollection.Count
Get
Return _colFunctionInfo.Count
End Get
End Property
Public ReadOnly Property IsReadOnly() As Boolean Implements System.Collections.IList.IsReadOnly
Get
Return False
End Get
End Property
Public Sub Remove(ByVal value As Object) Implements System.Collections.IList.Remove
If _colFunctionInfo.Contains(value.IFunctionNumber.ToString) Then
SyncLock Me.SyncRoot
_colFunctionInfo.Remove(value.IFunctionNumber.ToString)
End SyncLock
ReIndex()
End If
End Sub
Public Function GetEnumerator() As System.Collections.IEnumerator Implements System.Collections.IEnumerable.GetEnumerator
Return _colFunctionInfo.GetEnumerator
End Function
Public Sub Insert(ByVal index As Integer, ByVal value As Object) Implements System.Collections.IList.Insert
SyncLock Me.SyncRoot
If _colFunctionInfo.Contains(value.IFunctionNumber.ToString) Then
_colFunctionInfo.Remove(value.IFunctionNumber.ToString)
End If
If index < _colFunctionInfo.Count Then
_colFunctionInfo.Add(value, value.IFunctionNumber.ToString, index - 1)
Else
_colFunctionInfo.Add(value, value.IFunctionNumber.ToString)
End If
End SyncLock
ReIndex()
End Sub
Public Sub RemoveAt(ByVal index As Integer) Implements System.Collections.IList.RemoveAt
SyncLock Me.SyncRoot
If _colFunctionInfo.Count <= index And index > 0 Then
_colFunctionInfo.Remove(index)
End If
End SyncLock
ReIndex()
End Sub
Private Sub ReIndex()
SyncLock Me.SyncRoot
Dim iReIndex As Integer = 1
Dim colTemp As New Collection
For Each obj As clsFunctionInfo In _colFunctionInfo
obj.IdxFunction = iReIndex
colTemp.Add(obj, obj.IFunctionNumber)
iReIndex += 1
Next
_colFunctionInfo.Clear()
For Each obj1 As clsFunctionInfo In colTemp
_colFunctionInfo.Add(obj1, obj1.IFunctionNumber.ToString)
Next
colTemp.Clear()
End SyncLock
End Sub
Public ReadOnly Property IsSynchronized() As Boolean Implements System.Collections.ICollection.IsSynchronized
Get
Return True
End Get
End Property
Public ReadOnly Property SyncRoot() As Object Implements System.Collections.ICollection.SyncRoot
Get
Dim _syncRoot As New Object
Return _syncRoot
End Get
End Property
Public ReadOnly Property IsFixedSize() As Boolean Implements System.Collections.IList.IsFixedSize
Get
Return False
End Get
End Property
Public Sub CopyTo(ByVal array As System.Array, ByVal index As Integer) Implements System.Collections.ICollection.CopyTo
For Each obj As clsFunctionInfo In _colFunctionInfo
array(index) = obj
index += 1
Next
End Sub
Public Function IndexOf(ByVal value As Object) As Integer Implements System.Collections.IList.IndexOf
SyncLock Me.SyncRoot
Dim tmpFnInfo As New clsFunctionInfo
Dim tmpFunctionNumber As Integer
Dim tmpidx As Integer = -1
tmpFnInfo = DirectCast(value, clsFunctionInfo)
tmpFunctionNumber = tmpFnInfo.IFunctionNumber
For Each obj In _colFunctionInfo
tmpFnInfo = DirectCast(obj, clsFunctionInfo)
If tmpFunctionNumber = tmpFnInfo.IFunctionNumber Then
tmpidx = tmpFnInfo.IdxFunction
Exit For
End If
Next
Return tmpidx
End SyncLock
End Function
Default Public Property Item(ByVal index As Integer) As Object Implements System.Collections.IList.Item
Get
index += 1
Return _colFunctionInfo(index)
End Get
Set(ByVal value As Object)
End Set
End Property
End Class
I'm sorry that this is so long, but I know that someone on here has some great suggestions on how to handle this because I'm having a little trouble wrapping my head around it. I think I've been starring at it too long.

Answer 1

since you have the text file as an embedded resource, you can open a stream to the file from there, without having to write it to disk. The ResourceReader class should help you.