Loading a CSV Filles data into a TreeView

[DanielBarnes1]

I have a CSV file with Hierarchal Data in it which I wish to display in a TreeView.

Each entry in the file has a key which links it to a Parent.

For example one Entry might have the Key D1 so I no that has to go under the parent which has the code D1

I have set up my own NodeKey property which stores the code

The problem is when I find the code which matches the NodeKey property I don't no how to add a new entry under The parent or child heading.

The following code is how I have tried to do it.


'Loops round the nodes within the treeview
If (cNode.NodeKey = nextParent) Then
sString = nextElement & " " & nextDesc
iRecord = cNode.Index

Try
Nextmode = TreeView1.Nodes(iRecord)

Nextmode.Nodes.Add(New HalcrowTreeNode(sString, nextElement))

Does anybody have any ideas PLEASE. It been cause me a great Headache.

Thanks

Daniel

[Mike Hildner]

Do you have a sample csv file?

[Pirate]

Originally posted by Mike Hildner
Do you have a sample csv file?

You can get one anytime from System Tools ---->Event Viewer

[DanielBarnes1]

Heres an example CSV File in a zip file

[<ABX]

The only way i can see of doing this would be recursion

Edit: Threwup a little example for you...

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim Data As HalcrowNodeCollection = LoadCollection("..\UniclassBasic.csv")
 
        Dim Node As HalcrowTreeNode = SortNodes(Data)
 
        Dim aTreeNode As TreeNode = StartConvert(Node)
 
        TreeView1.Nodes.Add(aTreeNode)
 
    End Sub
 
    Private Function StartConvert(ByVal Node As HalcrowTreeNode) As TreeNode
        Dim rtn As New TreeNode
 
        rtn.Text = Node.Text
        rtn.Tag = Node.Key
 
        ConvertNode(rtn, Node)
 
        Return rtn
 
    End Function
 
    Private Function ConvertNode(ByRef aTreeNode As TreeNode, ByVal aHalcrowNode As HalcrowTreeNode)
 
        For Each n As HalcrowTreeNode In aHalcrowNode.MyNodes
            Dim newNode As New TreeNode
 
            newNode.Text = n.Text
            newNode.Tag = n.Key
            ConvertNode(newNode, n)
            aTreeNode.Nodes.Add(newNode)
        Next
 
    End Function
 
    Private Function LoadCollection(ByVal strFilePath As String) As HalcrowNodeCollection
 
        Dim RawData As New HalcrowNodeCollection
 
        Dim sr As New IO.StreamReader(strFilePath)
 
        Dim strFile() As String = Split(sr.ReadToEnd, vbCrLf)
        sr.Close()
 
        For I As Integer = 0 To strFile.Length - 1
            Dim strTmp() As String = Split(strFile(I), ",")
 
            If strTmp.Length = 3 Then
                RawData.Add(New HalcrowTreeNode(strTmp(1), strTmp(0), strTmp(2)))
            End If
 
        Next
 
        Return RawData
 
    End Function
 
    Public Function SortNodes(ByVal Nodes As HalcrowNodeCollection) As HalcrowTreeNode
        'Returns The Sorted Main Nodes of the Collection
 
        Dim MainNode As New HalcrowTreeNode("Uniclass", "Uniclass", "") ' main Node has no Parent
 
        GetChildNodes(MainNode, Nodes)
 
        Return MainNode
 
    End Function
 
    Private Function GetChildNodes(ByRef ParentNode As HalcrowTreeNode, ByRef Nodes As HalcrowNodeCollection)
 
        For I As Integer = 0 To Nodes.Count - 1
 
            If ParentNode.Key = Nodes.Item(I).ParentKey Then
                GetChildNodes(Nodes.Item(I), Nodes)
                ParentNode.MyNodes.Add(Nodes.Item(I))
            End If
 
        Next
    End Function

Option Explicit On 
 
Public Class HalcrowTreeNode
 
    Private m_strText As String
    Private m_strKey As String
    Private m_strParentKey As String
    Private m_MyNodes As New HalcrowNodeCollection
 
 
    Public Property Text() As String
        Get
            Return m_strText
        End Get
        Set(ByVal Value As String)
            m_strText = Value
        End Set
    End Property
 
    Public Property Key() As String
        Get
            Return m_strKey
        End Get
        Set(ByVal Value As String)
            m_strKey = Value
        End Set
    End Property
 
    Public Property ParentKey() As String
        Get
            Return m_strParentKey
        End Get
        Set(ByVal Value As String)
            m_strParentKey = Value
        End Set
    End Property
 
    Public Sub New(ByVal strText As String, ByVal strKey As String, ByVal strParentKey As String)
        m_strText = strText
        m_strKey = strKey
        m_strParentKey = strParentKey
    End Sub
 
    Public Sub New(ByVal strText As String, ByVal strKey As String, ByVal strParentKey As String, ByVal MyNodes As HalcrowNodeCollection)
 
    End Sub
 
    Public Property MyNodes() As HalcrowNodeCollection
        Get
            Return m_MyNodes
        End Get
        Set(ByVal Value As HalcrowNodeCollection)
            m_MyNodes = Value
        End Set
    End Property
End Class
 
Public Class HalcrowNodeCollection
    Inherits CollectionBase
 
    ' Restricts to HalcrowTreeNode types, items that can be added to the collection.
    Public Sub Add(ByVal aHalcrowTreeNode As HalcrowTreeNode)
        ' Invokes Add method of the List object to add a HalcrowTreeNode.
        List.Add(aHalcrowTreeNode)
    End Sub
 
    ' Visual Basic
    Public Sub Remove(ByVal index As Integer)
        ' Check to see if there is a HalcrowTreeNode at the supplied index.
        If index > Count - 1 Or index < 0 Then
            ' If no HalcrowTreeNode exists, a messagebox is shown and the operation is 
            ' cancelled.
            System.Windows.Forms.MessageBox.Show("Index not valid!")
        Else
            ' Invokes the RemoveAt method of the List object.
            List.RemoveAt(index)
        End If
    End Sub
 
    ' This line declares the Item property as ReadOnly, and 
    ' declares that it will return a HalcrowTreeNode object.
    Public ReadOnly Property Item(ByVal index As Integer) As HalcrowTreeNode
        Get
            ' The appropriate item is retrieved from the List object and 
            ' explicitly cast to the HalcrowTreeNode type, then returned to the 
            ' caller.
            Return CType(List.Item(index), HalcrowTreeNode)
        End Get
    End Property
 
End Class