Re: Treeview - Check all Child Nodes on checking parent node

[ForumAccount]

If you follow a pattern similar to what I've done below, you will get the desired result. And yes, you should be doing this before you add the nodes. Not adding the nodes and then rearranging them.

Public Class Form1

    '//fields
    Private md5Dictionary As New Dictionary(Of String, TreeNode)()

    '//event handlers
    Private Sub Button1_Click(ByVal sender As System.Object, _
                              ByVal e As System.EventArgs) Handles Button1.Click

        '//lets say these are some of the hashes (two duplicates)
        Dim hashes = New String() {"[E886B7DEA0BE6AA0CB34F623924A3AD2]", _
                                   "[AS823N239XM29323RKJ2H3K23KD2K3SS]", _
                                   "[KJH23KH2K3T239829829230H23KK3H2K]", _
                                   "[E886B7DEA0BE6AA0CB34F623924A3AD2]"}

        '//lets say that these 4 files correspond to the above 4 hashes
        Dim files = New String() {"C:\test\file.txt", _
                                  "C:\Program Files\system.dll", _
                                  "C:\test\source.xml", _
                                  "C:\test\file - Copy.txt"}


        Dim fileIndex = 0
        For Each hash In hashes

            '//check in your dictionary if the hash has already been added
            If Me.md5Dictionary.ContainsKey(hash) Then

                '//we've already seen this hash
                Me.md5Dictionary(hash).Nodes.Add(files(fileIndex))
            Else

                '//haven't encountered this hash yet
                Dim node = Me.TreeView1.Nodes.Add(hash)

                '//add the actual file value to the hash node
                node.Nodes.Add(files(fileIndex))

                '//add a new dictionary entry
                Me.md5Dictionary.Add(hash, node)
            End If
            fileIndex += 1
        Next

        Me.TreeView1.ExpandAll()
    End Sub

End Class

Output: