How to search all nodes of TreeView ,TextBox With 'LINQ'

Question

hi

If the entered text is present in the content of the item, it will be colored.

    Dim MyDataTable As New DataTable
    Dim lstOfNodes As New List(Of TreeNode)
    Public dynamicColumn As String()
    Private Sub frmTreeView_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        MyDataTable.Columns.Add("Group")
        MyDataTable.Columns.Add("Type")
        MyDataTable.Columns.Add("Size")
        MyDataTable.Columns.Add("Location")
        MyDataTable.Rows.Add({"CABLE", "MV", "1x240", "Air Building"})
        MyDataTable.Rows.Add({"CABLE", "MV", "1x240", "ACC Building"})
        MyDataTable.Rows.Add({"CABLE", "LV", "1x240", "Swithgear "})
        MyDataTable.Rows.Add({"Install", "Cable Tray", "20", "Swithgear"})
        MyDataTable.Rows.Add({"Install", "Cable Tray", "30", "ACC"})
        MyDataTable.Rows.Add({"Install", "Cable Tray", "60", "ACC"})
        MyDataTable.Rows.Add({"Install", "JB", "10x10", "Admin"})
        MyDataTable.Rows.Add({"Install", "JB", "20x10", "Admin"})
        MyDataTable.Rows.Add({"Test", "Detector", "Smoke", "Admin"})
        MyDataTable.Rows.Add({"Test", "Detector", "Beam", "ACC"})
        MyDataTable.Rows.Add({"Test", "Detector", "Heat", "ACC"})
        Dim dynamicColumn = MyDataTable.Columns.Cast(Of DataColumn)().Select(Function(col) col.ColumnName).ToArray()
        Dim arrTree = (From row In MyDataTable.AsEnumerable()
                       Select dynamicColumn.Select(Function(h) row.Item(h)).ToArray).ToArray
        For Each item In arrTree
            Dim parentNode As TreeNode = Nothing
            For i = 0 To item.Length - 1
                Dim value1 = item(i).ToString()
                Dim node As TreeNode = Nothing
                If parentNode IsNot Nothing Then
                    node = parentNode.Nodes.Cast(Of TreeNode)() _
            .FirstOrDefault(Function(n) n.Text = value1)
                Else
                    node = TreeView1.Nodes.Cast(Of TreeNode)() _
            .FirstOrDefault(Function(n) n.Text = value1)
                End If
                If node IsNot Nothing Then
                    node.ForeColor = Color.FromArgb(0, 0, 0, 0)
                End If
                If node Is Nothing Then
                    node = New TreeNode(value1)
                    If parentNode IsNot Nothing Then
                        parentNode.Nodes.Add(node)
                    Else
                        TreeView1.Nodes.Add(node)
                    End If
                End If
                parentNode = node
            Next
        Next
    End Sub
    Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
        'Need Function To Find  
    End Sub

Answer 1

Hi @Mansour_Dalir ,

You can refer to the following code.

Imports System.Runtime.CompilerServices


Public Class Form1
    Dim MyDataTable As New DataTable
    Public dynamicColumn As String()
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        MyDataTable.Columns.Add("Group")
        MyDataTable.Columns.Add("Type")
        MyDataTable.Columns.Add("Size")
        MyDataTable.Columns.Add("Location")
        MyDataTable.Rows.Add({"CABLE", "MV", "1x240", "Air Building"})
        MyDataTable.Rows.Add({"CABLE", "MV", "1x240", "ACC Building"})
        MyDataTable.Rows.Add({"CABLE", "LV", "1x240", "Swithgear "})
        MyDataTable.Rows.Add({"Install", "Cable Tray", "20", "Swithgear"})
        MyDataTable.Rows.Add({"Install", "Cable Tray", "30", "ACC"})
        MyDataTable.Rows.Add({"Install", "Cable Tray", "60", "ACC"})
        MyDataTable.Rows.Add({"Install", "JB", "10x10", "Admin"})
        MyDataTable.Rows.Add({"Install", "JB", "20x10", "Admin"})
        MyDataTable.Rows.Add({"Test", "Detector", "Smoke", "Admin"})
        MyDataTable.Rows.Add({"Test", "Detector", "Beam", "ACC"})
        MyDataTable.Rows.Add({"Test", "Detector", "Heat", "ACC"})
        Dim dynamicColumn = MyDataTable.Columns.Cast(Of DataColumn)().Select(Function(col) col.ColumnName).ToArray()
        Dim arrTree = (From row In MyDataTable.AsEnumerable()
                       Select dynamicColumn.Select(Function(h) row.Item(h)).ToArray).ToArray
        For Each item In arrTree
            Dim parentNode As TreeNode = Nothing
            For i = 0 To item.Length - 1
                Dim value1 = item(i).ToString()
                Dim node As TreeNode = Nothing
                If parentNode IsNot Nothing Then
                    node = parentNode.Nodes.Cast(Of TreeNode)() _
            .FirstOrDefault(Function(n) n.Text = value1)
                Else
                    node = TreeView1.Nodes.Cast(Of TreeNode)() _
            .FirstOrDefault(Function(n) n.Text = value1)
                End If
                If node IsNot Nothing Then
                    node.ForeColor = Color.FromArgb(0, 0, 0, 0)

                End If
                If node Is Nothing Then
                    node = New TreeNode(value1)
                    If parentNode IsNot Nothing Then
                        parentNode.Nodes.Add(node)
                    Else
                        TreeView1.Nodes.Add(node)
                    End If
                End If
                parentNode = node
            Next
        Next
    End Sub
    Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
        Dim allNodes = TreeView1.Nodes.Find("", True).AsEnumerable()
        allNodes.ToList().ForEach(Sub(node) node.BackColor = Color.White)
        Dim nodes = TreeView1.FlattenTree().Where(Function(n) n.Text = TextBox1.Text).ToList()
        For Each tn As TreeNode In nodes
            tn.BackColor = Color.Red
        Next
    End Sub

End Class


Module SOExtension
    <Extension()>
    Function FlattenTree(ByVal tv As TreeView) As IEnumerable(Of TreeNode)
        Return FlattenTree(tv.Nodes)
    End Function

    <Extension()>
    Function FlattenTree(ByVal coll As TreeNodeCollection) As IEnumerable(Of TreeNode)
        Return coll.Cast(Of TreeNode)().Concat(coll.Cast(Of TreeNode)().SelectMany(Function(x) FlattenTree(x.Nodes)))
    End Function
End Module

Best Regards.

Jiachen Li

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