Option Strict On
''' <summary>
''' The TreeViewDataAccess class allows the nodes within a TreeView to be
''' persisted to xml for later retrevial.
''' </summary>
Public Class TreeViewDataAccess
'=============================
'----- START EDITED ----------
'=============================
Public Shared n As Integer
Public Shared tn As TreeNode
'=============================
'----- END EDITED ------------
'=============================
#Region "Structures"
''' <summary>
''' TreeViewData structure represents the root node collection of a TreeView
''' and provides the PopulateTreeView function to add these nodes to a specified
''' TreeView instance.
''' </summary>
<Serializable()> Public Structure TreeViewData
''' <summary>Array of TreeNodeData objects representing the root nodes in a TreeView.</summary>
Public Nodes() As TreeNodeData
''' <summary>
''' Creates new instance of the TreeViewData structure based from the
''' specified TreeView.
''' </summary>
''' <param name="treeview">TreeView to build the TreeViewData instance from.</param>
Public Sub New(ByVal treeview As TreeView)
'Check to see if there are any root nodes in the TreeView
If treeview.Nodes.Count = 0 Then Exit Sub
'Populate the Nodes array with child nodes
ReDim Nodes(treeview.Nodes.Count - 1)
For i As Integer = 0 To treeview.Nodes.Count - 1
Nodes(i) = New TreeNodeData(treeview.Nodes(i))
Next
End Sub
''' <summary>
''' Populates the specified TreeView with the current TreeViewData instance.
''' </summary>
''' <param name="treeview">TreeView instance to populate.</param>
Public Sub PopulateTree(ByVal treeview As TreeView)
'Check to see if there are any root nodes in the TreeViewData
If Me.Nodes Is Nothing OrElse Me.Nodes.Length = 0 Then Exit Sub
'Populate the TreeView with child nodes
treeview.BeginUpdate()
For i As Integer = 0 To Me.Nodes.Length - 1
treeview.Nodes.Add(Me.Nodes(i).ToTreeNode())
'=============================
'----- START EDITED ----------
'=============================
If Me.Nodes(i).Selected Then
tn = Me.Nodes(i).ToTreeNode
n = i
End If
'=============================
'----- END EDITED ------------
'=============================
Next
treeview.EndUpdate()
'=============================
'----- START EDITED ----------
'=============================
If tn.Level > 0 Then
treeview.SelectedNode = tn
ElseIf n > -1 Then
treeview.SelectedNode = treeview.Nodes(n)
End If
'=============================
'----- END EDITED ------------
'=============================
End Sub
End Structure
''' <summary>
''' TreeNodeData structure represents a TreeNode and provides the
''' ToTreeNode function to convert the instance to a TreeNode object.
''' </summary>
<Serializable()> Public Structure TreeNodeData
''' <summary>String representing the Text property of the TreeNode.</summary>
Public Text As String
''' <summary>Integer representing the ImageIndex property of the TreeNode.</summary>
Public ImageIndex As Integer
''' <summary>Integer representing the SelectedImageIndex property of the TreeNode.</summary>
Public SelectedImageIndex As Integer
''' <summary>Boolean representing the Checked state of the TreeNode.</summary>
Public Checked As Boolean
''' <summary>Boolean representing the Expanded state of the TreeNode.</summary>
Public Expanded As Boolean
''' <summary>Object representing the Tag property of the TreeNode.</summary>
Public Tag As Object
'=============================
'----- START EDITED ----------
'=============================
''' <summary>Boolean representing the Selected property of the TreeNode.</summary>
Public Selected As Boolean
'=============================
'----- END EDITED ------------
'=============================
''' <summary>Array of TreeNodeData objects representing the root nodes in a TreeView.</summary>
Public Nodes() As TreeNodeData
''' <summary>
''' Creates new instance of the TreeNodeData structure based on the specified TreeNode.
''' </summary>
''' <param name="node">TreeNode to build the TreeNodeData instance from.</param>
Public Sub New(ByVal node As TreeNode)
'Set the basic TreeNode properties
Me.Text = node.Text
Me.ImageIndex = node.ImageIndex
Me.SelectedImageIndex = node.SelectedImageIndex
Me.Checked = node.Checked
Me.Expanded = node.IsExpanded
'=============================
'----- START EDITED ----------
'=============================
Me.Selected = node.IsSelected
'=============================
'----- END EDITED ------------
'=============================
'See if there is an object in the tag property and if it is serializable
If (Not node.Tag Is Nothing) AndAlso node.Tag.GetType.IsSerializable Then Me.Tag = node.Tag
'Check to see if there are any child nodes
If node.Nodes.Count = 0 Then Exit Sub
'Recurse through child nodes and add to Nodes array
ReDim Nodes(node.Nodes.Count - 1)
For i As Integer = 0 To node.Nodes.Count - 1
Nodes(i) = New TreeNodeData(node.Nodes(i))
Next
End Sub
''' <summary>
''' Returns as TreeNode built from the instance of the TreeNodeData object.
''' </summary>
Public Function ToTreeNode() As TreeNode
'Create TreeNode based on instance of TreeNodeData and set basic properties
ToTreeNode = New TreeNode(Me.Text, Me.ImageIndex, Me.SelectedImageIndex)
ToTreeNode.Checked = Me.Checked
ToTreeNode.Tag = Me.Tag
If Me.Expanded Then ToTreeNode.Expand()
'=============================
'----- START EDITED ----------
'=============================
If Me.Selected Then tn = ToTreeNode
'=============================
'----- END EDITED ------------
'=============================
'Recurse through child nodes adding to Nodes collection
If Me.Nodes Is Nothing OrElse Me.Nodes.Length = 0 Then Exit Function
For i As Integer = 0 To Me.Nodes.Length - 1
ToTreeNode.Nodes.Add(Me.Nodes(i).ToTreeNode())
Next
End Function
End Structure
#End Region
#Region "Public"
''' <summary>
''' Populates the specified TreeView from the serialized TreeViewData structure file specified.
''' </summary>
''' <param name="treeView">TreeView instance to populate.</param>
''' <param name="path">Serialized Xml representation of TreeViewData</param>
Public Shared Sub LoadTreeViewData(ByVal treeView As TreeView, ByVal path As String)
'Create as serializer and get the file to deserialize
Dim ser As New System.Xml.Serialization.XmlSerializer(GetType(TreeViewData))
Dim file As New System.IO.FileStream(path, IO.FileMode.Open)
Dim reader As New System.Xml.XmlTextReader(file)
'Deserialize the file and populate the treeview
Dim treeData As TreeViewData = CType(ser.Deserialize(reader), TreeViewData)
treeData.PopulateTree(treeView)
'Tidy up
reader.Close()
file.Close()
file = Nothing
End Sub
''' <summary>
''' Saves the specified TreeView in serialized TreeViewData structure file specified.
''' </summary>
''' <param name="treeView">TreeView instance to save.</param>
''' <param name="path">Path to store serialized file.</param>
Public Shared Sub SaveTreeViewData(ByVal treeView As TreeView, ByVal path As String)
'Create as serializer and file to save TreeViewData
Dim ser As New System.Xml.Serialization.XmlSerializer(GetType(TreeViewData))
Dim file As New System.IO.FileStream(path, IO.FileMode.Create)
Dim writer As New System.Xml.XmlTextWriter(file, Nothing)
'Generate TreeViewData from TreeView and serialize the file.
ser.Serialize(writer, New TreeViewData(treeView))
'Tidy up
writer.Close()
file.Close()
file = Nothing
End Sub
#End Region
End Class
[RESOLVED] [2008] Copying state of Treeview
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Originally Posted by NickThissen
