【原】Save TreeView Nodes Expansion/Collapse & Checkboxes State In Session

VB CODE:

 

Imports Microsoft.VisualBasic
Imports System.Collections.Generic
 
Public Class TreeViewState
    Private RestoreTreeViewIndex As Integer
    Public Sub SaveTreeView(ByVal treeView As TreeView, ByVal key As String)
        Dim listExpanded As New List(Of Nullable(Of Boolean))
        Dim listChecked As New List(Of Nullable(Of Boolean))
        SaveTreeViewExpandedState(treeView.Nodes, listExpanded)
        SaveTreeViewCheckedState(treeView.Nodes, listChecked)
        HttpContext.Current.Session("1" + key + treeView.ID) = listExpanded
        HttpContext.Current.Session("2" + key + treeView.ID) = listChecked
    End Sub
 
    Private Sub SaveTreeViewExpandedState(ByVal nodes As TreeNodeCollection, ByVal list As List(Of Nullable(Of Boolean)))
        For Each node As TreeNode In nodes
            list.Add(node.Expanded)
            If node.ChildNodes.Count > 0 Then
                SaveTreeViewExpandedState(node.ChildNodes, list)
            End If
        Next
    End Sub
    Private Sub SaveTreeViewCheckedState(ByVal nodes As TreeNodeCollection, ByVal list As List(Of Nullable(Of Boolean)))
        For Each node As TreeNode In nodes
            Dim showCheckbox As Nullable(Of Boolean) = node.ShowCheckBox
            Dim isChecked As Boolean = False
            If showCheckbox.HasValue Then
                isChecked = CType(node.ShowCheckBox, Boolean) And node.Checked
                'If isChecked Then
                '    System.Diagnostics.Debug.Write("X")
                'End If
            End If
            list.Add(isChecked)
            If node.ChildNodes.Count > 0 Then
                SaveTreeViewCheckedState(node.ChildNodes, list)
            End If
        Next
    End Sub
 
 
    Public Sub RestoreTreeView(ByVal treeView As TreeView, ByVal key As String)
        Dim listExpanded As New List(Of Nullable(Of Boolean))
        Dim listChecked As New List(Of Nullable(Of Boolean))
        If HttpContext.Current.Session("1" + key + treeView.ID) IsNot Nothing Then
            listExpanded = CType(HttpContext.Current.Session("1" + key + treeView.ID), List(Of Nullable(Of Boolean)))
            listChecked = CType(HttpContext.Current.Session("2" + key + treeView.ID), List(Of Nullable(Of Boolean)))
       End If
 
        RestoreTreeViewIndex = 0
        RestoreTreeViewExpandedState(treeView.Nodes, listExpanded)
        RestoreTreeViewIndex = 0
        RestoreTreeViewCheckedState(treeView.Nodes, listChecked)
    End Sub
 
    Private Sub RestoreTreeViewExpandedState(ByVal nodes As TreeNodeCollection, ByVal list As List(Of Nullable(Of Boolean)))
        For Each node As TreeNode In nodes
            If RestoreTreeViewIndex >= list.Count Then Exit Sub
 
            node.Expanded = list(RestoreTreeViewIndex)
            RestoreTreeViewIndex += 1
 
            If node.ChildNodes.Count > 0 Then
                RestoreTreeViewExpandedState(node.ChildNodes, list)
            End If
        Next
    End Sub
    Private Sub RestoreTreeViewCheckedState(ByVal nodes As TreeNodeCollection, ByVal list As List(Of Nullable(Of Boolean)))
        For Each node As TreeNode In nodes
            If RestoreTreeViewIndex >= list.Count Then Exit Sub
 
            node.Checked = list(RestoreTreeViewIndex)
            'If node.Checked Then
            '    System.Diagnostics.Debug.Write("X")
            'End If
            RestoreTreeViewIndex += 1
 
            If node.ChildNodes.Count > 0 Then
                RestoreTreeViewCheckedState(node.ChildNodes, list)
            End If
        Next
    End Sub
End Class

 

C# CODE:

 

using System.Collections.Generic; 

public class TreeViewState 
{ 
    private int RestoreTreeViewIndex; 
    public void SaveTreeView(TreeView treeView, string key) 
    { 
        List<Nullable<bool>> listExpanded = new List<Nullable<bool>>(); 
        List<Nullable<bool>> listChecked = new List<Nullable<bool>>(); 
        SaveTreeViewExpandedState(treeView.Nodes, listExpanded); 
        SaveTreeViewCheckedState(treeView.Nodes, listChecked); 
        HttpContext.Current.Session("1" + key + treeView.ID) = listExpanded; 
        HttpContext.Current.Session("2" + key + treeView.ID) = listChecked; 
    } 
    
    private void SaveTreeViewExpandedState(TreeNodeCollection nodes, List<Nullable<bool>> list) 
    { 
        foreach (TreeNode node in nodes) { 
            list.Add(node.Expanded); 
            if (node.ChildNodes.Count > 0) { 
                SaveTreeViewExpandedState(node.ChildNodes, list); 
            } 
        } 
    } 
    private void SaveTreeViewCheckedState(TreeNodeCollection nodes, List<Nullable<bool>> list) 
    { 
        foreach (TreeNode node in nodes) { 
            Nullable<bool> showCheckbox = node.ShowCheckBox; 
            bool isChecked = false; 
            if (showCheckbox.HasValue) { 
                isChecked = (bool)node.ShowCheckBox & node.Checked; 
            } 
            //If isChecked Then 
            // System.Diagnostics.Debug.Write("X") 
            //End If 
            list.Add(isChecked); 
            if (node.ChildNodes.Count > 0) { 
                SaveTreeViewCheckedState(node.ChildNodes, list); 
            } 
        } 
    } 
    
    
    public void RestoreTreeView(TreeView treeView, string key) 
    { 
        List<Nullable<bool>> listExpanded = new List<Nullable<bool>>(); 
        List<Nullable<bool>> listChecked = new List<Nullable<bool>>(); 
        if (HttpContext.Current.Session("1" + key + treeView.ID) != null) { 
            listExpanded = (List<Nullable<bool>>)HttpContext.Current.Session("1" + key + treeView.ID); 
            listChecked = (List<Nullable<bool>>)HttpContext.Current.Session("2" + key + treeView.ID); 
        } 
        
        RestoreTreeViewIndex = 0; 
        RestoreTreeViewExpandedState(treeView.Nodes, listExpanded); 
        RestoreTreeViewIndex = 0; 
        RestoreTreeViewCheckedState(treeView.Nodes, listChecked); 
    } 
    
    private void RestoreTreeViewExpandedState(TreeNodeCollection nodes, List<Nullable<bool>> list) 
    { 
        foreach (TreeNode node in nodes) { 
            if (RestoreTreeViewIndex >= list.Count) return; 

            
            node.Expanded = list(RestoreTreeViewIndex); 
            RestoreTreeViewIndex += 1; 
            
            if (node.ChildNodes.Count > 0) { 
                RestoreTreeViewExpandedState(node.ChildNodes, list); 
            } 
        } 
    } 
    private void RestoreTreeViewCheckedState(TreeNodeCollection nodes, List<Nullable<bool>> list) 
    { 
        foreach (TreeNode node in nodes) { 
            if (RestoreTreeViewIndex >= list.Count) return; 

            
            node.Checked = list(RestoreTreeViewIndex); 
            //If node.Checked Then 
            // System.Diagnostics.Debug.Write("X") 
            //End If 
            RestoreTreeViewIndex += 1; 
            
            if (node.ChildNodes.Count > 0) { 
                RestoreTreeViewCheckedState(node.ChildNodes, list); 
            } 
        } 
    } 
} 

 

Reference Information:

http://blog.binaryocean.com/2006/01/19/SaveTreeViewNodesExpansionCollapseStateCSAndVB.aspx