I'm all new to this treeview business. I have a fixed treeview, very simple and basic. Only two levels, parent and child nodes. I just need two things out of this treeview.
1) If parent is checked, check all child nodes.
2) If just one child node is unchecked, uncheck parent node.
That's it! I've been looking for this for 30 mins and I cant find it. Maybe because my vb.net is old, it doesnt seem to be the same as others =/ I'm using vb.net 2003. Thank you very much :D
Working example in VB.Net 2008, but it should work in 2003:
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
For i As Integer = 1 To 3
Dim node As New TreeNode("Parent #" & i.ToString)
node.Nodes.Add("Child #1")
node.Nodes.Add("Child #2")
node.Expand()
TreeView1.Nodes.Add(node)
Next
End Sub
Private Sub TreeView1_AfterCheck(ByVal sender As Object, ByVal e As TreeViewEventArgs) Handles TreeView1.AfterCheck
RemoveHandler TreeView1.AfterCheck, AddressOf TreeView1_AfterCheck
For Each node As TreeNode In e.Node.Nodes
node.Checked = e.Node.Checked
Next
If e.Node.Checked Then
If e.Node.Parent Is Nothing = False Then
Dim allChecked As Boolean = True
For Each node As TreeNode In e.Node.Parent.Nodes
If Not node.Checked Then
allChecked = False
End If
Next
If allChecked Then
e.Node.Parent.Checked = True
End If
End If
Else
If e.Node.Parent Is Nothing = False Then
e.Node.Parent.Checked = False
End If
End If
AddHandler TreeView1.AfterCheck, AddressOf TreeView1_AfterCheck
End Sub
You may want to try this shorter version
Private Sub treeview1_AfterCheck(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles treeview1.AfterCheck
Dim objNode As TreeNode = e.Node
Dim bCheck As Boolean = e.Node.Checked
For Each ChildNode As TreeNode In objNode.Nodes
ChildNode.Checked = bCheck
Next
End Sub
I had basically the same requirement, but I also wanted that if all child nodes are checked, check the parent node.
Here is my code tested today in VS 2013:
Private Sub TreeView1_AfterCheck(sender As Object, e As TreeViewEventArgs) Handles TreeView1.AfterCheck
If e.Action <> TreeViewAction.ByMouse And e.Action <> TreeViewAction.ByKeyboard Then Exit Sub
Dim CheckedNode As TreeNode = e.Node
Dim CheckedNodeIsRoot As Boolean = CheckedNode.Parent Is Nothing
Dim ParentNode As TreeNode = CheckedNode.Parent
Dim ChildOneUnchecked As Boolean = False
If CheckedNodeIsRoot Then
For Each ChildNode As TreeNode In CheckedNode.Nodes
ChildNode.Checked = CheckedNode.Checked
Next
Else
If CheckedNode.Checked Then
For Each ChildNode As TreeNode In ParentNode.Nodes
If Not ChildNode.Checked Then ChildOneUnchecked = True
Next
If ChildOneUnchecked Then
ParentNode.Checked = False
Else
ParentNode.Checked = True
End If
Else
ParentNode.Checked = False
End If
End If
End Sub
This works on VB.net 2010. it is based on Daniel Lee code
Private Sub TreeView1_AfterCheck(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterCheck
Dim childNodeCK As TreeNode = e.Node
Dim NodeChecked As Boolean = e.Node.Checked
For Each ChildNode As TreeNode In childNodeCK.Nodes
If NodeChecked = True Then
ChildNode.Checked = NodeChecked
End If
Next
If childNodeCK.Checked = False Then
If e.Node.Parent Is Nothing = False Then
e.Node.Parent.Checked = False
End If
End If
End Sub
Private Sub Tv1_AfterCheck(sender As Object, e As TreeViewEventArgs) Handles Tv1.AfterCheck
Try
Dim A As Boolean = e.Node.Checked
If e.Action = TreeViewAction.ByMouse Or e.Action = TreeViewAction.ByKeyboard Then
CUchkall(e.Node, A)
End If
UnCheckParentNodes(e.Node)
Call CuChild(e.Node)
Catch
End Try
End Sub
Private Sub CuChild(ByVal iNode As TreeNode)
Try
Dim E As Boolean = True
If iNode.Parent IsNot Nothing Then
For Each M As TreeNode In iNode.Parent.Nodes
If M.Checked = False Then E = False
Next
iNode.Parent.Checked = E
End If
Catch
End Try
End Sub
Private Sub CUchkall(ByVal iNode As TreeNode, COU As Boolean)
Try
If iNode.Nodes IsNot Nothing Then
For Each N As TreeNode In iNode.Nodes
N.Checked = COU
Call CUchkall(N, COU)
Next
End If
Catch
End Try
End Sub
Private Sub UnCheckParentNodes(ByVal iNode As TreeNode)
Try
If iNode.Checked = False AndAlso iNode.Parent IsNot Nothing Then
iNode.Parent.Checked = False
UnCheckParentNodes(iNode.Parent)
End If
Catch
End Try
End Sub
I modify Javier Arce codes for multilevel treeview (recursive version). Here is my codes.
Private Sub treeTestsSelection_AfterCheck(sender As Object, e As TreeViewEventArgs) Handles treeTestsSelection.AfterCheck
If e.Action <> TreeViewAction.ByMouse And e.Action <> TreeViewAction.ByKeyboard Then Exit Sub
CheckAllNodes(e.Node)
CheckAllNodesForParent(e.Node)
End Sub
Public Sub CheckAllNodes(ByRef TreeNodeToCheck As TreeNode)
Dim val As Boolean = TreeNodeToCheck.Checked
For Each n As TreeNode In TreeNodeToCheck.Nodes
n.Checked = val
If n.GetNodeCount(True) > 0 Then
CheckAllNodes(n)
End If
Next
End Sub
Public Sub CheckAllNodesForParent(ByRef CheckedTreeNode As TreeNode)
If CheckedTreeNode.Checked Then
If CheckedTreeNode.Parent Is Nothing = False Then
Dim allChecked As Boolean = True
For Each node As TreeNode In CheckedTreeNode.Parent.Nodes
If Not node.Checked Then
allChecked = False
End If
Next
If allChecked Then
CheckedTreeNode.Parent.Checked = True
CheckAllNodesForParent(CheckedTreeNode.Parent)
End If
End If
Else
If CheckedTreeNode.Parent Is Nothing = False Then
CheckedTreeNode.Parent.Checked = False
CheckAllNodesForParent(CheckedTreeNode.Parent)
End If
End If
End Sub
