TreeView.BeforeLabelEdit Event
.NET Framework (current version)
Occurs before the tree node label text is edited.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
For more information about how to handle events, see Handling and Raising Events.
The following code example demonstrates how to use the BeforeLabelEditAfterSelect and TopNode members. To run this example, paste the following code in a form that contains a TreeView control that is named TreeView1. Call the InitializeTreeView method in the form's constructor or Load method.
Private Sub InitializeTreeView() ' Construct the TreeView object. Me.TreeView1 = New System.Windows.Forms.TreeView ' Set dock, location, size name, and tab order ' values for the TreeView object. With TreeView1 .Dock = System.Windows.Forms.DockStyle.Left .Location = New System.Drawing.Point(0, 0) .Name = "TreeView1" .Size = New System.Drawing.Size(152, 266) .TabIndex = 1 End With ' Set the LabelEdit property to true to allow the ' user to edit the TreeNode text. Me.TreeView1.LabelEdit = True ' Declare and create objects needed to populate ' the TreeView. Dim file, files(), filePath As String files = New String() {"bigPresentation.ppt", "myFinances.xls", _ "myResume.doc"} filePath = "c:\myFiles" Dim nodes As New System.Collections.ArrayList ' Create a node for each file, setting the Text property to the ' file's name and the Tag property to file's fully-qualified name. For Each file In files Dim node As New TreeNode(file) node.Tag = filePath & "\" & file nodes.Add(node) Next ' Create a new node named topNode and add the ArrayList of ' nodes to topNode. Dim topNode As New TreeNode("myFiles", _ nodes.ToArray(GetType(TreeNode))) topNode.Tag = filePath ' Add topNode to the TreeView. TreeView1.Nodes.Add(topNode) ' Add the TreeView to the form. Me.Controls.Add(TreeView1) End Sub Private Sub TreeView1_BeforeLabelEdit(ByVal sender As Object, _ ByVal e As NodeLabelEditEventArgs) Handles TreeView1.BeforeLabelEdit ' Determine whether the user has selected the top node. If so, ' change the CancelEdit property to true to cancel the edit. If (e.Node Is TreeView1.TopNode) Then e.CancelEdit = True MessageBox.Show("You are not allowed to edit the top node") End If End Sub
' Handle the After_Select event. Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, _ ByVal e As System.Windows.Forms.TreeViewEventArgs) _ Handles TreeView1.AfterSelect ' Vary the response depending on which TreeViewAction ' triggered the event. Select Case (e.Action) Case TreeViewAction.ByKeyboard MessageBox.Show("You like the keyboard!") Case TreeViewAction.ByMouse MessageBox.Show("You like the mouse!") End Select End Sub
.NET Framework
Available since 1.1
Available since 1.1
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