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TreeViewAction Enumeration

Specifies the action that raised a TreeViewEventArgs event.

[Visual Basic]
<Serializable>
Public Enum TreeViewAction
[C#]
[Serializable]
public enum TreeViewAction
[C++]
[Serializable]
__value public enum TreeViewAction
[JScript]
public
   Serializable
enum TreeViewAction

Remarks

This enumeration is used by members such as the TreeViewEventArgs constructor.

Members

Member name Description
ByKeyboard

Supported by the .NET Compact Framework.

The event was caused by a keystroke.
ByMouse

Supported by the .NET Compact Framework.

The event was caused by a mouse operation.
Collapse

Supported by the .NET Compact Framework.

The event was caused by the TreeNode collapsing.
Expand

Supported by the .NET Compact Framework.

The event was caused by the TreeNode expanding.
Unknown

Supported by the .NET Compact Framework.

The action that caused the event is unknown.

Example

[Visual Basic, C#] The following code example demonstrates how to use the AfterSelect event and the TreeViewAction enumeration. To run the example paste the following code in a form containing a TreeView control named TreeView1.

[Visual Basic] 
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 LabelEdit property to false so the user cannot
    ' edit this label.  
    If (e.Node Is TreeView1.TopNode) Then

        TreeView1.LabelEdit = False
        MessageBox.Show("You are not allowed to edit the top node")
    End If

    ' Set the LabelEdit property to true again.
    TreeView1.LabelEdit = True
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

[C#] 
private void InitializeTreeView()
{

    // Construct the TreeView object.
    this.TreeView1 = new System.Windows.Forms.TreeView();

    // Set dock, location, size name, and tab order
    // values for the TreeView object.
    TreeView1.Dock = System.Windows.Forms.DockStyle.Left;
    TreeView1.Location = new System.Drawing.Point(0, 0);
    TreeView1.Name = "TreeView1";
    TreeView1.Size = new System.Drawing.Size(152, 266);
    TreeView1.TabIndex = 1;
    
    // Associate the event-handling methods with the
    // BeforeLabeEdit and the AfterSelect events.
    TreeView1.BeforeLabelEdit += 
        new NodeLabelEditEventHandler(TreeView1_BeforeLabelEdit);
    TreeView1.AfterSelect += 
        new TreeViewEventHandler(TreeView1_AfterSelect);

    // Set the LabelEdit property to true to allow the 
    // user to edit the TreeNode text.
    this.TreeView1.LabelEdit = true;

    // Declare and create objects needed to populate 
    // the TreeView.
    string[] files = new string[]{"bigPresentation.ppt", 
        "myFinances.xls", "myResume.doc"};; 
    string filePath = "c:\\myFiles";
    System.Collections.ArrayList nodes = 
        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.
    foreach ( string file in files )
    {
        TreeNode node = new TreeNode(file);
        node.Tag = filePath+"\\"+file;
        nodes.Add(node);
    }

    TreeNode[] treeNodes = new TreeNode[nodes.Count];
    nodes.CopyTo(treeNodes);

    // Create a new node named topNode and add the ArrayList of 
    // nodes to topNode.
    TreeNode topNode = new TreeNode("myFiles",  treeNodes);
    topNode.Tag = filePath;

    // Add topNode to the TreeView.
    TreeView1.Nodes.Add(topNode);

    // Add the TreeView to the form.
    this.Controls.Add(TreeView1);
}

private void TreeView1_BeforeLabelEdit(object sender, 
    NodeLabelEditEventArgs e)
{

    // Determine whether the user has selected the top node. If so,
    // change the LabelEdit property to false so the user cannot
    // edit this label.  
    if (e.Node == TreeView1.TopNode)

    {
        TreeView1.LabelEdit = false;
        MessageBox.Show("You are not allowed to edit the top node");
    }
    // Set the LabelEdit property to true again.
    TreeView1.LabelEdit = true;
}
. . . 
// Handle the After_Select event.
private void TreeView1_AfterSelect(System.Object sender, 
    System.Windows.Forms.TreeViewEventArgs e)
{

    // Vary the response depending on which TreeViewAction
    // triggered the event. 
    switch((e.Action))
    {
        case TreeViewAction.ByKeyboard:
            MessageBox.Show("You like the keyboard!");
            break;
        case TreeViewAction.ByMouse:
            MessageBox.Show("You like the mouse!");
            break;
    }
}

[C++, JScript] No example is available for C++ or JScript. To view a Visual Basic or C# example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Namespace: System.Windows.Forms

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

Assembly: System.Windows.Forms (in System.Windows.Forms.dll)

See Also

System.Windows.Forms Namespace | TreeViewEventArgs

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