TreeListOptionsMenu.ShowExpandCollapseItems Property

Gets or sets whether to show the expand/collapse commands in the context menu invoked with a right-click on a node.

Namespace: DevExpress.XtraTreeList

Assembly: DevExpress.XtraTreeList.v23.2.dll

NuGet Packages: DevExpress.Win.Navigation, DevExpress.Win.TreeList

Declaration

C#

[DefaultValue(true)]
[XtraSerializableProperty]
public virtual bool ShowExpandCollapseItems { get; set; }

VB.NET

<DefaultValue(True)>
<XtraSerializableProperty>
Public Overridable Property ShowExpandCollapseItems As Boolean

Property Value

Type	Default	Description
Boolean	true	true, to show the expand/collapse commands in the context menu invoked with a right-click on a node; otherwise, false.

Property Paths

You can access this nested property as listed below:

Object Type	Path to ShowExpandCollapseItems
TreeList	.OptionsMenu .ShowExpandCollapseItems

Remarks

If the TreeList.OptionsMenu.EnableNodeMenu option is enabled, the tree list shows a context menu when a user right-clicks a node.

Predefined Commands

The context menu contains the following predefined commands:

• Collapse (Expand) — collapses (expands) the clicked node. This command is only shown when the node has children.
• Full Collapse — collapses all nodes.
• Full Expand — expands all nodes.

To hide these commands, use the TreeList.OptionsMenu.ShowExpandCollapseItems option.

If the control displays the New Item Row, the context menu also contains the following commands:

• Add Node — creates a new node at the same level as the focused node.
• Add Child Node — creates a new child node for the focused node.

To hide/show these commands regardless of whether the New Item Row is displayed, use the TreeList.OptionsMenu.ShowAddNodeItems option.

Localize the Menu

The TreeListLocalizer allows you to localize the command captions. Use the following fields to identify a command:

• MenuNodeCollapse — the Collapse command.
• MenuNodeExpand — the Expand command.
• MenuNodeExpandAll — the Full Expand command.
• MenuNodeCollapseAll — the Full Collapse command.
• MenuNodeAddNode — the Add Node command.
• MenuNodeAddChildNode — the Add Child Node command.

C#

using DevExpress.XtraTreeList.Localization;

TreeListLocalizer.Active = new NodeContextMenuLocalizer();

public class NodeContextMenuLocalizer : TreeListLocalizer {
    public override string Language { get { return "English"; } }
    public override string GetLocalizedString(TreeListStringId id) {
        switch (id) {
            case TreeListStringId.MenuNodeCollapse: return "Collapse this node";
            case TreeListStringId.MenuNodeExpand: return "Expand this node";
            case TreeListStringId.MenuNodeExpandAll: return "Expand all nodes";
            case TreeListStringId.MenuNodeCollapseAll: return "Collapse all nodes";
            default: return base.GetLocalizedString(id);
        }
    }
}

VB.NET

Imports DevExpress.XtraTreeList.Localization

TreeListLocalizer.Active = New NodeContextMenuLocalizer()

Public Class NodeContextMenuLocalizer
    Inherits TreeListLocalizer

    Public Overrides ReadOnly Property Language() As String
        Get
            Return "English"
        End Get
    End Property
    Public Overrides Function GetLocalizedString(ByVal id As TreeListStringId) As String
        Select Case id
            Case TreeListStringId.MenuNodeCollapse
                Return "Collapse this node"
            Case TreeListStringId.MenuNodeExpand
                Return "Expand this node"
            Case TreeListStringId.MenuNodeExpandAll
                Return "Expand all nodes"
            Case TreeListStringId.MenuNodeCollapseAll
                Return "Collapse all nodes"
            Case Else
                Return MyBase.GetLocalizedString(id)
        End Select
    End Function
End Class

Populate the Menu

You can handle the TreeList.PopupMenuShowing event to populate the menu with custom items.

C#

using DevExpress.XtraTreeList;
using DevExpress.XtraTreeList.Menu;

treeList1.PopupMenuShowing += OnPopupMenuShowing;

void OnPopupMenuShowing(object sender, PopupMenuShowingEventArgs e) {
    if (e.Menu is DevExpress.XtraTreeList.Menu.TreeListNodeMenu) {
        AddItem(e.Menu, NodeMenuItemID.Indent, treeList1.CanIndentNodes(treeList1.Selection));
        AddItem(e.Menu, NodeMenuItemID.Outdent, treeList1.CanOutdentNodes(treeList1.Selection));
        e.Allow = true;
    }
}

VB.NET

Imports DevExpress.XtraTreeList
Imports DevExpress.XtraTreeList.Menu

AddHandler treeList1.PopupMenuShowing, AddressOf OnPopupMenuShowing

Private Sub OnPopupMenuShowing(ByVal sender As Object, ByVal e As PopupMenuShowingEventArgs)
    If TypeOf e.Menu Is DevExpress.XtraTreeList.Menu.TreeListNodeMenu Then
        AddItem(e.Menu, NodeMenuItemID.Indent, treeList1.CanIndentNodes(treeList1.Selection))
        AddItem(e.Menu, NodeMenuItemID.Outdent, treeList1.CanOutdentNodes(treeList1.Selection))
        e.Allow = True
    End If
End Sub

Note

Run the XtraTreeList demo and click Open Solution to see the complete example.