TdxTreeViewNodeAllowEvent Type
In This Article
The action permission procedural type for tree nodes.
#Declaration
Delphi
TdxTreeViewNodeAllowEvent = procedure(Sender: TdxCustomTreeView; ANode: TdxTreeViewNode; var Allow: Boolean) of object;
#Parameters
Name | Type | Description |
---|---|---|
Sender | Tdx |
The Tree View control that raised an action permission event. |
ANode | Tdx |
The target tree node. |
Allow | Boolean | Assign False to this parameter to prohibit users from performing the action. To allow the action, assign False to the parameter. |
#Remarks
The OnCollapsing event handler below prohibits the control from collapsing nodes at the top nesting level:
procedure TForm1.dxTreeViewControl1Collapsing(Sender: TdxCustomTreeView;
ANode: TdxTreeViewNode; var Allow: Boolean);
begin
if ANode.Parent = Sender.Root then
Allow := False;
end;
The following Tree View events reference the TdxTreeViewNodeAllowEvent type:
See Also