void MyFrame::OnTreeItemExpanding(wxTreeEvent& event) { // Check if we should allow expanding the item if (/* some condition */) { // Allow expanding the item event.Skip(); } else { // Veto the event event.Veto(); } }
void MyFrame::OnTreeItemSelect(wxTreeEvent& event) { // Check if we should allow selecting the item if (/* some condition */) { // Allow selecting the item event.Skip(); } else { // Veto the event event.Veto(); } }In this example, we have an event handler for when a tree item is about to be selected. We again check if we want to allow the item to be selected. If we want to allow it, we call `event.Skip()` to let the event continue as usual. If we want to prevent the item from being selected, we call `event.Veto()` to veto the event. These examples demonstrate how wxTreeEvent Veto can be used to control certain events in a tree control. The wxWidgets library is used to implement this feature.