A tree control responds to the arrow keys, PgUp, PgDn, Up, Down, Home, End, etc. to change the selected item.

Typing one or more alphanumeric characters while a tree control has the input focus will reposition the selection on a matching item, based on the CharSearchMode and CharSearchDisplayColumn properties.

Left Arrow - If the current item is an expanded parent item, the left arrow key will collapse the item. Otherwise, the left arrow key will change the current item to the item's immediate parent item.

Right Arrow - If the current item is a collapsed parent item, the right arrow key will expand the item. Otherwise, the right arrow key will change the current item to the first immediate dependent item.

+ (numeric keypad) - If the current item is a collapsed parent item, the + key will generate an ItemClick (ItemClickAreaEnum.ExpandCollapseButton) event to expand the item. Otherwise, the + key will have no effect. If AutoRespond is set to True, the ItemClick event is automatically handled, resulting in the item being expanded. If AutoRespond is set to False, the ItemClick event must be handled by the application. 

- (numeric keypad) - If the current item is an expanded parent item, the - key will generate an ItemClick (ItemClickAreaEnum.ExpandCollapseButton) event to collapse the item. Otherwise, the - key will have no effect. If AutoRespond is set to True, the ItemClick event is automatically handled, resulting in the item being collapsed. If AutoRespond is set to False, the ItemClick event must be handled by the application.

* (numeric keypad) - If the current item is a collapsed parent item, the * key will generate an ItemClick (ItemClickAreaEnum.ExpandCollapseButtonAll) event to expand the item completely. Otherwise, the * key will have no effect. If AutoRespond is set to True, the ItemClick event is automatically handled, resulting in the item being expanded. If AutoRespond is set to False, the ItemClick event must be handled by the application. 

Return - The HandleReturn property can be used to determine handling and support of the Return key.

Space Bar - The space bar selects/deselects the current item (honoring the Control and Shift keys).