TVS_CHECKBOXES
Version 4.70. Enables check boxes for items in a tree-view control. A check box is displayed only if an image is associated with the item. When set to this style, the control effectively uses DrawFrameControl to create and set a state image list containing two images. State image 1 is the unchecked box and state image 2 is the checked box. Setting the state image to zero removes the check box altogether.