By default, the AllowSelectNothing property is True, which indicates that all elements are unselected when user clicks an empty part of the surface. The AllowSelectNothing property indicates whether the selection is cleared once the user clicks any empty area on the surface. Set the AllowSelectNothing property on False to prevent un-selecting elements when clicking any empty part of rge surface. The AllowSelectObject property indicates the keys combination to allow user selecting new elements. The SelectionChanged event occurs once a new element is selected or unselected. The Selectable property of the Element object indicates whether the element is selectable or un-selectable. The AllowSelectObjectRect property specifies the keys combination so the user can select the elements from the dragging rectangle. The SelectAll method selects all elements in the chart. Use the UnselectAll method to unselect all elements on the surface. The SingleSel property specifies whether the surface allows selecting one or multiple elements. The SelCount property counts the number of selected elements. The SelElement property returns the selected element based on its index in the selected elements collection. The Selection property sets or gets a safe array of selected elements. The control fires the LayoutStartChanging(exSelectNothing) / LayoutEndChanging(exSelectNothing) event when the user selects nothing ( click an empty area on the surface).