[Overview][Types][Classes][Procedures and functions][Index] | Reference for unit 'CheckLst' (#lcl)

# TCheckListBox

[Properties (by Name)] [Methods (by Name)] [Events (by Name)]

TCheckListBox implements a list box with check boxes for its items.

## Declaration

Source position: checklst.pas line 93

`type TCheckListBox = class(TCustomCheckListBox)`
`published`
`property Align: TAlign;` |  | Specifies the placement of the control on its Parent control.
`property AllowGrayed: Boolean;` |  | Indicates if the item can use the "grayed" (or unselectable) check box state.
`property Anchors: TAnchors;` |  | The set of anchor definitions for this control.
`property BidiMode: TBiDiMode;` |  | Indicates whether text controls use in bi-directional reading.
`property BorderSpacing: TControlBorderSpacing;` |  | Determines the inner and outer border spacing for this control.
`property BorderStyle: TBorderStyle;` |  | Indicates the border style displayed around the control.
`property Color: TColor;` |  | The background color for the control.
`property Columns: Integer;` |  | The number of visible columns displayed on the control.
`property Constraints: TSizeConstraints;` |  | Contains the minimum and maximum Width and Height for the control.
`property DragCursor: TCursor;` |  | The cursor shape shown during a drag operation.
`property DragMode: TDragMode;` |  | Determines how a drag operation is started for the control.
`property ExtendedSelect: Boolean;` |  | True when a contiguous range of items can be selected using Shift+Click. The default value is True.
`property Enabled: Boolean;` |  | Determines whether the control responds to mouse or keyboard input.
`property Font: TFont;` |  | The font to be used for text display in this control.
`property HeaderBackgroundColor: TColor;` |  | Color used to paint the background for Header items on the control.
`property HeaderColor: TColor;` |  | Color used for the text on a Header item.
`property IntegralHeight: Boolean;` |  | Not implemented: shrink the Height of the widget, so that it only shows fully visible rows.
`property Items: TStrings;` |  | The list of all items defined in the control.
`property ItemHeight: Integer;` |  | The default height for an item displayed in the list.
`property ItemIndex: Integer;` |  | Ordinal position for the currently selected item, -1 if none.
`property MultiSelect: Boolean;` |  | Allows selection of more than one item from the list.
`property Options: TListBoxOptions;` |  | Contains options enabled for the list box control.
`property ParentBidiMode: Boolean;` |  | Indicates whether the BiDiMode settings in the Parent control are used.
`property ParentColor: Boolean;` |  | Use the Color from the Parent control, when enabled.
`property ParentFont: Boolean;` |  | Indicates if the Font from the Parent control is used in the control.
`property ParentShowHint: Boolean;` |  | If True, the value of ShowHint for the control will be the same as the one from the Parent. Default is True.
`property PopupMenu: TPopupMenu;` |  | A context-sensitive menu that pops up when the right mouse button is clicked over this control.
`property ShowHint: Boolean;` |  | Enables Hint display for the control.
`property Sorted: Boolean;` |  | Determines whether the list entries are sorted in alphanumeric order.
`property Style: TListBoxStyle;` |  | Appearance of the list box (standard, owner-draw fixed, or owner-draw variable).
`property TabOrder: TTabOrder;` |  | Indicates the navigation order for the control when the user presses the Tab or Shift+Tab key.
`property TabStop: Boolean;` |  | Allows the user to navigate to / from the control by pressing the Tab or Shift+Tab keys.
`property TopIndex: Integer;` |  | Index of the first visible (or top-most) item.
`property Visible: Boolean;` |  | Allows the control, and all of its children, to be displayed or hidden.
`property OnChangeBounds: TNotifyEvent;` |  | Event handler signalled when the Bounds for the control have been changed.
`property OnClick: TNotifyEvent;` |  | Notification handler for mouse clicks.
`property OnClickCheck: TNotifyEvent;` |  | Event handler signalled when a check box in the control has been changed.
`property OnContextPopup: TContextPopupEvent;` |  | Invoked when a context-sensitive pop-up menu is requested.
`property OnDblClick: TNotifyEvent;` |  | Event handler signalled when a mouse double click occurs in the control.
`property OnDrawItem: TDrawItemEvent;` |  | Handler for painting of a list item in owner-draw mode.
`property OnDragDrop: TDragDropEvent;` |  | Event handler signalled when an object is dropped onto the control.
`property OnDragOver: TDragOverEvent;` |  | Event handler signalled when a control is dragged over the control instance.
`property OnEndDrag: TEndDragEvent;` |  | Event handler signalled for the end of a drag-drop operation.
`property OnEnter: TNotifyEvent;` |  | Event handler signalled when the control receives focus.
`property OnExit: TNotifyEvent;` |  | Event handler signalled when the control loses focus.
`property OnItemClick: TCheckListClicked; deprecated ;` |  | Deprecated. Event handler signalled when the check box state for a specific item has been changed.
`property OnKeyPress: TKeyPressEvent;` |  | Event handler signalled for character data entered by the user.
`property OnKeyDown: TKeyEvent;` |  | Event handler signalled for key down keyboard events.
`property OnKeyUp: TKeyEvent;` |  | Event handler signalled when a key up event has occurred for the control.
`property OnMeasureItem: TMeasureItemEvent;` |  | Handler invoked when the height for an item is needed.
`property OnMouseDown: TMouseEvent;` |  | Event handler signalled when a mouse down event is handled for the control.
`property OnMouseEnter: TNotifyEvent;` |  | Event handler signalled when the mouse pointer has entered the control.
`property OnMouseLeave: TNotifyEvent;` |  | Event handler signalled when the mouse pointer has left the control.
`property OnMouseMove: TMouseMoveEvent;` |  | Event handler signalled when the mouse pointer is moved in the control.
`property OnMouseUp: TMouseEvent;` |  | Event handler signalled when a mouse up event is handled for the control.
`property OnMouseWheel: TMouseWheelEvent;` |  | Event handler for mouse wheel turned.
`property OnMouseWheelDown: TMouseWheelUpDownEvent;` |  | Event handler signalled for a downward movement of the mouse wheel.
`property OnMouseWheelUp: TMouseWheelUpDownEvent;` |  | Event handler signalled for an upward movement of the mouse wheel.
`property OnMouseWheelHorz: TMouseWheelEvent;` |  | Event handler signalled for a horizontal movement of the mouse wheel.
`property OnMouseWheelLeft: TMouseWheelUpDownEvent;` |  | Event handler signalled for a leftward movement of the mouse wheel.
`property OnMouseWheelRight: TMouseWheelUpDownEvent;` |  | Event handler signalled for a rightward movement of the mouse wheel.
`property OnResize: TNotifyEvent;` |  | Notification handler for a resize of the control.
`property OnSelectionChange: TSelectionChangeEvent;` |  | Handler invoked when an item is selected in the control.
`property OnShowHint: TControlShowHintEvent;` |  | Event handler signalled when a hint window is displayed for the control.
`property OnStartDrag: TStartDragEvent;` |  | Event handler signalled for the start of a dragging operation.
`property OnUTF8KeyPress: TUTF8KeyPressEvent;` |  | Handler for a character entered by the user.
`end;`

## Inheritance

`TCheckListBox` |  | TCheckListBox implements a list box with check boxes for its items.
`TCustomCheckListBox` |  | The base class for TCheckListBox, a list box with check box items.
`TCustomListBox` |  | The base class for TListBox.
`TWinControl` |  | Implements a windowed control which can contain other child controls.
`TControl` |  | The base class for visible controls.
`TLCLComponent` |  | The base class for LCL components which have an associated widget.
`TComponent`
?
`TObject`

## Description

TCheckListBox is a TCustomCheckListBox descendant which implements a scrollable list box which displays check boxes for each of its items.

Use the Items property to define the caption for entries that appear in the control. Each of the Items can have a state of checked or unchecked (or "grayed" when AllowGrayed is set). Use the properties and methods such as Toggle, CheckAll, Checked, ItemEnabled, and State to maintain the items in the control.

It provides the scrolling, selection, and drawing styles inherited from the ancestor class. It also includes the ability to render its items as a check box, and to respond to mouse or keyboard events when an item is toggled.

Use the event handlers in the class to perform actions needed when one or more items are clicked or change their state value. Use OnItemClick to process item changes individually.

TCheckListBox sets the visibility for properties defined in the ancestor class.

## See also

TCustomCheckListBox |  | The base class for TCheckListBox, a list box with check box items.