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TCheckBox class

In unit StdCtrls

A label with a box which can contain a check mark.

Declaration

pascal
TCheckBox = class(TCustomCheckBox)

Inheritance

  1. TCheckBox
  2. TCustomCheckBox
  3. TButtonControl
  4. TWinControl
  5. TControl
  6. TLCLComponent
  7. TComponent
  8. TPersistent
  9. TObject

Description

TCheckBox is a TCustomCheckBox descendant which implements a check box component. A check box control allows the user to choose the state for the control independent of other check box controls (unlike a radio button).

The State property contains the checked, unchecked, or grayed state for the control. The AllowGrayed property indicates if the grayed state is allowed in the control; otherwise only checked and unchecked are used. The Checked property allows the value in State to be updated by setting a Boolean value that indicates if the control is check or unchecked.

See also

Properties

ActionpublishedThe Action associated with the control.
AlignpublishedSpecifies the placement of the control on its Parent control.
AlignmentpublishedIndicates the alignment for the caption text in the control.
AllowGrayedpublishedAllows the check box to use a "grayed" state.
AnchorspublishedThe set of anchor definitions for this control.
AutoSizepublishedAllows automatic adjustment of the size for the control, according to its content.
BidiModepublishedIndicates whether text controls use in bi-directional reading.
BorderSpacingpublishedDetermines the inner and outer border spacing for this control.
CaptionpublishedThe text displayed for the control.
CheckedpublishedIndicates the checked state for the control as a Boolean value.
ColorpublishedThe background color for the control.
ConstraintspublishedContains the minimum and maximum Width and Height for the control.
DoubleBufferedpublishedWhen enabled, it reduces flicker when the control is painted.
DragCursorpublishedThe cursor shape shown during a drag operation.
DragKindpublishedIndicates the action performed for a drag operation: drag-and-drop or drag-and-dock.
DragModepublishedDetermines how a drag operation is started for the control.
EnabledpublishedDetermines whether the control responds to mouse or keyboard input.
FontpublishedThe font to be used for text display in this control.
HintpublishedThe text to show in the Hint window for the control.
ParentColorpublishedUse the Color from the Parent control, when enabled.
ParentDoubleBufferedpublishedValue for the DoubleBuffered property in a Parent control.
ParentFontpublishedIndicates if the Font from the Parent control is used in the control.
ParentShowHintpublishedIf True, the value of ShowHint for the control will be the same as the one from the Parent. Default is True.
ParentBidiModepublishedIndicates whether the BiDiMode settings in the Parent control are used.
PopupMenupublishedA context-sensitive menu that pops up when the right mouse button is clicked over this control.
ShowHintpublishedEnables Hint display for the control.
StatepublishedThe check, unchecked, or grayed state for the control.
TabOrderpublishedIndicates the navigation order for the control when the user presses the Tab or Shift+Tab key.
TabStoppublishedEnables keyboard navigation using the Tab or Shift+Tab keys.
VisiblepublishedAllows the control, and all of its children, to be displayed or hidden.

Methods

CreatepublicConstructor for the class instance.

Events

OnChangepublishedEvent handler signalled when the button control is clicked.
OnChangeBoundspublishedEvent handler signalled when the Bounds for the control have been changed.
OnClickpublishedNotification handler for mouse clicks.
OnContextPopuppublishedInvoked when a context-sensitive pop-up menu is requested.
OnDragDroppublishedEvent handler signalled when an object is dropped onto the control.
OnDragOverpublishedEvent handler signalled when a control is dragged over the control instance.
OnEditingDonepublishedEvent handler signalled when editing is completed for the control.
OnEndDragpublishedEvent handler signalled for the end of a drag-drop operation.
OnEnterpublishedEvent handler signalled when the control receives focus.
OnExitpublishedEvent handler signalled when the control loses focus.
OnKeyPresspublishedEvent handler signalled for character data entered by the user.
OnKeyDownpublishedEvent handler signalled for key down keyboard events.
OnKeyUppublishedEvent handler signalled when a key up event has occurred for the control.
OnMouseDownpublishedEvent handler signalled when a mouse down event is handled for the control.
OnMouseEnterpublishedEvent handler signalled when the mouse pointer has entered the control.
OnMouseLeavepublishedEvent handler signalled when the mouse pointer has left the control.
OnMouseMovepublishedEvent handler signalled when the mouse pointer is moved in the control.
OnMouseUppublishedEvent handler signalled when a mouse up event is handled for the control.
OnMouseWheelpublishedEvent handler for mouse wheel turned.
OnMouseWheelDownpublishedEvent handler signalled for a downward movement of the mouse wheel.
OnMouseWheelUppublishedEvent handler signalled for an upward movement of the mouse wheel.
OnResizepublishedNotification handler for a resize of the control.
OnStartDragpublishedEvent handler signalled for the start of a dragging operation.
OnUTF8KeyPresspublishedHandler for a character entered by the user.

Inherited

From TCustomCheckBox (18)

ApplyChanges Click CreateParams DialogChar DoClickOnChange GetChecked GetControlClassDefaultSize InitializeWnd Loaded RealSetText RetrieveState SetChecked ShortCut ShortCutKey2 TextChanged Toggle WSRegisterClass WSSetText

From TButtonControl (3)

ClicksDisabled DoOnChange GetActionLinkClass

From TWinControl (228)

AddControl AdjustClientRect AlignControls AllAutoSized AutoAdjustLayout AutoSizeDelayed AutoSizeDelayedHandle AutoSizeDelayedReport AutoSizePhases BeginUpdateBounds BorderStyle BorderWidth BoundsLockCount BroadCast Brush BrushCreated CachedClientHeight CachedClientWidth CalculatePreferredSize CanFocus CanSetFocus CanTab ChangeScale ChildClassAllowed ChildHandlesCreated ChildKey ChildSizing ClientRectNeedsInterfaceUpdate CMBiDiModeChanged CMBorderChanged CMDoubleBufferedChanged CMEnabledChanged CMEnter CMExit CMParentDoubleBufferedChanged CMShowHintChanged CMShowingChanged CMVisibleChanged CNChar CNKeyDown CNKeyUp CNSysKeyDown CNSysKeyUp ContainsControl ControlAtPos ControlCount ControlKeyDown ControlKeyUp Controls ControlsAligned CreateBrush CreateDockManager CreateHandle CreateParented CreateParentedControl CreateSubClass CreateWnd CustomAlignInsertBefore CustomAlignPosition DefaultHandler DefWndProc DesignerDeleting Destroy DestroyHandle DestroyWnd DisableAlign DoAddDockClient DoAdjustClientRectChange DoAlignChildControls DoAllAutoSize DoAutoSize DoChildSizingChange DockClientCount DockClients DockDrop DockManager DockOver DockSite DoConstraintsChange DoDockClientMsg DoDockOver DoDragMsg DoEnter DoExit DoFlipChildren DoFloatMsg DoGetDockCaption DoKeyDownBeforeInterface DoKeyPress DoKeyUpBeforeInterface DoRemainingKeyDown DoRemainingKeyUp DoRemoveDockClient DoSendBoundsToInterface DoSendShowHideToInterface DoSetBounds DoUnDock DoUndockClientMsg DoUTF8KeyPress EnableAlign EndUpdateBounds EraseBackground FinalizeWnd FindChildControl FindNextControl FixDesignFontsPPIWithChildren FixupTabList FlipChildren Focused FontChanged FormEndUpdated GetAdjustedLogicalClientRect GetBorderStyle GetChildren GetChildrenRect GetClientOrigin GetClientRect GetControlIndex GetControlOrigin GetDeviceContext GetDockCaption GetEnumeratorControls GetEnumeratorControlsReverse GetMouseCapture GetParentHandle GetPreferredSizeClientFrame GetSiteInfo GetTabOrderList GetTextLen GetTopParentHandle Handle HandleAllocated HandleNeeded InsertControl IntfGetDropFilesTarget IntfUTF8KeyPress Invalidate InvalidateBoundsRealized InvalidateClientRectCache InvalidatePreferredChildSizes IsClientHeightStored IsClientWidthStored IsControlMouseMsg IsFlipped IsResizing IsSpecialSubControl KeyDown KeyDownAfterInterface KeyDownBeforeInterface KeyPress KeyUp KeyUpAfterInterface KeyUpBeforeInterface LockRealizeBounds MainWndProc NotifyControls OnAlignInsertBefore OnAlignPosition OnDockDrop OnDockOver OnGetDockCaption OnGetSiteInfo OnUnDock PaintControls PaintHandler PaintTo PaintWindow ParentFormHandleInitialized ParentHandlesAllocated ParentWindow PerformTab RealGetText ReAlign RealizeBounds RealizeBoundsRecursive ReloadDockedControl RemoveControl RemoveFocus Repaint ScaleBy ScaleControls ScrollBy ScrollBy_WS SelectFirst SelectNext SendDialogChar SendMoveSizeMessages SetBorderStyle SetBounds SetChildZPosition SetColor SetControlIndex SetDockManager SetFocus SetShape SetTempCursor ShowControl Showing UnlockRealizeBounds Update UpdateControlState UpdateDockCaption UpdateShowing UseDockManager UTF8KeyPress VisibleDockClientCount WindowHandle WMChar WMContextMenu WMDestroy WMEnter WMEraseBkgnd WMExit WMKeyDown WMKeyUp WMKillFocus WMMove WMNotify WMPaint WMSetFocus WMShowWindow WMSize WMSysChar WMSysKeyDown WMSysKeyUp WMWindowPosChanged WndProc WriteLayoutDebugReport

From TControl (324)

AccessibleDescription AccessibleName AccessibleRole AccessibleValue ActionChange ActionLink ActiveDefaultControlChanged AddHandler AddHandlerOnBeforeDestruction AddHandlerOnChangeBounds AddHandlerOnEnabledChanged AddHandlerOnEnabledChanging AddHandlerOnKeyDown AddHandlerOnMouseWheel AddHandlerOnResize AddHandlerOnVisibleChanged AddHandlerOnVisibleChanging AdjustSize AnchorAsAlign AnchorClient AnchoredControlCount AnchoredControls AnchorHorizontalCenterTo AnchorParallel AnchorSame AnchorSide AnchorSideBottom AnchorSideChanged AnchorSideLeft AnchorSideRight AnchorSideTop AnchorToCompanion AnchorToNeighbour AnchorVerticalCenterTo AssignTo AutoSizing AutoSizingAll AutoSizingLockCount BaseBounds BaseParentClientSize BeforeDestruction BeforeDragStart BeginAutoDrag BeginAutoSizing BeginDrag BoundsChanged BoundsRect BoundsRectForNewParent BringToFront CalculateDockSizes CanAutoSize CaptureChanged CaptureMouseButtons ChangeBounds Changed CheckChildClassAllowed CheckNewParent CheckOnChangeBounds ClientHeight ClientOrigin ClientRect ClientToParent ClientToScreen ClientWidth CMChanged CMCursorChanged CMHintShow CMHitTest CMMouseEnter CMMouseLeave CMParentBiDiModeChanged CMParentColorChanged CMParentFontChanged CMParentShowHintChanged CMSysFontChanged CMTextChanged CNPreferredSizeChanged ColorIsStored ConstrainedResize ControlFontClass ControlOrigin ControlState ControlStyle ControlToScreen CreateAccessibleObject CreateControlBorderSpacing CreateFloatingDockSite Cursor DblClick DefineProperties DesktopFont DisableAutoSizing DoAutoAdjustLayout DoBorderSpacingChange DoCallKeyEventHandler DoCallMouseWheelEventHandler DoCallNotifyHandler Dock Docked DockOrientation DockTrackNoTarget DoContextPopup DoDock DoEndDock DoEndDrag DoFixDesignFontPPI DoMouseDown DoMouseUp DoMouseWheel DoMouseWheelDown DoMouseWheelHorz DoMouseWheelLeft DoMouseWheelRight DoMouseWheelUp DoOnChangeBounds DoOnParentHandleDestruction DoOnResize DoOnShowHint DoScaleFontPPI DoStartDock DoStartDrag DragCanceled DragDrop Dragging DragOver EditingDone EnableAutoSizing EnabledChanged EnabledChanging EndAutoSizing EndDrag ExecuteCancelAction ExecuteDefaultAction FindSubComponent FixDesignFontsPPI Floating FloatingDockSiteClass ForeignAnchorSideChanged FormIsUpdating GetAccessibleObject GetAction GetAnchorsDependingOnParent GetCachedText GetCanvasScaleFactor GetChildAccessibleObjectAtPos GetClientScrollOffset GetColorResolvingParent GetCursor GetDefaultColor GetDefaultDockCaption GetDefaultHeight GetDefaultWidth GetDockEdge GetDragImages GetEnabled GetFloating GetFloatingDockSiteClass GetLogicalClientRect GetMousePosFromMessage GetPalette GetParentBackground GetParentComponent GetPopupMenu GetPreferredSize GetRGBColorResolvingParent GetScrolledClientRect GetSelectedChildAccessibleObject GetSidePosition GetTextBuf GetTopParent HandleObjectShouldBeVisible HasHelp HasParent Height HeightIsAnchored HelpContext HelpKeyword HelpType Hide HostDockSite InitiateAction InvalidateControl InvalidatePreferredSize IsAParentAligning IsBorderSpacingInnerBorderStored IsCaptionStored IsControl IsControlVisible IsEnabled IsParentColor IsParentFont IsParentOf IsProcessingPaintMsg IsRightToLeft IsVisible Left LMCaptureChanged LoadedAll LRDockWidth ManualDock ManualFloat MouseCapture MouseDown MouseEnter MouseInClient MouseLeave MouseMove MouseUp Notification OnConstrainedResize OnDblClick OnEndDock OnMouseWheelHorz OnMouseWheelLeft OnMouseWheelRight OnQuadClick OnShowHint OnStartDock OnTripleClick Parent ParentBackground ParentDestroyingHandle ParentFontChanged ParentToClient Perform PositionDockRect QuadClick ReadBounds ReadState Refresh RemoveAllHandlersOfObject RemoveHandler RemoveHandlerOnBeforeDestruction RemoveHandlerOnChangeBounds RemoveHandlerOnEnabledChanged RemoveHandlerOnEnabledChanging RemoveHandlerOnKeyDown RemoveHandlerOnMouseWheel RemoveHandlerOnResize RemoveHandlerOnVisibleChanged RemoveHandlerOnVisibleChanging ReplaceDockedControl RequestAlign Resize Scale96ToFont Scale96ToForm Scale96ToScreen ScaleConstraints ScaleDesignToForm ScaleFontsPPI ScaleFontTo96 ScaleFontToScreen ScaleFormTo96 ScaleFormToDesign ScaleScreenTo96 ScaleScreenToFont ScreenToClient ScreenToControl SendToBack SessionProperties SetAction SetAlign SetAnchors SetAutoSize SetBiDiMode SetBoundsKeepBase SetCursor SetDragMode SetEnabled SetHint SetInitialBounds SetName SetParent SetParentBackground SetParentBiDiMode SetParentComponent SetTextBuf SetVisible SetZOrder ShouldAutoAdjust Show ShowHelp TBDockHeight Text Top TripleClick UndockHeight UndockWidth UpdateAnchorRules UpdateBaseBounds UpdateMouseCursor UpdateRolesForForm UseRightToLeftAlignment UseRightToLeftReading UseRightToLeftScrollBar VisibleChanged VisibleChanging Width WidthIsAnchored WindowProc WMCancelMode WMLButtonDBLCLK WMLButtonDown WMLButtonQuadCLK WMLButtonTripleCLK WMLButtonUp WMMButtonDBLCLK WMMButtonDown WMMButtonQuadCLK WMMButtonTripleCLK WMMButtonUp WMMouseHWheel WMMouseMove WMMouseWheel WMRButtonDBLCLK WMRButtonDown WMRButtonQuadCLK WMRButtonTripleCLK WMRButtonUp WMXButtonDBLCLK WMXButtonDown WMXButtonQuadCLK WMXButtonTripleCLK WMXButtonUp

From TLCLComponent (6)

DecLCLRefCount GetWSComponentClass IncLCLRefCount LCLRefCount NewInstance WidgetSetClass

From TComponent (64)

_AddRef _Release CanObserve ChangeName ComObject ComponentCount ComponentIndex Components ComponentState ComponentStyle DesignInfo DestroyComponents Destroying ExecuteAction FindComponent FreeNotification FreeOnRelease GetChildOwner GetChildParent GetDeltaStreams GetEnumerator GetIDsOfNames GetNamePath GetObservers GetOwner GetTypeInfo GetTypeInfoCount iicrGetComponent InsertComponent Invoke IsImplementorOf Loading Name ObserverAdded Observers OnGetDeltaStreams Owner PaletteCreated QueryInterface ReadDeltaState ReadDeltaStream ReferenceInterface RemoveComponent RemoveFreeNotification RemoveFreeNotifications SafeCallException SetAncestor SetChildOrder SetDesigning SetDesignInstance SetInline SetSubComponent Tag ToString TToStringNameMode UpdateAction Updated UpdateRegistry Updating ValidateContainer ValidateInsert ValidateRename VCLComObject WriteState

From TPersistent (4)

Assign FPOAttachObserver FPODetachObserver FPONotifyObservers

From TObject (35)

AfterConstruction CheckDisposed ClassInfo ClassName ClassNameIs ClassParent ClassType CleanupInstance DefaultHandlerStr Dispatch DispatchStr Disposed DisposeOf Equals FieldAddress Free FreeInstance GetDisposed GetHashCode GetInterface GetInterfaceByStr GetInterfaceEntry GetInterfaceEntryByStr GetInterfaceTable GetInterfaceWeak GetLastCastErrorInfo InheritsFrom InitInstance InstanceSize MethodAddress MethodName QualifiedClassName StringMessageTable SystemHasExtendedRTTI UnitName

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.