Sign in Join
FPDoc Onlineexperiment

TDBComboBox class

In unit DBCtrls

TDBComboBox is a data-aware version of TComboBox which allows selection of a value from a list of entries into a database field.

Declaration

pascal
TDBComboBox = class(TCustomDBComboBox)

Inheritance

  1. TDBComboBox
  2. TCustomDBComboBox
  3. TCustomComboBox
  4. TWinControl
  5. TControl
  6. TLCLComponent
  7. TComponent
  8. TPersistent
  9. TObject

Description

TDBComboBox has properties similar to TComboBox and TCustomComboBox. It consists of an Edit Box which is the Data-aware part of the component, and a drop-down list box.

In a typical application a user would be presented with the drop-down list, would make a selection and then this would appear in the edit box and become the data value for that cell in the database.

As an example, a list of countries might be presented, and the selected value from the list would be used to populate the appropriate field ('Country') in that record of the database.

See also

Properties

AlignpublishedSpecifies the placement of the control on its Parent control.
AnchorspublishedThe set of anchor definitions for this control.
ArrowKeysTraverseListpublishedIndicates if keyboard Arrow (or cursor) keys can be used to move through the list.
AutoCompletepublishedPositions the list box using partial text matching.
AutoCompleteTextpublishedOptions for the behavior of the Auto-Complete feature.
AutoDropDownpublishedIndicates if the drop-down is automatically displayed when the control gets the input focus.
AutoSelectpublishedSelects the entire content of the edit box when the control receives the focus.
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.
BorderStylepublishedIndicates the border style displayed around the control.
CharCasepublishedIndicates the case conversion applied to the value entered in the edit box for the control.
ColorpublishedThe background color for the control.
ConstraintspublishedContains the minimum and maximum Width and Height for the control.
DataFieldpublishedThe name of the Field which provides the values displayed in the control.
DataSourcepublishedProvides access to the dataset with content 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.
DropDownCountpublishedThe maximum number of Items visible in the drop-down list for the control.
EnabledpublishedDetermines whether the control responds to mouse or keyboard input.
FontpublishedThe font to be used for text display in this control.
ItemHeightpublishedThe default height of an item in the drop-down for the control.
ItemspublishedThe list of items displayed in the combo-box control.
ItemWidthpublishedThe minimum width of the items in the drop-down list.
MaxLengthpublishedThe maximum length for text entered in the edit box for the control.
ParentBiDiModepublishedIndicates whether the BiDiMode settings in the Parent control are used.
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.
PopupMenupublishedA context-sensitive menu that pops up when the right mouse button is clicked over this control.
ReadOnlypublishedIndicates if the control is prevented from changing the field value in its linked dataset.
ShowHintpublishedEnables Hint display for the control.
SortedpublishedDetermines whether the list entries are sorted in alphanumeric order.
StylepublishedControls the appearance and behavior for the combo-box.
TabOrderpublishedIndicates the navigation order for the control when the user presses the Tab or Shift+Tab key.
TabStoppublishedAllows the user to navigate to / from the control by pressing the Tab or Shift+Tab keys.
VisiblepublishedIndicates if the control is visible on its parent.

Methods

DataChangeprotectedDataChange - updates the text if it has changed.
KeyPressprotectedApplies standard keystrokes to the control.
UpdateDataprotectedApplies the changed value for the control to the field in its linked dataset.

Events

OnChangepublishedEvent handler signalled for user changes to the text in the edit box.
OnChangeBoundspublishedEvent handler signalled when the Bounds for the control have been changed.
OnClickpublishedNotification handler for mouse clicks.
OnCloseUppublishedHandler invoked when the drop-down list closes.
OnContextPopuppublishedInvoked when a context-sensitive pop-up menu is requested.
OnDblClickpublishedEvent handler signalled when a mouse double click occurs in the control.
OnDragDroppublishedEvent handler signalled when an object is dropped onto the control.
OnDragOverpublishedEvent handler signalled when a control is dragged over the control instance.
OnDrawItempublishedHandler for special painting of an item (in owner-draw mode).
OnDropDownpublishedHandler invoked when the list has dropped down.
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.
OnKeyDownpublishedEvent handler signalled when a key is down while the control has focus.
OnKeyPresspublishedEvent handler signalled when a key is pressed while the control has focus.
OnKeyUppublishedEvent handler signalled when when a key is released while the control has focus.
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.
OnSelectpublishedHandler invoked when an item is selected.
OnStartDragpublishedEvent handler signalled for the start of a dragging operation.
OnUTF8KeyPresspublishedHandler for a character entered by the user.

Inherited

From TCustomDBComboBox (22)

Change CloseUp Create Destroy DetectedEvents DoEdit DoMouseWheel DoOnChange DoOnCloseUp DoOnSelect EditingDone ExecuteAction Field ItemIndex KeyDown LMDeferredEdit Notification Select Text UpdateAction UpdateRecord WndProc

From TCustomComboBox (60)

AddHistoryItem AddItem AdjustDropDown AutoSelected CanShowEmulatedTextHint Canvas Clear ClearSelection CMWantSpecialKey CreateParams DestroyWnd DoAutoAdjustLayout DoAutoCompleteSelect DoEnter DoExit DrawItem DropDown DroppedDown EmulatedTextHintStatus GetControlClassDefaultSize GetItemCount GetItemHeight GetItemIndex GetItems GetMaxLength GetSelLength GetSelStart GetSelText InitializeWnd IntfGetItems KeyUp KeyUpAfterInterface LMChanged MatchListItem MeasureItem MouseUp OnGetItems OnMeasureItem RealGetText RealSetText SelectAll SelectItem SelLength SelStart SelText SetDropDownCount SetDroppedDown SetItemHeight SetItemIndex SetItems SetMaxLength SetSelLength SetSelStart SetSelText SetSorted SetStyle ShouldAutoAdjust TextHint UTF8KeyPress WSRegisterClass

From TWinControl (219)

AddControl AdjustClientRect AlignControls AllAutoSized AutoAdjustLayout AutoSizeDelayed AutoSizeDelayedHandle AutoSizeDelayedReport AutoSizePhases BeginUpdateBounds 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 DestroyHandle DialogChar DisableAlign DoAddDockClient DoAdjustClientRectChange DoAlignChildControls DoAllAutoSize DoAutoSize DoChildSizingChange DockClientCount DockClients DockDrop DockManager DockOver DockSite DoConstraintsChange DoDockClientMsg DoDockOver DoDragMsg 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 KeyDownAfterInterface KeyDownBeforeInterface KeyUpBeforeInterface Loaded LockRealizeBounds MainWndProc NotifyControls OnAlignInsertBefore OnAlignPosition OnDockDrop OnDockOver OnGetDockCaption OnGetSiteInfo OnUnDock PaintControls PaintHandler PaintTo PaintWindow ParentFormHandleInitialized ParentHandlesAllocated ParentWindow PerformTab 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 VisibleDockClientCount WindowHandle WMChar WMContextMenu WMDestroy WMEnter WMEraseBkgnd WMExit WMKeyDown WMKeyUp WMKillFocus WMMove WMNotify WMPaint WMSetFocus WMShowWindow WMSize WMSysChar WMSysKeyDown WMSysKeyUp WMWindowPosChanged WriteLayoutDebugReport WSSetText

From TControl (323)

AccessibleDescription AccessibleName AccessibleRole AccessibleValue Action 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 Caption CaptureChanged CaptureMouseButtons ChangeBounds Changed CheckChildClassAllowed CheckNewParent CheckOnChangeBounds Click 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 DoBorderSpacingChange DoCallKeyEventHandler DoCallMouseWheelEventHandler DoCallNotifyHandler Dock Docked DockOrientation DockTrackNoTarget DoContextPopup DoDock DoEndDock DoEndDrag DoFixDesignFontPPI DoMouseDown DoMouseUp DoMouseWheelDown DoMouseWheelHorz DoMouseWheelLeft DoMouseWheelRight DoMouseWheelUp DoOnChangeBounds DoOnParentHandleDestruction DoOnResize DoOnShowHint DoScaleFontPPI DoStartDock DoStartDrag DragCanceled DragDrop Dragging DragOver EnableAutoSizing EnabledChanged EnabledChanging EndAutoSizing EndDrag ExecuteCancelAction ExecuteDefaultAction FindSubComponent FixDesignFontsPPI Floating FloatingDockSiteClass ForeignAnchorSideChanged FormIsUpdating GetAccessibleObject GetAction GetActionLinkClass 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 Hint 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 OnConstrainedResize OnEndDock OnMouseWheelHorz OnMouseWheelLeft OnMouseWheelRight OnQuadClick OnResize 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 Show ShowHelp TBDockHeight TextChanged 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 (62)

_AddRef _Release CanObserve ChangeName ComObject ComponentCount ComponentIndex Components ComponentState ComponentStyle DesignInfo DestroyComponents Destroying 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 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.