Unit 'DBCtrls' Package
[Overview][Constants][Types][Classes][Procedures and functions][Index] [#lcl]

TDBComboBox

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

TDBComboBox - a data-aware version of TComboBox to allow selection of a value from a list of entries into a database field.

Declaration

Source position: dbctrls.pp line 783

type TDBComboBox = class(TCustomDBComboBox)

protected

  procedure DataChange(); override;

  

DataChange - updates the text if it has changed.

  procedure KeyPress(); override;

  

Applies standard keystrokes to the control.

  procedure UpdateData(); override;

  

Applies the changed value for the control to the field in its linked dataset.

published

  property Align: TAlign;

  

Specifies the placement of the control on its Parent control.

  property Anchors: TAnchors;

  

The set of anchor definitions for this control.

  property ArrowKeysTraverseList: Boolean;

  

Indicates if keyboard Arrow (or cursor) keys can be used to move through the list.

  property AutoComplete: Boolean;

  

Positions the list box using partial text matching.

  property AutoCompleteText: TComboBoxAutoCompleteText;

  

Options for the behavior of the Auto-Complete feature.

  property AutoDropDown: Boolean;

  

Indicates if the drop-down is automatically displayed when the control gets the input focus.

  property AutoSelect: Boolean;

  

Selects the entire content of the edit box when the control receives the focus.

  property AutoSize: Boolean;

  

Allows automatic adjustment of the size for the control, according to its content.

  property BiDiMode: TBiDiMode;

  

Customization (of text controls) in bidirectional reading environments.

  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 CharCase: TEditCharCase;

  

Indicates the case conversion applied to the value entered in the edit box for the control.

  property Color: TGraphicsColor;

  

The background color of the control.

  property Constraints: TSizeConstraints;

  

Contains the minimum and maximum Width and Height for the control.

  property DataField: string;

  

The name of the Field which provides the values displayed in the control.

  property DataSource: TDataSource;

  

Provides access to the dataset with content for the control.

  property DoubleBuffered: Boolean;

  

Allows to reduce flicker in the painting of the control.

  property DragCursor: TCursor;

  

The cursor shape shown while the control is dragged.

  property DragKind: TDragKind;

  

The operation when the control is dragged - Drag or Dock.

  property DragMode: TDragMode;

  

Allows the user to drag the control.

  property DropDownCount: Integer;

  

The maximum number of Items visible in the drop-down list for the control.

  property Enabled: Boolean;

  

Determines whether the control reacts on mouse or keyboard input.

  property Font: TFont;

  

The font to be used for text display in this control.

  property ItemHeight: Integer;

  

The default height of an item in the drop-down for the control.

  property Items: TStrings;

  

The list of items displayed in the combo-box control.

  property ItemWidth: Integer;

  

The minimum width of the items in the drop-down list.

  property MaxLength: Integer;

  

The maximum length for text entered in the edit box for the control.

  property OnChange: TNotifyEvent;

  

Event handler signalled for user changes to the text in the edit box.

  property OnChangeBounds: TNotifyEvent;

  

Event handler signalled when the Bounds of the control have been changed.

  property OnClick: TNotifyEvent;

  

Notification handler for mouse clicks.

  property OnCloseUp: TNotifyEvent;

  

Handler invoked when the drop-down list closes.

  property OnContextPopup: TContextPopupEvent;

  

Invoked when a context-sensitive pop-up menu is requested.

  property OnDblClick: TNotifyEvent;

  

Event Handler for double mouse clicks.

  property OnDragDrop: TDragDropEvent;

  

This handler determines the action on an drop onto this control, in a drag-drop operation.

  property OnDragOver: TDragOverEvent;

  

Event handler for a control being dragged over this control.

  property OnDrawItem: TDrawItemEvent;

  

Handler for special painting of an item (in owner-draw mode).

  property OnDropDown: TNotifyEvent;

  

Handler invoked when the list has dropped down.

  property OnEditingDone: TNotifyEvent;

  

Event handler signalled when editing is done.

  property OnEndDrag: TEndDragEvent;

  

Notification handler for the end of a drag operation.

  property OnEnter: TNotifyEvent;

  

Handler for control receiving the focus.

  property OnExit: TNotifyEvent;

  

Handler for control loosing the focus; This is a good place for checking the finished user input.

  property OnKeyDown: TKeyEvent;

  

Event handler signalled when a key is down while the control has focus.

  property OnKeyPress: TKeyPressEvent;

  

Event handler signalled when a key is pressed while the control has focus.

  property OnKeyUp: TKeyEvent;

  

Event handler signalled when when a key is released while the control has focus.

  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 for mouse movement within 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 for downward movement of mouse wheel.

  property OnMouseWheelUp: TMouseWheelUpDownEvent;

  

Event handler for upward movement of the mouse wheel.

  property OnSelect: TNotifyEvent;

  

Handler invoked when an item is selected.

  property OnStartDrag: TStartDragEvent;

  

Event handler for the start of a dragging operation.

  property OnUTF8KeyPress: TUTF8KeyPressEvent;

  

Handler for a character entered by the user.

  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 ParentDoubleBuffered: Boolean;

  

Value for the DoubleBuffered property in a Parent control.

  property ParentFont: Boolean;

  

If True, the Font of the control will be the same as the one from the Parent. Default is True.

  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 ReadOnly: Boolean;

  

Indicates if the control is prevented from changing the field value in its linked dataset.

  property ShowHint: Boolean;

  

Enables Hint display for the control.

  property Sorted: Boolean;

  

Determines whether the list entries are sorted in alphanumeric order.

  property Style: TComboBoxStyle;

  

Appearance and behavior of the combo-box.

  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 Visible: Boolean;

  

Indicates if the control is visible on its parent.

end;

Inheritance

TDBComboBox

  

TDBComboBox - a data-aware version of TComboBox to allow selection of a value from a list of entries into a database field.

|

TCustomDBComboBox

  

TCustomDBComboBox is a data-aware combo-box for displaying information from a database.

|

TCustomComboBox

  

The base class for combo-box components.

|

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.

|

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

TCustomDBComboBox

  

TCustomDBComboBox is a data-aware combo-box for displaying information from a database.

How To Use Data-aware Controls

  

HowToUseDataAwareControls - Hints for accessing databases.