[Overview][Constants][Types][Classes][Procedures and functions][Index] Reference for unit 'DbCtrls' (#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 708

type TDBComboBox = class(TCustomDBComboBox) end;

protected

  procedure DataChange(); override;

  

DataChange - updates the text if it has changed

  procedure KeyDown(); override;

  procedure KeyPress(); override;

  procedure Select; override;

  procedure UpdateData(); override;

  

UpdateData - copies the new data via the datalink

published

  property Anchors: TAnchors;

  

The set of anchor definitions for this control.

  property ArrowKeysTraverseList: Boolean;

  

Allows the operator to use also the keyboard Arrow keys to move through the list.

  property AutoDropDown: Boolean;

  

Makes the drop-down list appear as soon as the user starts entering text.

  property AutoComplete: Boolean;

  property AutoSize: Boolean;

  

Allows to automatically adjust the size of the control, according to its content.

  property BiDiMode: TBiDiMode;

  property BorderSpacing: TControlBorderSpacing;

  

Determines the inner and outer border spacing for this control.

  property BorderStyle: TBorderStyle;

  property CharCase: TEditCharCase;

  property Color: TColor;

  

The background color of the control.

  property DataField: string;

  

The name (as a string) of the Feild whose data are to be linked to the ComboBox

  property DataSource: TDataSource;

  

The identity of the DataSource to which the ComboBox is attached

  property DragCursor: TCursor;

  

The cursor shape shown while the control is dragged.

  property DragMode: TDragMode;

  

Allows the user to drag the control.

  property DropDownCount: Integer;

  

The height of the drop-down list, measured in number of items.

  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 a list item.

  property Items: TStrings;

  

The list of all items in the control.

  property ItemWidth: Integer;

  

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

  property MaxLength: Integer;

  

The maximum length of user input.

  property OnChange: TNotifyEvent;

  

Event handler for user changed text in the edit box.

  property OnChangeBounds: TNotifyEvent;

  

Event handler for a change of the Bounds of the control.

  property OnClick: TNotifyEvent;

  

Notification handler for mouse clicks.

  property OnCloseUp: TNotifyEvent;

  

Handler invoked when the drop-down list closes.

  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 when editing is done.

  property OnEndDrag: TEndDragEvent;

  

Notification handler for the end of a dragging 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;

  

Handler for keyboard key pressed.

  property OnKeyPress: TKeyPressEvent;

  

Handler for a character entered by the user.

  property OnKeyUp: TKeyEvent;

  

Handler for keyboard key released.

  property OnMouseDown: TMouseEvent;

  

Event handler for mouse button going down.

  property OnMouseEnter: TNotifyEvent;

  property OnMouseLeave: TNotifyEvent;

  property OnMouseMove: TMouseMoveEvent;

  

Event handler for mouse movement within the control.

  property OnMouseUp: TMouseEvent;

  

Event handler for mouse button going up.

  property OnMouseWheel: TMouseWheelEvent;

  property OnMouseWheelDown: TMouseWheelUpDownEvent;

  property OnMouseWheelUp: TMouseWheelUpDownEvent;

  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;

  property ParentColor: Boolean;

  

If true, the Color of the control will be the same as the one from the Parent. Default is true.

  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 ReadOnly: Boolean;

  

Disallows entry of free text.

  property ShowHint: Boolean;

  

Enables the Hint display.

  property Sorted: Boolean;

  

Determines whether the list entries are sorted.

  property Style: TComboBoxStyle;

  

Appearance and behaviour of the ComboBox (static/drop-down, owner-draw...).

  property TabOrder: TTabOrder;

  

Determines the sequence of controls, reachable when the user presses the Tab key.

  property TabStop: Boolean;

  

Allows the user to navigate to this control, by pressing the Tab key.

  property Visible: Boolean;

  

Allows to show or hide the control, and all of its children.

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 - a Data-aware Combo Box for displaying information from a Database

|

TCustomComboBox

  

The base class for ComboBox components.

|

TWinControl

  

The base class for controls which can contain other (child) controls.

|

TControl

  

The base class for visible controls.

|

TLCLComponent

  

The base class for LCL components associated with widgets.

|

TComponent

?

TObject

Description

TDBComboBox has properties similar to TComboBox and TCustomComboBox. It consists of an Edit Box which is th eData-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.

So for 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

HowToUseDataAwareControls

  

HowToUseDataAwareControls - Hints for accessing databases

The latest version of this document can be found at lazarus-ccr.sourceforge.net.