TCustomDBComboBox

type TCustomDBComboBox = class(TCustomComboBox)

protected

  function DoEdit; virtual;

Performs LCL deferred edit messages for events detected in the control.

  procedure DoOnCloseUp; virtual;

Performs actions to close the drop down for the combo-box.

  procedure DoOnSelect; virtual;

Calls Select to trigger the OnSelect event handler.

  procedure DoOnChange; virtual;

Calls Change to trigger the OnChange event handler.

  procedure LMDeferredEdit(); message;

Implements the LCL message for a deferred edit.

  property DetectedEvents: Word; [r]

Deferred messages pending for the control.

  procedure CloseUp; override;

Sets deferred events when the drop down for the combo-box is closed.

  procedure Select; override;

Checks for the DBCBEVENT_SELECT message in the control.

  procedure DataChange(); virtual; abstract;

DataChange - updates any changes in text.

  function DoMouseWheel(); override;

Checks for mouse wheel events in the control.

  procedure Notification(); override;

Notification handler for insertion or deletion of components in the control.

  procedure Change; override;

Change -if there has been a change to the data the link must be notified.

  procedure KeyDown(); override;

Performs actions needed to apply the key down event.

  procedure UpdateData(); virtual; abstract;

UpdateData - implements any pending changes in the data.

  procedure UpdateRecord;

Updates the record in the linked dataset with the value for the control.

  procedure WndProc(); override;

Handles cut, copy and paste window messages for the control.

public

  constructor Create(); override;

Constructor for the class instance.

  destructor Destroy; override;

Destructor for the class instance.

  function ExecuteAction(); override;

Provides support for TBasicAction in the control.

  function UpdateAction(); override;

Updates the specified action to reflect the current state in the linked dataset.

  procedure EditingDone; override;

Updates data through the link, then calls inherited EditingDone.

  property Field: TField; [r]

Contains the field definition from the linked dataset.

  property Text: TCaption;

The value in the edit box for the control.

  property ItemIndex: Integer;

The index of the currently selected item, or -1 if none is selected.

  property DataField: string; [rw]

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

  property DataSource: TDataSource; [rw]

Provides access to the dataset with content for the control.

  property ReadOnly: Boolean; [rw]

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

end;

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.

TComponent,IUnknown,IInterfaceComponentReference

TPersistent,IFPObserved

TObject

TDBComboBox

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

TDBLookupComboBox

TDBLookupComboBox is a data-aware combo-box for examining a lookup table in a database.

TCustomComboBox

The base class for combo-box components.

How To Use Data-aware Controls

HowToUseDataAwareControls - Hints for accessing databases.