[Overview][Constants][Types][Classes][Procedures and functions][Index] Reference for unit 'StdCtrls' (#lcl)

TComboBox

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

A combination of an edit box and a (drop-down) list allowing one of several options to be chosen.

Declaration

Source position: stdctrls.pp line 450

type TComboBox = class(TCustomComboBox)

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;

  

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

  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;

  

Indicates whether text controls use in bi-directional reading.

  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: TColor;

  

The background color of the control.

  property Constraints: TSizeConstraints;

  

Contains the minimum and maximum Width and Height 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 responds to 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 ItemIndex: Integer;

  

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

  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 for 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 OnEndDrag: TEndDragEvent;

  

Notification handler for the end of a drag operation.

  property OnDropDown: TNotifyEvent;

  

Handler invoked when the list has dropped down.

  property OnEditingDone: TNotifyEvent;

  

Event handler signalled when editing is done.

  property OnEnter: TNotifyEvent;

  

Handler for control receiving the focus.

  property OnExit: TNotifyEvent;

  

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

  property OnGetItems: TNotifyEvent;

  

Handler invoked when widgetset items list can be populated.

  property OnKeyDown: TKeyEvent;

  

Handler for keyboard key pressed.

  property OnKeyPress: TKeyPressEvent;

  

Handler for a character entered by the user.

  property OnKeyUp: TKeyEvent;

  

Event handler signalled when a key up event has occurred for the control.

  property OnMeasureItem: TMeasureItemEvent;

  

Handler invoked when the height for an item is needed.

  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;

  

Uses 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;

  

Disallows free-form entry of Text into the combo-box edit field.

  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;

  

Enables or disables keyboard navigation using the Tab or Shift+Tab keys.

  property Text: TCaption;

  

The value in the edit box for the control.

  property TextHint: TTranslateString;

  

Default hint text shown when the Text property is empty and the control is not focused.

  property Visible: Boolean;

  

Allows the control, and all of its children, to be displayed or hidden.

end;

Inheritance

TComboBox

  

A combination of an edit box and a (drop-down) list allowing one of several options to be chosen.

|

TCustomComboBox

  

The base class for combo-box components.

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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

?

TObject

Description

The Text property reflects the text entered into the edit box, or selected from the list.

The selectable values are kept in the Items list. Clicking on the ellipsis character (...), next to Items in the Object Inspector, opens an editor which allows the designer to populate the Items list.

At run-time, the entry selected from the list replaces the text in the edit box, and ItemIndex holds the (zero-based) index number of the selected item.

If no value is selected from the drop-down list, the default text (if any) remains, or any information typed directly into Text will be returned, and ItemIndex takes the value of -1.

See also

HowToUseStdCtrls

  

How to use StdCtrls, ComCtrls or ExtCtrls.

TComboBox.Items

  

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

TComboBox.ItemIndex

  

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