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

TDBCheckBox

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

TDBCheckBox - a data-aware checkbox for use with logical fields in a database

Declaration

Source position: dbctrls.pp line 595

type TDBCheckBox = class(TCustomCheckBox) end;

protected

  function GetFieldCheckState; virtual;

  

GetFieldCheckState - returns the checkbox state for the current field

  procedure DataChange();

  

DataChange - uses GetFieldCheckState to update the State

  procedure DoOnChange; override;

  procedure UpdateData();

  

UpdateData - examines the State to see whether it has changed

  procedure Notification(); override;

  

public

  constructor Create(); override;

  

Create - constructor for TDBCheckBox: calls inherited Create, forms logical connections for checked and unchecked, sets initial style and state, forms datalinks and actions

  destructor Destroy; override;

  

Destroy - destructor for TDBCheckBox: frees links and calls inherited Destroy

  function ExecuteAction(); override;

  function UpdateAction(); override;

  property Checked: Boolean;

  

The state of the check mark. Here always False, can be implemented in derived classes.

  property Field: TField; [r]

  

The Field in the DataSet with which the box is to be associated

  property State: TCheckBoxState;

  

Indicates whether the check box is checked (selected), unchecked (deselected) or grayed (disabled).

published

  property AllowGrayed: Boolean;

  

Allows the check box to be in a "grayed" state.

  property Align: TAlign;

  property Anchors: TAnchors;

  

The set of anchor definitions for this control.

  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 Caption: TCaption;

  

The text describing the control to the user.

  property Color: TColor;

  

The background color of the control.

  property DataField: string; [rw]

  

The name (as a string) of the field with which the checkbox is to be associated

  property DataSource: TDataSource; [rw]

  

The DataSource containing the Field that is to be associated with this checkbox

  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 Enabled: Boolean;

  

Determines whether the control reacts on mouse or keyboard input.

  property Font: TFont;

  property Hint: TTranslateString;

  

The text to show in the Hint window for this control.

  property OnChange: TNotifyEvent;

  

Handler for any change in properties of the control.

  property OnClick: TNotifyEvent;

  

Notification handler for 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 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 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 OnStartDrag: TStartDragEvent;

  

Event handler for the start of a dragging operation.

  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 PopupMenu: TPopupMenu;

  

A context-sensitive menu that pops up when the right mouse button is clicked over this control

  property ReadOnly: Boolean; [rw]

  

ReadOnly - if True, data may be read but not written or modified (doesn't make much sense for a check-box unless the box is NOT Enabled!)

  property ShowHint: Boolean;

  

Enables the Hint display.

  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 ValueChecked: string; [rw]

  

ValueChecked - the value to use when the box is checked, for example True or 1

  property ValueUnchecked: string; [rw]

  

ValueUnchecked - the value to use when the box is unchecked, for example False or 0

  property Visible: Boolean;

  

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

Inheritance

TDBCheckBox

  

TDBCheckBox - a data-aware checkbox for use with logical fields in a database

|

TCustomCheckBox

  

The base class for checkbox components.

|

TButtonControl

  

The base class for various button controls.

|

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

See also

HowToUseDataAwareControls

  

HowToUseDataAwareControls - Hints for accessing databases

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