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

TDBMemo

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

TDBMemo - a data-aware Memo box to process the multi-line text of a single field in a dataset

Declaration

Source position: dbctrls.pp line 882

type TDBMemo = class(TCustomMemo) end;

protected

  function GetReadOnly; override;

  procedure SetReadOnly(); override;

  procedure DataChange();

  

DataChange - if Data changed, loads the new data into the appropriate part of the Field

  procedure Notification(); override;

  

  procedure UpdateData();

  

UpdateData - if data changed, copy new text via the datalink

  procedure Change; override;

  procedure KeyDown(); override;

  procedure KeyPress(); override;

  

Invokes the OnKeyPress handler.

  procedure WndProc(); override;

  

The general message handler for this control.

  class procedure WSRegisterClass; override;

public

  constructor Create(); override;

  

Create - constructor for TDBMemo: calls inherited Create, then sets style and forms datalinks and actions

  destructor Destroy; override;

  

Destroy - destructor for TDBMemo: frees datalinks then calls inherited Destroy

  procedure EditingDone; override;

  

EditingDone - if link allows modifications and is in an Editing state, updates data via the link then calls inherited EditingDone

  procedure LoadMemo; virtual;

  

LoadMemo - tries to load data from current field as a string if possible, otherwise returns an exception

  function ExecuteAction(); override;

  function UpdateAction(); override;

  property Field: TField; [r]

  

The field in the DataSet to which this control is to be linked. Can be referred to by name, or as an index

published

  property Align: TAlign;

  

Specifies the placement of the control inside its Parent.

  property Anchors: TAnchors;

  

The set of anchor definitions for this control.

  property AutoDisplay: Boolean; [rw]

  

AutoDisplay - if True, automatically displays the data when loaded

  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 Constraints: TSizeConstraints;

  property DataField: string; [rw]

  

The name of the field, as a string (ie cannot be referred to as an Index)

  property DataSource: TDataSource; [rw]

  

The DataSource from which information is obtained to display in this control. Usually the result of a database query

  property DragCursor: TCursor;

  

The cursor shape shown while the control is dragged.

  property DragMode: TDragMode;

  

Allows the user to drag the control.

  property Enabled: Boolean;

  property Font: TFont;

  

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

  property MaxLength: Integer;

  

The maximum length of the text; zero for unlimited.

  property OnChange: TNotifyEvent;

  

Event handler for any change in text.

  property OnClick: TNotifyEvent;

  property OnContextPopup: TContextPopupEvent;

  property OnDblClick: TNotifyEvent;

  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 OnEditingDone: TNotifyEvent;

  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;

  property OnMouseEnter: TNotifyEvent;

  property OnMouseLeave: TNotifyEvent;

  property OnMouseMove: TMouseMoveEvent;

  property OnMouseUp: TMouseEvent;

  property OnMouseWheel: TMouseWheelEvent;

  property OnMouseWheelDown: TMouseWheelUpDownEvent;

  property OnMouseWheelUp: TMouseWheelUpDownEvent;

  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 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;

  property PopupMenu: TPopupMenu;

  

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

  property ReadOnly: Boolean; [rw]

  

Prevents the user from changing the text.

  property ScrollBars: TScrollStyle;

  

Adds vertical and/or horizontal scrollbars to the control.

  property ShowHint: Boolean;

  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.

  property WordWrap: Boolean;

  

Allows long logical lines (paragraphs) to wrap into multiple display lines.

Inheritance

TDBMemo

  

TDBMemo - a data-aware Memo box to process the multi-line text of a single field in a dataset

|

TCustomMemo

  

The base class for multi-line text controls.

|

TCustomEdit

  

The base class for controls presenting editable text.

|

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.