TDBEdit class

In unit DBCtrls

TDBEdit - a data-aware edit box for processing a single text-string from a dataset.

Declaration

pascal

TDBEdit = class(TCustomMaskEdit)

Inheritance

Description

TDBEdit is a TCustomMaskEdit descendant which implements a data-aware control which allows editing of the value in a database field. Like its ancestor class, TDBEdit displays and edits a single line of text. For multi-line text values, use the TDBMemo control.

TDBEdit extends the ancestor class with additional properties needed to configure the data-aware features in the control, including:

DataSource: Component which provides access to the dataset with the field value
DataField: Name of the field in the dataset edited in the control
Field: Field definition and metadata in the dataset
ReadOnly: Indicates if the value for the control (and its field) cannot be changed

An internal TFieldDataLink class instance is used to maintain an association between the control and its data source. TDBEdit provides methods which support use of TBasicAction with the data link for the control.

TDBEdit extends the masking capabilities from the ancestor to include use of mask-related properties like EditMask and Alignment set in the TField instance for the control. Use the CustomEditMask property to enable an edit mask independent of the value defined in the dataset Field.

Properties

`Field`	public	Provides access to the field definition for the data-aware control.
`CustomEditMask`	published	Indicates if a custom edit mask is used in the control.
`DataField`	published	Contains the name of the field with the value for the control.
`DataSource`	published	Provides access to the dataset with content for the control.
`ReadOnly`	published	Indicates if the control cannot modify the field in the linked dataset.
`Align`	published	Specifies the placement of the control on its Parent control.
`Alignment`	published	The horizontal alignment for the text in the control (left, right, or centered).
`Anchors`	published	The set of anchor definitions for this control.
`AutoSelect`	published	Enables auto-selection of text when focused.
`AutoSize`	published	Allows automatic adjustment of the size for the control, according to its content.
`BiDiMode`	published	Indicates whether text controls use in bi-directional reading.
`BorderSpacing`	published	Determines the inner and outer border spacing for this control.
`BorderStyle`	published	Indicates the border style displayed around the control.
`CharCase`	published	Controls the character case applied to values entered in the control.
`Color`	published	The background color for the control.
`Constraints`	published	Contains the minimum and maximum Width and Height for the control.
`DoubleBuffered`	published	When enabled, it reduces flicker when the control is painted.
`DragCursor`	published	The cursor shape shown during a drag operation.
`DragKind`	published	Indicates the action performed for a drag operation: drag-and-drop or drag-and-dock.
`DragMode`	published	Determines how a drag operation is started for the control.
`Enabled`	published	Determines whether the control responds to mouse or keyboard input.
`EditMask`	published	Contains the mask characters classes and literals used to format/obscure the value for the control.
`Font`	published	The font to be used for text display in this control.
`MaxLength`	published	The maximum length of the value entered in Text, or 0 (zero) for unlimited length.
`ParentBiDiMode`	published	Indicates whether the BiDiMode settings in the Parent control are used.
`ParentColor`	published	Use the Color from the Parent control, when enabled.
`ParentDoubleBuffered`	published	Value for the DoubleBuffered property in a Parent control.
`ParentFont`	published	Indicates if the Font from the Parent control is used in the control.
`ParentShowHint`	published	If True, the value of ShowHint for the control will be the same as the one from the Parent. Default is True.
`PasswordChar`	published	Allows obfuscation of the displayed text, showing all characters as PasswordChar.
`PopupMenu`	published	A context-sensitive menu that pops up when the right mouse button is clicked over this control.
`ShowHint`	published	Enables Hint display for the control.
`TabOrder`	published	Indicates the navigation order for the control when the user presses the Tab or Shift+Tab key.
`TabStop`	published	Allows the user to navigate to / from the control by pressing the Tab or Shift+Tab keys.
`TextHint`	published	Default hint text shown when the Text property is empty for the control.
`Visible`	published	Allows the control, and all of its children, to be displayed or hidden.

Methods

`GetReadOnly`	protected	Gets the value for the ReadOnly property.
`SetReadOnly`	protected	Sets the value for the ReadOnly property.
`KeyDown`	protected	Handles key down events in the control.
`UTF8KeyPress`	protected	Handles UTF-8 characters for the data-aware control.
`Notification`	protected	Handles notifications when a component is added or removed from the control.
`EditCanModify`	protected	Indicates if the control can modify the text for the control value.
`GetEditText`	protected	Gets the value for the EditText property.
`Change`	protected	Performs actions needed when the value for the control has been changed.
`Reset`	protected	Cancels pending changes to the linked dataset.
`WMSetFocus`	protected	Ensures that the control has the input focus.
`WMKillFocus`	protected	Ensures that the liked dataset is updated when the modified control loses input focus.
`WndProc`	protected	Handles the specified LCL message for the control.
`Create`	public	Constructor for the class instance.
`Destroy`	public	Destructor for the class instance.
`ExecuteAction`	public	Provides support for TBasicAction in the control.
`UpdateAction`	public	Updates the specified action to reflect the current state in the linked dataset.

Events

`OnChange`	published	Event handler signalled when the text for the control is changed.
`OnClick`	published	Notification handler for mouse clicks.
`OnContextPopup`	published	Invoked when a context-sensitive pop-up menu is requested.
`OnDblClick`	published	Event handler signalled when a mouse double click occurs in the control.
`OnDragDrop`	published	Event handler signalled when an object is dropped onto the control.
`OnDragOver`	published	Event handler signalled when a control is dragged over the control instance.
`OnEditingDone`	published	Event handler signalled when editing is completed for the control.
`OnEndDrag`	published	Event handler signalled for the end of a drag-drop operation.
`OnEnter`	published	Event handler signalled when the control receives focus.
`OnExit`	published	Event handler signalled when the control loses focus.
`OnKeyDown`	published	Event handler signalled when a key is down while control has focus.
`OnKeyPress`	published	Event handler signalled when a key is being pressed while the control has focus.
`OnKeyUp`	published	Event handler signalled when a key becomes up (not pressed) while the control has focus.
`OnMouseDown`	published	Event handler signalled when a mouse down event is handled for the control.
`OnMouseEnter`	published	Event handler signalled when the mouse pointer has entered the control.
`OnMouseLeave`	published	Event handler signalled when the mouse pointer has left the control.
`OnMouseMove`	published	Event handler signalled when the mouse pointer is moved in the control.
`OnMouseUp`	published	Event handler signalled when a mouse up event is handled for the control.
`OnMouseWheel`	published	Event handler for mouse wheel turned.
`OnMouseWheelDown`	published	Event handler signalled for a downward movement of the mouse wheel.
`OnMouseWheelUp`	published	Event handler signalled for an upward movement of the mouse wheel.
`OnStartDrag`	published	Event handler signalled for the start of a dragging operation.
`OnUTF8KeyPress`	published	Handler for a character entered by the user.