TDBImage

type TDBImage = class(TCustomImage)

protected

  procedure Notification(); override;

Handles notifications when a component in the class instance is added or removed.

  procedure DataChange();

Performs actions needed when the content in the linked dataset has been changed.

  procedure UpdateData(); virtual;

Performs actions needed to validate and store the content for the image control.

  procedure PictureChanged(); override;

Performs actions needed when the Picture property in the image control has been changed.

  class procedure WSRegisterClass; override;

Register the component class with the widgetset.

  procedure DoCopyToClipboard;

Implements the clipboard Copy (Ctrl+C) command.

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.

  property Field: TField; [r]

Definition for the field in the linked dataset where the control value is stored.

  procedure Change; virtual;

Notifies the linked dataset when the value in the control is changed.

  procedure LoadPicture; virtual;

Loads the graphic content for the control from a field in the linked dataset.

  procedure CopyToClipboard;

Performs actions needed for the Clipboard Copy (Ctrl+C) command.

  procedure CutToClipboard;

Performs actions needed for the Clipboard Cut (Ctrl+C) command.

  procedure PasteFromClipboard;

Performs actions needed for the Clipboard Paste (Ctrl+V) command.

  property PictureLoaded: Boolean; [r]

Indicates if the graphic content for the data-aware control has been loaded from its linked dataset.

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 AntialiasingMode: TAntialiasingMode;

Indicates if anti-aliasing is used when rendering the image.

  property AutoDisplay: Boolean; [rw]

AutoDisplay - if True, automatically displays when focus is given.

  property AutoSize: Boolean;

Allows automatic adjustment of the size for the control, according to its content.

  property BorderSpacing: TControlBorderSpacing;

Determines the inner and outer border spacing for this control.

  property Center: Boolean;

Indicates if the image should be centered.

  property Constraints: TSizeConstraints;

Contains the minimum and maximum Width and Height for the control.

  property DataField: string; [rw]

Contains the name of the field with the value for the control.

  property DataSource: TDataSource; [rw]

Provides access to the dataset with content for the control.

  property DragCursor: TCursor;

The cursor shape shown during a drag operation.

  property DragKind: TDragKind;

Indicates the action performed for a drag operation: drag-and-drop or drag-and-dock.

  property DragMode: TDragMode;

Determines how a drag operation is started for the control.

  property KeepOriginXWhenClipped: Boolean;

Preserves the Left coordinate when a clipped image is centered.

  property KeepOriginYWhenClipped: Boolean;

Preserves the Top coordinate when a clipped image is centered.

  property OnClick: TNotifyEvent;

Notification handler for mouse clicks.

  property OnContextPopup: TContextPopupEvent;

Invoked when a context-sensitive pop-up menu is requested.

  property OnDblClick: TNotifyEvent;

Event handler signalled when a mouse double click occurs in the control.

  property OnDBImageRead: TOnDBImageRead; [rw]

Event to read a custom header from image stream.

  property OnDBImageWrite: TOnDBImageWrite; [rw]

Event to write a custom header into image stream.

  property PopupMenu: TPopupMenu;

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

  property OnDragDrop: TDragDropEvent;

Event handler signalled when an object is dropped onto the control.

  property OnDragOver: TDragOverEvent;

Event handler signalled when a control is dragged over the control instance.

  property OnEndDrag: TEndDragEvent;

Event handler signalled for the end of a drag-drop operation.

  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 signalled when the mouse pointer is moved in 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 signalled for a downward movement of the mouse wheel.

  property OnMouseWheelUp: TMouseWheelUpDownEvent;

Event handler signalled for an upward movement of the mouse wheel.

  property OnResize: TNotifyEvent;

Notification handler for a resize of the control.

  property OnStartDrag: TStartDragEvent;

Event handler signalled for the start of a dragging operation.

  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 Proportional: Boolean;

True if image is proportional.

  property QuickDraw: Boolean; [rw]

QuickDraw - if True, quick drawing is implemented.

  property ReadOnly: Boolean; [rw]

Indicates if the control cannot modify the image in the field for the linked dataset.

  property ShowHint: Boolean;

Enables Hint display for the control.

  property Stretch: Boolean;

Indicates if the image is resized to the client area for the control.

  property StretchInEnabled: Boolean;

Allows the image to be resized proportionally when the image drawing area is shrunk.

  property StretchOutEnabled: Boolean;

Allows the image to be resized proportionally when the image drawing area is expanded.

  property Transparent: Boolean;

Indicates if the image has a clear, non-opaque background.

  property Visible: Boolean;

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

  property WriteHeader: Boolean; [rw]

Write a header in the image stream.

end;

TDBImage

TDBImage - a data-aware Image box to display a single image from a dataset.

TCustomImage

Implements the base class for TImage.

TGraphicControl

TGraphicControl is the base class for all lightweight 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

How To Use Data-aware Controls

HowToUseDataAwareControls - Hints for accessing databases.