Button

Inheritance Hierarchy

          IComponent

          IControl

          IButton

          Button

Description

The Button component realizes a standard Windows button.

In general the Button component is used to initiate some events.

In the button text (the Text property) you can realize using hotkeys; to do so select one of the text characters by inserting an ampersand "&" before it. This character is not displayed in the button text, and the next character is underlined. As a result, a user can press ALT + the key of the selected character instead of clicking the button.

The main event of a button is OnClick, which occurs when a user clicks this button. In the handler of this event you can include a set of operators, which must be executed when a user clicks the button. The ImageButton component grants wider options for setting appearance.

Example

Properties of the Button Component

  Property name Brief description
Align The Align property determines component's behavior on resizing its parent component.
AllowDrag The AllowDrag property determines whether an object can be dragged from a component.
AllowDrop The AllowDrop property determines whether a component can accept a dragged object.
Anchors The Anchors property returns settings determining % of the size change for the current component when the parent component is resized.
Brush The Brush property specifies the brush used to fill the component area.
CancelButton The CancelButton property determines whether the  OnClick  event is handled on clicking the ESC button.
ClientHeight The ClientHeight property receives or specifies the height of the component’s client space.
ClientWidth The ClientWidth property receives or specifies the width of the component’s client space.
Color The Color property determines the background color of a component.
ComponentCount The ComponentCount property returns the number of child components.
Components The Components property returns the child component.
Cursor The Cursor property determines the look of the cursor over the component.
Data The Data property stores any user data.
DefaultButton The DefaultButton property determines that pressing the ENTER key is equivalent to clicking this button.
Enabled The Enabled property determines whether a component is available for a user.
Focused The Focused property returns True if the focus is set on the component.
Font The Font property determines the set of characteristics, describing the font, used to display text.
Height The Height property determines the component height.
HelpContext The HelpContext property determines the unique index for a section of a context help for this component.
Hint The Hint property determines the hint text for the component.
Left The Left property determines the coordinate of the left border of the component.
ModalResult The ModalResult property determines the result returned after clicking the button on the modal form on closing this form.
Name The Name property specifies the component name.
Parent The Parent property determines the parent component.
ParentColor The ParentColor property determines whether a component inherits the color of the parent component.
ParentFont The ParentFont property determines whether a component should use the font of the parent component.
ParentShowHint The ParentShowHint property determines when a tooltip is displayed.
PopupMenu The PopupMenu property determines context menu which opens on right-clicking the component.
Scrolls The Scrolls property returns parameters of component's scrollbars.
ShowHint The ShowHint property enables and disables showing a hint for the component.
TabOrder The TabOrder property determines the component position in the tab order.
TabStop The TabStop property determines whether the component gets focused when the TAB button is pressed.
Tag The Tag property is not used by the compiler. The user can change the value of the Tag property and use it as required.
Text The Text property determines the row identifying a component for a user.
Top The Top property determines the coordinate of the top border of the component.
Visible The Visible property determines the visibility of the component during execution.
Width The Width property determines the component width.

Methods of the Button Component

  Method name Brief description
BringToFront The BringToFront method brings a component to front.
ClientToScreen The ClientToScreen method converts the coordinates of a point specified relative to the component coordinate system to screen coordinates.
DoDragDrop The DoDragDrop method starts drag-and-drop operation.
GetImage The GetImage method returns the image of the component with all the child components.
ScreenToClient The ScreenToClient method converts screen coordinates of a point to coordinates specified relative to the component coordinate system.
SendToBack The SendToBack method sends a component to back.
SetFocus The SetFocus method sets focus to this component.

Events of the Button Component

  Event name Brief description
OnBeginDrag The OnBeginDrag event occurs for a component, when a user starts to drag an object from the component.
OnClick The OnClick event occurs if the user clicks component area using the main mouse button.
OnDblClick The OnDblClick event occurs if the user double-clicks the component area.
OnDragDrop The OnDragDrop event occurs for a component if a user drops a dragged object over it.
OnDragEnter The OnDragEnter event occurs when a dragged object crosses the borders of this component.
OnDragLeave The OnDragLeave event occurs when a dragged object leaves the borders of this component.
OnDragOver The OnDragOver event occurs for this component when a user drags a dragged object over it.
OnEnter The OnEnter event occurs when a component receives focus.
OnExit The OnExit event occurs when a component loses focus.
OnHScroll The OnHScroll event occurs when horizontal scrollbar slider changes its position.
OnKeyDown The OnKeyDown event occurs if a component is focused and a keyboard key is pressed.
OnKeyPress The OnKeyPress event occurs if a component is focused when a user presses a character key.
OnKeyPreview The OnKeyPreview event occurs prior to each event requiring clicking.
OnKeyUp The OnKeyUp event occurs if a component is focused and a user releases any button previously pressed.
OnMouseDown The OnMouseDown event occurs when the pointer is in component area and a mouse button is pressed.
OnMouseEnter The OnMouseEnter event occurs when mouse cursor enters the component area.
OnMouseHover The OnMouseHover event occurs when mouse cursor is held in the component area.
OnMouseLeave The OnMouseLeave event occurs when mouse cursor leaves the component area.
OnMouseMove The OnMouseMove event occurs on moving the cursor over component.
OnMouseUp The OnMouseUp event occurs on releasing mouse button when the cursor is in component area.
OnMouseWheel The OnMouseWheel event occurs if a component is focused when a user rotates a mouse wheel.
OnVScroll The OnVScroll event occurs when position of vertical scrollbar slider is changed.

See also:

Standard Components