TrackBar

Inheritance Hierarchy

Description

The TrackBar component is a control in the form of a slider.

Working with the Component

Slider position can be changed using the mouse cursor or the keyboard. The current value is tracked in the OnChange event. To manage slider position, use the Position property. Value of the TickMarks property determines the scale position relative to the component. The Orientation property determines slider orientation. Value of the TickStyle property determines a scale representation method.

The LineSize and PageSize properties determine the slider offset when the user moves the slider by the UP and DOWN keys or the PAGE UP and the PAGE DOWN keys.

Set the values to the SelStart and SelEnd properties and visually highlight the scale range, which can be a recommended value range. At the same time, nothing prevents the user from moving the slider beyond this range.

Example

Properties of the TrackBar Component

	Property name	Brief description
	Align	The Align property determines behavior of the component when its parent component is resized.
	AllowDrag	The AllowDrag property determines whether an object can be dragged from the component.
	AllowDrop	The AllowDrop property determines whether the component can accept a dragged object.
	Anchors	The Anchors property returns settings that determine the percentage of the size change for the current component when the parent component is resized.
	BorderStyle	The BorderStyle property determines a component border style.
	Brush	The Brush property determines the brush that is used to fill component area.
	ClientHeight	The ClientHeight property is used to receive or specify the height of the component’s client area.
	ClientWidth	The ClientWidth property is used to receive or specify the width of the component’s client area.
	Color	The Color property determines a component background color.
	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 is used to store any custom data.
	Enabled	The Enabled property determines whether the component is available for the 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 that is used to display text.
	Frequency	The Frequency property determines the value used on calculating the number of intervals and location of component area's ticks.
	Height	The Height property determines component height.
	HelpContext	The HelpContext property determines a unique index for the context help section for this component.
	Hint	The Hint property determines a component tooltip text.
	Left	The Left property determines the coordinate of the left border of the component.
	LineSize	The LineSize property determines how much the slider is shifted on clicking arrow buttons.
	Max	The Max property determines the maximum value of the change range.
	Min	The Min property determines the minimum value of the change range.
	Name	The Name property determines a component name.
	Orientation	The Orientation property determines component orientation on the form.
	PageSize	The PageSize property determines how much the slider is shifted on pressing PAGE UP and PAGE DOWN buttons, or on clicking the edge of the scale.
	Parent	The Parent property determines a parent component.
	ParentColor	The ParentColor property determines whether the component inherits the color of the parent component.
	ParentFont	The ParentFont property determines whether the component uses the font of the parent component.
	ParentShowHint	The ParentShowHint property determines whether a tooltip is displayed.
	PopupMenu	The PopupMenu property determines the context menu opened by clicking the component with the additional mouse button.
	Position	The Position property determines the current slider position.
	Scrolls	The Scrolls property returns parameters of component's scrollbars.
	SelEnd	The SelEnd property determines the end selection position.
	SelStart	The SelStart property determines the start selection position.
	ShowHint	The ShowHint property enables and disables showing a component tooltip.
	SliderVisible	The SliderVisible property determines whether the component slider is visible.
	TabOrder	The TabOrder property determines the component position in the tab order.
	TabStop	The TabStop property determines whether the component is focused when the TAB key 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 he wishes.
	Text	The Text property determines the row identifying a component for the user.
	ThumbLength	The ThumbLength property determines slider length.
	TickMarks	The TickMarks property determines how tick marks are set.
	TickStyle	The TickStyle property determines a style of setting tick marks.
	Top	The Top property determines the coordinate of the top border of the component.
	Visible	The Visible property determines visibility of the component during execution.
	Width	The Width property determines component width.

Methods of the TrackBar 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 into screen coordinates.
	DoDragDrop	The DoDragDrop method enables the user to start dragging 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 into 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.
	SetTick	The SetTick method sets a tick mark in the specified position.

Events of the TrackBar Component

	Event name	Brief description
	OnBeginDrag	The OnBeginDrag event occurs for a component when the user starts to drag an object from the component.
	OnChange	The OnChange event occurs when the slider position changes.
	OnClick	The OnClick event occurs if the user clicks the component area.
	OnDblClick	The OnDblClick event occurs if the user double-clicks the component area.
	OnDragDrop	The OnDragDrop event occurs for the component if the 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 the component when the user drags an object over it.
	OnEnter	The OnEnter event occurs when the component receives focus.
	OnExit	The OnExit event occurs when the component loses focus.
	OnHScroll	The OnHScroll event occurs when horizontal scrollbar slider changes its position.
	OnKeyDown	The OnKeyDown event occurs if the component is focused and a keyboard key is pressed.
	OnKeyPress	The OnKeyPress event occurs if the component is focused when the user presses a character key.
	OnKeyPreview	The OnKeyPreview event occurs prior to each event related to key pressing.
	OnKeyUp	The OnKeyUp event occurs if the component is focused and the user releases any button previously pressed.
	OnMouseDown	The OnMouseDown event occurs if the pointer is in component's area and a mouse key 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 the component is focused when the mouse wheel is rotated.
	OnVScroll	The OnVScroll event occurs when vertical scrollbar slider changes its position.