UXML element Scroller

A Scroller lets users scroll through content in your user interface.

Create a Scroller

You can create a Scroller with UI Builder, UXML, or C#. The following C# example creates a Scroller with a default value, low limit, and high limit, and sets the direction of the Scroller:

var scroller = new Scroller();
scroller.value = 42;
scroller.lowValue = 0;
scroller.highValue = 100;
scroller.direction = SliderDirection.Vertical;

示例

The following UXML example creates a Scroller:

[!code-xml[(External/Resources/editor_resources/Assets/Editor Default Resources/UIPackageResources/Snippets/UXML/ScrollerSnippet.uxml)]

The following C# example illustrates some of the customizable functionalities of the Scroller:

[!code-cs[(Modules/UIElementsSamplesEditor/Snippets/ScrollerSnippet.cs#sample)]

To try this example live in Unity, go to Window > UI Toolkit > Samples.

C# base class and namespace

C# class: Scroller
Namespace: UnityEngine.UIElements
Base class: VisualElement

Member UXML attributes

This element has the following member attributes:

名称	类型	描述
direction	UIElements.SliderDirection	Direction of this scrollbar.
high-value	float	Maximum value.
low-value	float	Minimum value.
value	float	Value that defines the slider position. It lies between lowValue and highValue.

Inherited UXML attributes

This element inherits the following attributes from its base class:

名称	类型	描述
focusable	boolean	True if the element can be focused.
tabindex	int	An integer used to sort focusables in the focus ring. Must be greater than or equal to zero.

This element also inherits the following attributes from VisualElement:

名称	类型	描述
content-container	string	Child elements are added to it, usually this is the same as the element itself.
data-source	Object	Assigns a data source to this VisualElement which overrides any inherited data source. This data source is inherited by all children.
data-source-path	string	Path from the data source to the value.
name	string	The name of this VisualElement. Use this property to write USS selectors that target a specific element. The standard practice is to give an element a unique name.
picking-mode	UIElements.PickingMode	Determines if this element can be pick during mouseEvents or IPanel.Pick queries.
style	string	Reference to the style object of this element. Contains data computed from USS files or inline styles written to this object in C#.
tooltip	string	Text to display inside an information box after the user hovers the element for a small amount of time. This is only supported in the Editor UI.
usage-hints	UIElements.UsageHints	A combination of hint values that specify high-level intended usage patterns for the VisualElement. This property can only be set when the VisualElement is not yet part of a Panel. Once part of a Panel, this property becomes effectively read-only, and attempts to change it will throw an exception. The specification of proper UsageHints drives the system to make better decisions on how to process or accelerate certain operations based on the anticipated usage pattern. Note that those hints do not affect behavioral or visual results, but only affect the overall performance of the panel and the elements within. It’s advised to always consider specifying the proper UsageHints, but keep in mind that some UsageHints might be internally ignored under certain conditions (e.g. due to hardware limitations on the target platform).
view-data-key	string	Used for view data persistence, such as tree expanded states, scroll position, or zoom level. This key is used to save and load the view data from the view data store. If you don’t set this key, the persistence is disabled for the associated VisualElement. For more information, refer to View data persistence.

USS classes

The following table lists all the C# public property names and their related USS selector.

C# property	USS selector	描述
ussClassName	.unity-scroller	USS class name of elements of this type.
horizontalVariantUssClassName	.unity-scroller--horizontal	USS class name of elements of this type, when they are displayed horizontally.
verticalVariantUssClassName	.unity-scroller--vertical	USS class name of elements of this type, when they are displayed vertically.
sliderUssClassName	.unity-scroller__slider	USS class name of slider elements in elements of this type.
lowButtonUssClassName	.unity-scroller__low-button	USS class name of low buttons in elements of this type.
highButtonUssClassName	.unity-scroller__high-button	USS class name of high buttons in elements of this type.
disabledUssClassName	.unity-disabled	USS class name of local disabled elements.

You can also use the Matching Selectors section in the Inspector or the UI Toolkit Debugger to see which USS selectors affect the components of the VisualElement at every level of its hierarchy.

其他资源

• ScrollView