A ListView is a vertically scrollable area that links to and displays a list of items.
Note: The horizontal and vertical Scroller elements are standard UI Toolkit Scrollers.
If you want to create a ListView with complex data and bind the ListView to visual elements, do the following:
makeItem and bindItem to bind the ListView to data, register the appropriate callbacks, and modify the linked data source as needed.unbindItem to recycle an element for the ListView and unbind the data.destroyItem to clear the registered callbacks.You can use a ScrollView control to create the same functionalities as using a ListView. However, a ListView is more efficient than a ScrollView when you do the following:
To change how item height is used to drive content, use the VirtualizationMethod:
VirtualizationMethod.FixedHeight sets all items to the same height.VirtualizationMethod.DynamicHeight allows items to have varying heights.To control the scroll speed of the ListView, override the USS built-in variable --unity-metrics-single_line-height. The default value is 18px. For example:
:root {
--unity-metrics-single_line-height: 500px;
}
Important: When you use CloneTree() without parameter or Instantiate(), it adds a TemplateContainer that stops the line height from propagating. Use CloneTree(root) instead.
The best way to learn how to use ListView is to try examples:
GameSwitch objects.C# class: ListView
Namespace: UnityEngine.UIElements
Base class: BaseListView
This element inherits the following attributes from its base class:
| 名称 | 类型 | 描述 |
|---|---|---|
binding-path |
string |
Path of the target property to be bound. |
fixed-item-height |
int |
The height of a single item in the list, in pixels. This property must be set when using the virtualizationMethod is set to FixedHeight, for the collection view to function. If set when virtualizationMethod is DynamicHeight, it serves as the default height to help calculate the number of items necessary and the scrollable area, before items are laid out. It should be set to the minimum expected height of an item. |
focusable |
boolean |
True if the element can be focused. |
header-title |
string |
This property controls the text of the foldout header when using showFoldoutHeader. |
reorder-mode |
UIElements.ListViewReorderMode |
This property controls the drag and drop mode for the list view. The default value is Simple. When this property is set to Animated, Unity adds drag handles in front of every item and the drag and drop manipulation pushes items with an animation when the reordering happens. Multiple item reordering is only supported with the Simple drag mode. |
reorderable |
boolean |
Gets or sets a value that indicates whether the user can drag list items to reorder them. The default value is false which allows the user to drag items to and from other views when you implement canStartDrag, setupDragAndDrop, dragAndDropUpdate, and handleDrop. Set this value to true to allow the user to reorder items in the list. |
selection-type |
UIElements.SelectionType |
Controls the selection type. The default value is SelectionType.Single. When you set the collection view to disable selections, any current selection is cleared. |
show-add-remove-footer |
boolean |
This property controls whether a footer will be added to the list view. The default value is false. When this property is set to true, Unity adds a footer under the scroll view. This footer contains two buttons: A “+” button. When clicked, it adds a single item at the end of the list view. A “-” button. When clicked, it removes all selected items, or the last item if none are selected. |
show-alternating-row-backgrounds |
UIElements.AlternatingRowBackground |
This property controls whether the background colors of collection view rows alternate. Takes a value from the AlternatingRowBackground enum. |
show-border |
boolean |
Enable this property to display a border around the collection view. If set to true, a border appears around the ScrollView that the collection view uses internally. |
show-bound-collection-size |
boolean |
This property controls whether the list view displays the collection size (number of items). The default value is true. When this property is set to true, Unity displays the collection size as the first item in the list, but does not make it an actual list item that is part of the list index. If you query for list index 0, Unity returns the first real list item, and not the collection size. If showFoldoutHeader is set to true, the collection size field is included in the header instead. You can use this property to debug a ListView because the property indicates whether the data source is linked correctly. In production, the collection size rarely displays as a line item in a ListView.SA: UnityEditor.UIElements.BindingExtensions.Bind
|
show-foldout-header |
boolean |
This property controls whether the list view displays a header, in the form of a foldout that can be expanded or collapsed. The default value is false. When this property is set to true, Unity adds a foldout in the hierarchy of the list view and moves the scroll view inside that newly created foldout. You can change the text of this foldout with headerTitle property on the ListView. If showBoundCollectionSize is set to true, the header includes a TextField to control the array size, instead of using the field as part of the list. |
tabindex |
int |
An integer used to sort focusables in the focus ring. Must be greater than or equal to zero. |
virtualization-method |
UIElements.CollectionVirtualizationMethod |
The virtualization method to use for this collection when a scroll bar is visible. Takes a value from the CollectionVirtualizationMethod enum.The default value is FixedHeight. When using fixed height, specify the fixedItemHeight property. Fixed height is more performant but offers less flexibility on content. When using DynamicHeight, the collection will wait for the actual height to be computed. Dynamic height is more flexible but less performant. |
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. |
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 (ie. tree expanded states, scroll position, zoom level). This is the key used to save/load the view data from the view data store. Not setting this key will disable persistence for this VisualElement. |
The following table lists all the C# public property names and their related USS selector.
| C# property | USS selector | 描述 |
|---|---|---|
ussClassName |
.unity-list-view |
The USS class name for ListView elements. Unity adds this USS class to every instance of the ListView element. Any styling applied to this class affects every ListView located beside, or below the stylesheet in the visual tree. |
itemUssClassName |
.unity-list-view__item |
The USS class name of item elements in ListView elements. Unity adds this USS class to every item element the ListView contains. Any styling applied to this class affects every item element located beside, or below the stylesheet in the visual tree. |
emptyLabelUssClassName |
.unity-list-view__empty-label |
The USS class name for label displayed when ListView is empty. Unity adds this USS class to the label displayed if the ListView is empty. Any styling applied to this class affects every empty label located beside, or below the stylesheet in the visual tree. |
reorderableUssClassName |
.unity-list-view__reorderable |
The USS class name for reorderable animated ListView elements. Unity adds this USS class to every instance of the ListView element when reorderMode is set to Animated. Any styling applied to this class affects every ListView located beside, or below the stylesheet in the visual tree. |
reorderableItemUssClassName |
.unity-list-view__reorderable-item |
The USS class name for item elements in reorderable animated ListView. Unity adds this USS class to every element in the ListView when reorderMode is set to Animated. Any styling applied to this class affects every element located beside, or below the stylesheet in the visual tree. |
reorderableItemContainerUssClassName |
.unity-list-view__reorderable-item__container |
The USS class name for item container in reorderable animated ListView. Unity adds this USS class to every item container in the ListView when reorderMode is set to Animated. Any styling applied to this class affects every item container located beside, or below the stylesheet in the visual tree. |
reorderableItemHandleUssClassName |
.unity-list-view__reorderable-handle |
The USS class name for drag handle in reorderable animated ListView. Unity adds this USS class to drag handles in the ListView when reorderMode is set to Animated. Any styling applied to this class affects every drag handle located beside, or below the stylesheet in the visual tree. |
reorderableItemHandleBarUssClassName |
.unity-list-view__reorderable-handle-bar |
The USS class name for drag handle bar in reorderable animated ListView. Unity adds this USS class to every drag handle bar in the ListView when reorderMode is set to Animated. Any styling applied to this class affects every drag handle bar located beside, or below the stylesheet in the visual tree. |
footerUssClassName |
.unity-list-view__footer |
The USS class name for the footer of the ListView. Unity adds this USS class to the footer element in the ListView. Any styling applied to this class affects every ListView located beside, or below the stylesheet in the visual tree. |
foldoutHeaderUssClassName |
.unity-list-view__foldout-header |
The USS class name for the foldout header of the ListView. Unity adds this USS class to the foldout element in the ListView. Any styling applied to this class affects every foldout located beside, or below the stylesheet in the visual tree. |
arraySizeFieldUssClassName |
.unity-list-view__size-field |
The USS class name for the size field of the ListView when foldout header is enabled. Unity adds this USS class to the size field element in the ListView when showFoldoutHeader is set to true. Any styling applied to this class affects every size field located beside, or below the stylesheet in the visual tree. |
listViewWithHeaderUssClassName |
.unity-list-view--with-header |
The USS class name for ListView when foldout header is enabled. Unity adds this USS class to ListView when showFoldoutHeader is set to true. Any styling applied to this class affects every list located beside, or below the stylesheet in the visual tree. |
listViewWithFooterUssClassName |
.unity-list-view--with-footer |
The USS class name for ListView when add/remove footer is enabled. Unity adds this USS class to ListView when showAddRemoveFooter is set to true. Any styling applied to this class affects every list located beside, or below the stylesheet in the visual tree. |
scrollViewWithFooterUssClassName |
.unity-list-view__scroll-view--with-footer |
The USS class name for scroll view when add/remove footer is enabled. Unity adds this USS class scroll view of BaseListViewwhen showAddRemoveFooter is set to true. Any styling applied to this class affects every list located beside, or below the stylesheet in the visual tree. |
ussClassName |
.unity-collection-view |
The USS class name for BaseVerticalCollectionView elements. Unity adds this USS class to every instance of the BaseVerticalCollectionView element. Any styling applied to this class affects every BaseVerticalCollectionView located beside, or below the stylesheet in the visual tree. |
borderUssClassName |
.unity-collection-view--with-border |
The USS class name for BaseVerticalCollectionView elements with a border. Unity adds this USS class to an instance of the BaseVerticalCollectionView element if the instance’s BaseVerticalCollectionView.showBorder property is set to true. Any styling applied to this class affects every such BaseVerticalCollectionView located beside, or below the stylesheet in the visual tree. |
itemUssClassName |
.unity-collection-view__item |
The USS class name of item elements in BaseVerticalCollectionView elements. Unity adds this USS class to every item element the BaseVerticalCollectionView contains. Any styling applied to this class affects every item element located beside, or below the stylesheet in the visual tree. |
dragHoverBarUssClassName |
.unity-collection-view__drag-hover-bar |
The USS class name of the drag hover bar. Unity adds this USS class to the bar that appears when the user drags an item in the list. Any styling applied to this class affects every BaseVerticalCollectionView located beside, or below the stylesheet in the visual tree. |
dragHoverMarkerUssClassName |
.unity-collection-view__drag-hover-marker |
The USS class name of the drag hover circular marker used to indicate depth. Unity adds this USS class to the bar that appears when the user drags an item in the list. Any styling applied to this class affects every BaseVerticalCollectionView located beside, or below the stylesheet in the visual tree. |
itemDragHoverUssClassName |
.unity-collection-view__item--drag-hover |
The USS class name applied to an item element on drag hover. Unity adds this USS class to the item element when it’s being dragged. Any styling applied to this class affects every BaseVerticalCollectionView item located beside, or below the stylesheet in the visual tree. |
itemSelectedVariantUssClassName |
.unity-collection-view__item--selected |
The USS class name of selected item elements in the BaseVerticalCollectionView. Unity adds this USS class to every selected element in the BaseVerticalCollectionView. The BaseVerticalCollectionView.selectionType property decides if zero, one, or more elements can be selected. Any styling applied to this class affects every BaseVerticalCollectionView item located beside, or below the stylesheet in the visual tree. |
itemAlternativeBackgroundUssClassName |
.unity-collection-view__item--alternative-background |
The USS class name for odd rows in the BaseVerticalCollectionView. Unity adds this USS class to every odd-numbered item in the BaseVerticalCollectionView when the BaseVerticalCollectionView.showAlternatingRowBackgrounds property is set to ContentOnly or All. When the showAlternatingRowBackgrounds property is set to either of those values, odd-numbered items are displayed with a different background color than even-numbered items. This USS class is used to differentiate odd-numbered items from even-numbered items. When the showAlternatingRowBackgrounds property is set to None, the USS class is not added, and any styling or behavior that relies on it’s invalidated. |
listScrollViewUssClassName |
.unity-collection-view__scroll-view |
The USS class name of the scroll view in the BaseVerticalCollectionView. Unity adds this USS class to the BaseVerticalCollectionView’s scroll view. Any styling applied to this class affects every BaseVerticalCollectionView scroll view located beside, or below the stylesheet in the visual tree. |
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.