UXML element MultiColumnListView

A MultiColumnListView is a UI(User Interface) Allows a user to interact with your application. Unity currently supports three UI systems. More info
See in Glossary control commonly used to display tabular or grid-like data with multiple columns. It allows you to present data in a structured format, where each row represents an item or entry, and each column represents a specific attribute or property of that item.

Create a MultiColumnListView

You can create a MultiColumnListView with UXML and C#. The following C# example creates a MultiColumnListView with two columns:

var multiColumnListView = new MultiColumnListView();
multiColumnListView.columns.Add(new Column { title = "Name", width = 20 });
multiColumnListView.columns.Add(new Column { title = "Power", width = 80 });

Refresh the collection view

To refresh the collection view, in general, call the RefreshItems or RefreshItem method. However, in the following cases, call Rebuild instead to refresh the collection view:

• You change the type of the data source, such as changing from a List<float> to a List<Vector3>.
• You make changes to makeItem or destroyItem.

Note: If you call Rebuild, the collection view is completely rebuilt, which can be expensive. If you call RefreshItems or RefreshItem, the collection view is only refreshed, which is less expensive.

Bind the MultiColumnListView to data

You can bind the MultiColumnListView to a data source, and automatically populate the rows and columns based on the provided data. Refer to Create list and tree views for an example.

Sort the MultiColumnListView

You enable sorting for MultiColumnListView. Once enabled, you can click the column headers to sort. To sort multiple columns, hold down the Ctrl key (macOS: Cmd) and click.

To enable sorting:

1. Set the sortingEnabled attribute to true.
2. Use the sortColumnDescriptions attribute to define the initial column to sort by. Setting a value for this attribute is optional. If you don’t set a value, the MultiColumnListView sorts by the first column by default.

To reorder:

1. Register to columnSortingChanged and implement how sorting applies to your source.
2. In the callback, use sortColumns to reorder your list accordingly and trigger a RefreshItems() once the items’ source has been updated.

The sortColumns attribute is the current state of sorted columns. The sortColumns list is in order in which columns were sorted. If you sort by column 1, then column 2, then column 3, the sortedColumns list is [1, 2, 3]. If you sort by column 3, then column 2, then column 1, the sortedColumns list is [3, 2, 1].

Implement drag-and-drop operations for MultiColumnListView

Drag-and-drop is a common feature in UI design. To implement the drag-and-drop operations, override the following methods:

• To enable dragging items, override canStartDrag.
• To set which items are dragged, override setupDragAndDrop.
• To get item status changes, override dragAndDropUpdate. You can perform certain actions based on the drag position or other conditions.
• To control the drag-and-drop behavior, override handleDrop.

During the drag-and-drop operation, you can enable the reordering of items by dragging. To enable, set the reorderable attribute to true in UI Builder, UXML, and C#.

Refer to Create a drag-and-drop list and tree views between windows for an example.

Examples

• Create list and tree views: Use ListView, TreeView, MultiColumnListView, and MultiColumnTreeView to create list and tree views.
• Create a drag-and-drop list and tree views between windows: Use ListView, TreeView, and MultiColumnListView to create a drag-and-drop UI between windows.

C# base class and namespace

C# class: MultiColumnListView
Namespace: UnityEngine.UIElements
Base class: BaseListView

Member UXML attributes

This element has the following member attributes:

Name	Type	Description
columns	UIElements.Columns+UxmlSerializedData	The collection of columns for the multi-column header.
sort-column-descriptions	UIElements.SortColumnDescriptions+UxmlSerializedData	The collection of sorted columns by default.
sorting-enabled	boolean	Whether or not sorting is enabled in the multi-column header. This is deprecated. Use sortingMode instead.
sorting-mode	UIElements.ColumnSortingMode	Indicates how to sort columns. To enable sorting, set it to ColumnSortingMode.Default or ColumnSortingMode.Custom. The Default mode uses the sorting algorithm provided by MultiColumnController, acting on indices. You can also implement your own sorting with the Custom mode, by responding to the columnSortingChanged event. Note: If there is at least one sorted column, reordering is temporarily disabled.

Inherited UXML attributes

This element inherits the following attributes from its base class:

Name	Type	Description
allow-add	boolean	This property allows the user to allow or block the addition of an item when clicking on the Add Button. It must return true or false. If the callback is not set to false, any Add operation will be allowed.
allow-remove	boolean	This property allows the user to allow or block the removal of an item when clicking on the Remove Button. It must return true or false. If the property is not set to false, any Remove operation will be allowed.
binding-path	string	Path of the target property to be bound.
binding-source-selection-mode	UIElements.BindingSourceSelectionMode	This property controls whether every element in the list will get its data source setup automatically to the correct item in the collection’s source. When set to AutoAssign, the bind callbacks don’t need to be specified, since bindings can be used to fill the elements.
fixed-item-height	float	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. If the makeHeader callback is set, this property gets overridden and the title is not shown.
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. If the makeFooter callback is set, it will override this property.
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 to true, the ListView includes a TextField to control the array size. 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 ListView includes a TextField to control the array size. If the makeHeader callback is set, no Foldout is shown.
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:

Name	Type	Description
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.
data-source-type	System.Type	The possible type of data source assignable to this VisualElement. This information is only used by the UI Builder as a hint to provide some completion to the data source path field when the effective data source cannot be specified at design time.
language-direction	UIElements.LanguageDirection	Indicates the directionality of the element’s text. The value will propagate to the element’s children. Setting the languageDirection to RTL adds basic support for right-to-left (RTL) by reversing the text and handling linebreaking and word wrapping appropriately. However, it does not provide comprehensive RTL support, as this would require text shaping, which includes the reordering of characters, and OpenType font feature support. Comprehensive RTL support is planned for future updates, which will involve additional APIs to handle language, script, and font feature specifications. To enhance the RTL functionality of this property, users can explore available third-party plugins in the Unity Asset Store and make use of ITextElementExperimentalFeatures.renderedText
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	Sets the VisualElement style values.
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	Description
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 show bound collection size is enabled Unity adds this USS class to the size field element in the ListView when showBoundCollectionSize is set to true. Any styling applied to this class affects every size field located beside, or below the stylesheet in the visual tree.
arraySizeFieldWithHeaderUssClassName	.unity-list-view__size-field--with-header	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 showBoundCollectionSize is set to true. Any styling applied to this class affects every size field located beside, or below the stylesheet in the visual tree.
arraySizeFieldWithFooterUssClassName	.unity-list-view__size-field--with-footer	The USS class name for the size field of the ListView when the footer is enabled. Unity adds this USS class to the size field element in the ListView when showBoundCollectionSize 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.

Additional resources

• ListView
• TreeView
• ScrollViewA UI Control which displays a large set of Controls in a viewable area that you can see by using a scrollbar. More info
  See in Glossary
• MultiColumnTreeView