UXML element RadioButtonGroup

A RadioButtonGroup offers a single selection out of a logical group of radio buttons. Selecting one cancels the others. RadioButtonGroup is similar to a DropdownField except that it expose all choices in the UI.

Respond to user actions

A RadioButtonGroup responds to Change events.

You can bind a RadioButtonGroup to an Integer variable or evaluate its value passively, but typically you define the list of choices and listen for user input.

Add options for a RadioButtonGroup in UI Builder

To add options for a RadioButtonGroup, in the Inspector of the RadioButtonGroup, enter the options separated by commas in Choices.

To set the default value, in the Inspector of the RadioButtonGroup, enter the numbering sequence of the option in Value, starting at 0.

Create a RadioButtonGroup in C# script

The following C# code snippets create a new RadioButtonGroup with four options and register to its value changed callback.

var radiogroup = new RadioButtonGroup("Options", new List<string> { "Option 1", "Option 2", "Option 3", "Option 4" });
radiogroup.RegisterValueChangedCallback(evt => Debug.Log(evt.newValue));
window.rootVisualElement.Add(radiogroup);

示例

The best way to learn how to use RadioButton is to try an example. To see a RadioButton example, in Unity, select Window > UI Toolkit > Samples > RadioButtonGroup.

C# class and namespace

C# class: RadioButtonGroup
Namespace: UnityEngine.UIElements
Base class: BaseField_1

Member UXML attributes

This element has the following member attributes:

名称	类型	描述
`choices`	`string`	The list of available choices in the group. Writing to this property removes existing `RadioButton` elements and re-creates them to display the new list.

Inherited UXML attributes

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.
`focusable`	`boolean`	True if the element can be focused.
`label`	`string`	The string representing the label that will appear beside the field.
`tabindex`	`int`	An integer used to sort focusables in the focus ring. Must be greater than or equal to zero.
`value`	`int`	The value associated with the field.

This element also inherits the following attributes from VisualElement:

名称	类型	描述
`content-container`	`string`	child elements are added to this element, usually this
`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`.

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-radio-button-group`	USS class name for RadioButtonGroup elements. Unity adds this USS class to every instance of the RadioButtonGroup element. Any styling applied to this class affects every RadioButtonGroup located beside, or below the stylesheet in the visual tree.
`containerUssClassName`	`.unity-radio-button-group__container`	USS class name of container element of this type.
`ussClassName`	`.unity-base-field`	USS class name of elements of this type.
`labelUssClassName`	`.unity-base-field__label`	USS class name of labels in elements of this type.
`inputUssClassName`	`.unity-base-field__input`	USS class name of input elements in elements of this type.
`noLabelVariantUssClassName`	`.unity-base-field--no-label`	USS class name of elements of this type, when there is no label.
`labelDraggerVariantUssClassName`	`.unity-base-field__label--with-dragger`	USS class name of labels in elements of this type, when there is a dragger attached on them.
`mixedValueLabelUssClassName`	`.unity-base-field__label--mixed-value`	USS class name of elements that show mixed values
`alignedFieldUssClassName`	`.unity-base-field__aligned`	USS class name of elements that are aligned in a inspector element
`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

UXML element RadioButton

UXML element RectField