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 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.

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

• 更改事件
• RadioButton