Version: 2021.3
Language : English
UXML element PropertyField
UXML element RadioButtonGroup

UXML element RadioButton

A RadioButton lets users select a single choice when used along with other RadioButtons in a group. You can use a GroupBox to group RadioButtons. Otherwise, the panel acts as the default group.

Note: To align an element with other fields in an InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info
See in Glossary
window, simply apply the .unity-base-field__aligned USS class to it. For more information, refer to BaseField.

Create a RadioButton

You can create a RadioButton with UI(User Interface) Allows a user to interact with your application. Unity currently supports three UI systems. More info
See in Glossary
Builder, UXML, or C#. The following C# example creates two new radio buttons in the same container and logically groups them together in the panel.

var choice1 = new RadioButton() { text = "Choice 1" };
choice1.RegisterValueChangedCallback(v => Debug.Log("Choice 1 is : " + v.newValue));
var choice2 = new RadioButton() { text = "Choice 2" };
choice2.RegisterValueChangedCallback(v => Debug.Log("Choice 2 is : " + v.newValue));
container.Add(choice1);
container.Add(choice2);

Examples

The following UXML example creates a RadioButton:

<UXML xmlns="UnityEngine.UIElements" xmlns:uie="UnityEditor.UIElements">
    <GroupBox>
        <RadioButton label="UXML Field 1" name="the-uxml-field1" />
        <RadioButton label="UXML Field 2" name="the-uxml-field2" />
    </GroupBox>
</UXML>

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

/// <sample>
// Note: See also RadioButtonGroup in the ChoiceField section of UI Toolkit Samples

// Get a reference to the first radio button from UXML and assign it its value.
var uxmlField1 = container.Q<RadioButton>("the-uxml-field1");
var uxmlField2 = container.Q<RadioButton>("the-uxml-field2");
uxmlField1.value = true;

// Create two RadioButtons in a separate group, disable them, and give them a style class.
var groupBox = new GroupBox();
container.Add(groupBox);

var csharpField1 = new RadioButton("C# Field 1");
csharpField1.SetEnabled(false);
csharpField1.AddToClassList("some-styled-field");
groupBox.Add(csharpField1);

var csharpField2 = new RadioButton("C# Field 2");
csharpField2.SetEnabled(false);
csharpField2.AddToClassList("some-styled-field");
groupBox.Add(csharpField2);

csharpField1.value = uxmlField1.value;

// Mirror value of uxml field into the C# field.
uxmlField1.RegisterCallback<ChangeEvent<bool>>((evt) =>
{
    csharpField1.value = evt.newValue;
});
uxmlField2.RegisterCallback<ChangeEvent<bool>>((evt) =>
{
    csharpField2.value = evt.newValue;
});
/// </sample>

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

C# class and namespace

C# class: RadioButton
Namespace: UnityEngine.UIElements
Base class: BaseBoolField

Inherited attributes

This element inherits the following attributes from its base class:

Name Type Description
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.
text string Optional text that appears after the BaseBoolField.

Unity creates a Label automatically if one does not exist.
value boolean The value associated with the field.

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.
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.
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 Description
ussClassName .unity-radio-button USS class name for RadioButton elements.

Unity adds this USS class to every instance of the RadioButton element. Any styling applied to this class affects every RadioButton located beside, or below the stylesheet in the visual tree.
labelUssClassName .unity-radio-button__label USS class name for Labels in RadioButton elements.

Unity adds this USS class to the Label sub-element of the RadioButton if the RadioButton has a Label.
inputUssClassName .unity-radio-button__input USS class name of input elements in RadioButton elements.

Unity adds this USS class to the input sub-element of the RadioButton. The input sub-element provides responses to the manipulator.
checkmarkBackgroundUssClassName .unity-radio-button__checkmark-background USS class name of checkmark background in RadioButton elements.

Unity adds this USS class to the checkmark background sub-element of the RadioButton.
checkmarkUssClassName .unity-radio-button__checkmark USS class name of checkmark in RadioButton elements.

Unity adds this USS class to the checkmark sub-element of the RadioButton.
textUssClassName .unity-radio-button__text USS class name of Text elements in RadioButton elements.

Unity adds this USS class to Text sub-elements of the RadioButton.
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.

Additional resources

UXML element PropertyField
UXML element RadioButtonGroup