The Radio Button control is used to allow the user to select from among a set of mutually exclusive options. It is therefore designed to be grouped with other Radio Buttons. The Radio Button is mutually exclusive with other Radio Buttons in the same group, meaning that within a group, only a single Radio Button can hold a value of True at one time. By default, Radio Buttons are grouped together by parent. That is, all Radio Buttons which share the same parent GameObject are considered to be part of the same mutually exclusive group.

This behavior can be changed by unchecking the "Use Parent For Grouping" option, in which case, you should specify an ID number in the "Radio Group" field which will assign the radio button to that grouping. All radio buttons which share a common "Radio Group" number will be mutually exlusive.

UIRadioBtn
UIRadioBtn3D

The Radio Button control type executes code in response to user input by invoking a method on a MonoBehavior (specified by setting the "Script With Method To Invoke" and "Method To Invoke" properties), and/or by calling a delegate, set by calling the SetInputDelegate() or AddInputDelegate() methods through script.

When then value of the control changes as a result of user input, any registered EZValueChangedDelegate delegate will be called.

You can set and retrieve the current value of the control through the Value property.

Use Parent For Grouping - When true, the button will be mutually exclusive to other radio buttons that share the same parent GameObject. Otherwise, you manually specify the group ID ("Radio Group") of the radio button, and all radios that share the same group ID are mutually exclusive.

Radio Group - Only used if Use Parent For Grouping is set to false. In this case, you can assign a group ID number in this field. All radio buttons in the scene which have the same Radio Group value will be mutually exclusive.

Default Value - The value to which the button should default (boolean).

Sound To Play - The sound to be played when the button is tapped.

Disable Hover Effect - When false, any "layer" that is set will be assumed to contain states for "Over" and "Active" so as to provide visuals for the "Hover" effect, as well as the "Active" (pressed) effect. When true, however, the layers are assumed to only be used to mirror the control's current state/value, and will not provide "Over" and "Active" state appearances. For more details, see here.

true	State when the control's value is true.
false	State when the control's value is false.
disabled	State when the control is disabled.
...	While there is no "Over" state for this control, you can achieve a "hover" appearance when the pointer is over the control by using the technique described in the Advanced topic, Hover Effects for Radios and Toggles.