# RadioGroup.OnCheckedChangeListener

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)

# OnCheckedChangeListener

*** ** * ** ***

Kotlin\|[Java](https://developer.android.com/reference/android/widget/RadioGroup.OnCheckedChangeListener "View this page in Java")  

```
interface OnCheckedChangeListener
```

|--------------------------------------------------------------------------------------------------------------------------------------------------------|
| [android.widget.RadioGroup.OnCheckedChangeListener](https://developer.android.com/reference/kotlin/android/widget/RadioGroup.OnCheckedChangeListener#) |

Interface definition for a callback to be invoked when the checked radio button changed in this group.

## Summary

|                                                                                                                                                                                                                                                     Public methods                                                                                                                                                                                                                                                     ||
|--------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| abstract[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [onCheckedChanged](https://developer.android.com/reference/kotlin/android/widget/RadioGroup.OnCheckedChangeListener#onCheckedChanged(android.widget.RadioGroup,%20kotlin.Int))`(`group:` `[RadioGroup](https://developer.android.com/reference/kotlin/android/widget/RadioGroup)`, `checkedId:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Called when the checked radio button has changed. |

## Public methods

### onCheckedChanged

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)  

```
abstract fun onCheckedChanged(
    group: RadioGroup, 
    checkedId: Int
): Unit
```

Called when the checked radio button has changed. When the selection is cleared, checkedId is -1.

|                                                                                       Parameters                                                                                        ||
|-------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `group`     | [RadioGroup](https://developer.android.com/reference/kotlin/android/widget/RadioGroup):the group in which the checked radio button has changed This value cannot be`null`. |
| `checkedId` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):the unique identifier of the newly checked radio button                                         |