# ViewPager.OnAdapterChangeListener

# ViewPager.OnAdapterChangeListener

Artifact:[androidx.viewpager:viewpager](https://developer.android.com/jetpack/androidx/releases/viewpager)  
[View Source](https://cs.android.com/search?q=file:androidx/viewpager/widget/ViewPager.java+class:androidx.viewpager.widget.ViewPager.OnAdapterChangeListener)  
Added in[1.1.0](https://developer.android.com/jetpack/androidx/releases/viewpager#1.1.0)

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Kotlin\|[Java](https://developer.android.com/reference/androidx/viewpager/widget/ViewPager.OnAdapterChangeListener "View this page in Java")

<br />

```
interface ViewPager.OnAdapterChangeListener
```

<br />

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Callback interface for responding to adapter changes.

## Summary

|                             ### Public functions                              |
|-------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [Unit](https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-unit/index.html) | [onAdapterChanged](https://developer.android.com/reference/kotlin/androidx/viewpager/widget/ViewPager.OnAdapterChangeListener#onAdapterChanged(androidx.viewpager.widget.ViewPager,androidx.viewpager.widget.PagerAdapter,androidx.viewpager.widget.PagerAdapter))`(` ` viewPager: `[ViewPager](https://developer.android.com/reference/kotlin/androidx/viewpager/widget/ViewPager)`,` ` oldAdapter: `[PagerAdapter](https://developer.android.com/reference/kotlin/androidx/viewpager/widget/PagerAdapter)`?,` ` newAdapter: `[PagerAdapter](https://developer.android.com/reference/kotlin/androidx/viewpager/widget/PagerAdapter)`?` `)` Called when the adapter for the given view pager has changed. |

## Public functions

### onAdapterChanged

Added in[1.1.0](https://developer.android.com/jetpack/androidx/releases/viewpager#1.1.0)  

```
fun onAdapterChanged(
    viewPager: ViewPager,
    oldAdapter: PagerAdapter?,
    newAdapter: PagerAdapter?
): Unit
```

Called when the adapter for the given view pager has changed.  

|                                                       Parameters                                                       |
|------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------|
| `viewPager: `[ViewPager](https://developer.android.com/reference/kotlin/androidx/viewpager/widget/ViewPager)           | ViewPager where the adapter change has happened |
| `oldAdapter: `[PagerAdapter](https://developer.android.com/reference/kotlin/androidx/viewpager/widget/PagerAdapter)`?` | the previously set adapter                      |
| `newAdapter: `[PagerAdapter](https://developer.android.com/reference/kotlin/androidx/viewpager/widget/PagerAdapter)`?` | the newly set adapter                           |