Added in [API level 30](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Ctors](https://developer.android.com/reference/android/os/storage/StorageManager.StorageVolumeCallback#pubctors) \| [Methods](https://developer.android.com/reference/android/os/storage/StorageManager.StorageVolumeCallback#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/android/os/storage/StorageManager.StorageVolumeCallback#inhmethods)

# StorageManager.StorageVolumeCallback

*** ** * ** ***

` public static class StorageManager.StorageVolumeCallback `   
` extends https://developer.android.com/reference/java/lang/Object ` ` `

|---|---|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||
| ↳ | android.os.storage.StorageManager.StorageVolumeCallback |

<br />

*** ** * ** ***

Callback that delivers `https://developer.android.com/reference/android/os/storage/StorageVolume` related events.

For example, this can be used to detect when a volume changes to the `https://developer.android.com/reference/android/os/Environment#MEDIA_MOUNTED` or `https://developer.android.com/reference/android/os/Environment#MEDIA_UNMOUNTED` states.
**See also:**

- `https://developer.android.com/reference/android/os/storage/StorageManager#registerStorageVolumeCallback(java.util.concurrent.Executor,%20android.os.storage.StorageManager.StorageVolumeCallback)`
- `https://developer.android.com/reference/android/os/storage/StorageManager#unregisterStorageVolumeCallback(android.os.storage.StorageManager.StorageVolumeCallback)`

## Summary

| ### Public constructors ||
|---|---|
| ` https://developer.android.com/reference/android/os/storage/StorageManager.StorageVolumeCallback#StorageVolumeCallback()() ` |

| ### Public methods ||
|---|---|
| ` void` | ` https://developer.android.com/reference/android/os/storage/StorageManager.StorageVolumeCallback#onStateChanged(android.os.storage.StorageVolume)(https://developer.android.com/reference/android/os/storage/StorageVolume volume) ` Called when `https://developer.android.com/reference/android/os/storage/StorageVolume#getState()` changes, such as changing to the `https://developer.android.com/reference/android/os/Environment#MEDIA_MOUNTED` or `https://developer.android.com/reference/android/os/Environment#MEDIA_UNMOUNTED` states. |

### Inherited methods

From class ` https://developer.android.com/reference/java/lang/Object ` ` https://developer.android.com/reference/java/lang/Object` ` https://developer.android.com/reference/java/lang/Object#clone()() `

Creates and returns a copy of this object.
` boolean` ` https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj) `

Indicates whether some other object is "equal to" this one.
` void` ` https://developer.android.com/reference/java/lang/Object#finalize()() `

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
` final https://developer.android.com/reference/java/lang/Class<?>` ` https://developer.android.com/reference/java/lang/Object#getClass()() `

Returns the runtime class of this `Object`.
` int` ` https://developer.android.com/reference/java/lang/Object#hashCode()() `

Returns a hash code value for the object.
` final void` ` https://developer.android.com/reference/java/lang/Object#notify()() `

Wakes up a single thread that is waiting on this object's monitor.
` final void` ` https://developer.android.com/reference/java/lang/Object#notifyAll()() `

Wakes up all threads that are waiting on this object's monitor.
` https://developer.android.com/reference/java/lang/String` ` https://developer.android.com/reference/java/lang/Object#toString()() `

Returns a string representation of the object.
` final void` ` https://developer.android.com/reference/java/lang/Object#wait(long,%20int)(long timeoutMillis, int nanos) `

Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed.
` final void` ` https://developer.android.com/reference/java/lang/Object#wait(long)(long timeoutMillis) `

Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed.
` final void` ` https://developer.android.com/reference/java/lang/Object#wait()() `

Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*.

## Public constructors

### StorageVolumeCallback

```
public StorageVolumeCallback ()
```

<br />

<br />

## Public methods

### onStateChanged

Added in [API level 30](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void onStateChanged (StorageVolume volume)
```

Called when `https://developer.android.com/reference/android/os/storage/StorageVolume#getState()` changes, such as changing to the `https://developer.android.com/reference/android/os/Environment#MEDIA_MOUNTED` or `https://developer.android.com/reference/android/os/Environment#MEDIA_UNMOUNTED` states.

The given argument is a snapshot in time and can be used to process events in the order they occurred, or you can call `https://developer.android.com/reference/android/os/storage/StorageManager#getStorageVolumes()` to observe the latest value.

<br />

| Parameters ||
|---|---|
| `volume` | `StorageVolume`: This value cannot be `null`. <br /> |