# ActivityLifecycleMonitorRegistry

# ActivityLifecycleMonitorRegistry

Artifact:[androidx.test:monitor](https://developer.android.com/jetpack/androidx/releases/test)  
[View Source](https://cs.android.com/search?q=file:androidx/test/runner/lifecycle/ActivityLifecycleMonitorRegistry.java+class:androidx.test.runner.lifecycle.ActivityLifecycleMonitorRegistry)

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Kotlin\|[Java](https://developer.android.com/reference/androidx/test/runner/lifecycle/ActivityLifecycleMonitorRegistry "View this page in Java")

<br />

```
class ActivityLifecycleMonitorRegistry
```

<br />

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An exposed registry instance to make it easy for callers to find the lifecycle monitor for their application.

## Summary

|                                                                ### Public functions                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `java-static `[ActivityLifecycleMonitor](https://developer.android.com/reference/kotlin/androidx/test/runner/lifecycle/ActivityLifecycleMonitor)`!` | [getInstance](https://developer.android.com/reference/kotlin/androidx/test/runner/lifecycle/ActivityLifecycleMonitorRegistry#getInstance())`()` Returns the ActivityLifecycleMonitor.                                                                                                                                                                                                                      |
| `java-static `[Unit](https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-unit/index.html)                                                         | [registerInstance](https://developer.android.com/reference/kotlin/androidx/test/runner/lifecycle/ActivityLifecycleMonitorRegistry#registerInstance(androidx.test.runner.lifecycle.ActivityLifecycleMonitor))`(monitor: `[ActivityLifecycleMonitor](https://developer.android.com/reference/kotlin/androidx/test/runner/lifecycle/ActivityLifecycleMonitor)`!)` Stores a lifecycle monitor in the registry. |

## Public functions

### getInstance

```
java-static fun getInstance(): ActivityLifecycleMonitor!
```

Returns the ActivityLifecycleMonitor.

This monitor is not guaranteed to be present under all instrumentations.  

|                                                                Returns                                                                |
|---------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------|
| [ActivityLifecycleMonitor](https://developer.android.com/reference/kotlin/androidx/test/runner/lifecycle/ActivityLifecycleMonitor)`!` | ActivityLifecycleMonitor the monitor for this application. |

|                                                     Throws                                                      |
|-----------------------------------------------------------------------------------------------------------------|------------------------------------|
| [java.lang.IllegalStateException](https://developer.android.com/reference/java/lang/IllegalStateException.html) | if no monitor has been registered. |

### registerInstance

```
java-static fun registerInstance(monitor: ActivityLifecycleMonitor!): Unit
```

Stores a lifecycle monitor in the registry.

This is a global registry - so be aware of the impact of calling this method!  

|                                                                    Parameters                                                                    |
|--------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------|
| `monitor: `[ActivityLifecycleMonitor](https://developer.android.com/reference/kotlin/androidx/test/runner/lifecycle/ActivityLifecycleMonitor)`!` | the monitor for this application. Null deregisters any existing monitor. |