Activity.OnSaveInstanceState Method

Definition

Namespace:: Android.App

Assembly:: Mono.Android.dll

Important

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Overloads

Name	Description
OnSaveInstanceState(Bundle)	Called to retrieve per-instance state from an activity before being killed so that the state can be restored in onCreate(Bundle) or onRestoreInstanceState(Bundle) (the Bundle populated by this method will be passed to both).
OnSaveInstanceState(Bundle, PersistableBundle)	This is the same as onSaveInstanceState(Bundle) but is called for activities created with the attribute R.attr.persistableMode set to persistAcrossReboots.

OnSaveInstanceState(Bundle)

[Android.Runtime.Register("onSaveInstanceState", "(Landroid/os/Bundle;)V", "GetOnSaveInstanceState_Landroid_os_Bundle_Handler")]
protected virtual void OnSaveInstanceState(Android.OS.Bundle outState);

[<Android.Runtime.Register("onSaveInstanceState", "(Landroid/os/Bundle;)V", "GetOnSaveInstanceState_Landroid_os_Bundle_Handler")>]
abstract member OnSaveInstanceState : Android.OS.Bundle -> unit
override this.OnSaveInstanceState : Android.OS.Bundle -> unit

Parameters

outState: Bundle

Bundle: Bundle in which to place your saved state. This value cannot be null.

Attributes: RegisterAttribute

Remarks

Called to retrieve per-instance state from an activity before being killed so that the state can be restored in onCreate(Bundle) or onRestoreInstanceState(Bundle) (the Bundle populated by this method will be passed to both). This method is called before an activity may be killed so that when it comes back some time in the future it can restore its state. For example, if activity B is launched in front of activity A, and at some point activity A is killed to reclaim resources, activity A will have a chance to save the current state of its user interface via this method so that when the user returns to activity A, the state of the user interface can be restored via onCreate(Bundle) or onRestoreInstanceState(Bundle). Do not confuse this method with activity lifecycle callbacks such as onPause(), which is always called when the user no longer actively interacts with an activity, or onStop() which is called when activity becomes invisible. One example of when onPause() and onStop() is called and not this method is when a user navigates back from activity B to activity A: there is no need to call onSaveInstanceState(Bundle) on B because that particular instance will never be restored, so the system avoids calling it. An example when onPause() is called and not onSaveInstanceState(Bundle) is when activity B is launched in front of activity A: the system may avoid calling onSaveInstanceState(Bundle) on activity A if it isn't killed during the lifetime of B since the state of the user interface of A will stay intact. The default implementation takes care of most of the UI per-instance state for you by calling View.onSaveInstanceState() on each view in the hierarchy that has an id, and by saving the id of the currently focused view (all of which is restored by the default implementation of onRestoreInstanceState(Bundle)). If you override this method to save additional information not captured by each individual view, you will likely want to call through to the default implementation, otherwise be prepared to save all of the state of each view yourself. If called, this method will occur after onStop() for applications targeting platforms starting with Build.VERSION_CODES.P. For applications targeting earlier platform versions this method will occur before onStop() and there are no guarantees about whether it will occur before or after onPause().

Applies to

OnSaveInstanceState(Bundle, PersistableBundle)

This is the same as onSaveInstanceState(Bundle) but is called for activities created with the attribute R.attr.persistableMode set to persistAcrossReboots.

[Android.Runtime.Register("onSaveInstanceState", "(Landroid/os/Bundle;Landroid/os/PersistableBundle;)V", "GetOnSaveInstanceState_Landroid_os_Bundle_Landroid_os_PersistableBundle_Handler")]
public virtual void OnSaveInstanceState(Android.OS.Bundle outState, Android.OS.PersistableBundle outPersistentState);

[<Android.Runtime.Register("onSaveInstanceState", "(Landroid/os/Bundle;Landroid/os/PersistableBundle;)V", "GetOnSaveInstanceState_Landroid_os_Bundle_Landroid_os_PersistableBundle_Handler")>]
abstract member OnSaveInstanceState : Android.OS.Bundle * Android.OS.PersistableBundle -> unit
override this.OnSaveInstanceState : Android.OS.Bundle * Android.OS.PersistableBundle -> unit

Parameters

outState: Bundle

Bundle: Bundle in which to place your saved state. This value cannot be null.

outPersistentState: PersistableBundle

PersistableBundle: State which will be saved across reboots. This value cannot be null.

Attributes: RegisterAttribute

Remarks

This is the same as onSaveInstanceState(Bundle) but is called for activities created with the attribute R.attr.persistableMode set to persistAcrossReboots. The PersistableBundle passed in will be saved and presented in onCreate(Bundle,PersistableBundle) the first time that this activity is restarted following the next device reboot.

Applies to