ViewModelProvider
public
class
ViewModelProvider
extends Object
java.lang.Object | |
↳ | androidx.lifecycle.ViewModelProvider |
An utility class that provides ViewModels
for a scope.
Default ViewModelProvider
for an Activity
or a Fragment
can be obtained
by passing it to ViewModelProvider(ViewModelStoreOwner)
.
Summary
Nested classes | |
---|---|
class |
ViewModelProvider.AndroidViewModelFactory
|
interface |
ViewModelProvider.Factory
Implementations of |
class |
ViewModelProvider.NewInstanceFactory
Simple factory, which calls empty constructor on the give class. |
Public constructors | |
---|---|
ViewModelProvider(ViewModelStoreOwner owner)
Creates |
|
ViewModelProvider(ViewModelStoreOwner owner, ViewModelProvider.Factory factory)
Creates |
|
ViewModelProvider(ViewModelStore store, ViewModelProvider.Factory factory)
Creates |
Public methods | |
---|---|
<T extends ViewModel>
T
|
get(Class<T> modelClass)
Returns an existing ViewModel or creates a new one in the scope (usually, a fragment or
an activity), associated with this |
<T extends ViewModel>
T
|
get(String key, Class<T> modelClass)
Returns an existing ViewModel or creates a new one in the scope (usually, a fragment or
an activity), associated with this |
Inherited methods | |
---|---|
Public constructors
ViewModelProvider
public ViewModelProvider (ViewModelStoreOwner owner)
Creates ViewModelProvider
. This will create ViewModels
and retain them in a store of the given ViewModelStoreOwner
.
This method will use the
default factory
if the owner implements HasDefaultViewModelProviderFactory
. Otherwise, a
ViewModelProvider.NewInstanceFactory
will be used.
Parameters | |
---|---|
owner |
ViewModelStoreOwner |
ViewModelProvider
public ViewModelProvider (ViewModelStoreOwner owner, ViewModelProvider.Factory factory)
Creates ViewModelProvider
, which will create ViewModels
via the given
Factory
and retain them in a store of the given ViewModelStoreOwner
.
Parameters | |
---|---|
owner |
ViewModelStoreOwner : a ViewModelStoreOwner whose ViewModelStore will be used to
retain ViewModels |
factory |
ViewModelProvider.Factory : a Factory which will be used to instantiate
new ViewModels
|
ViewModelProvider
public ViewModelProvider (ViewModelStore store, ViewModelProvider.Factory factory)
Creates ViewModelProvider
, which will create ViewModels
via the given
Factory
and retain them in the given store
.
Parameters | |
---|---|
store |
ViewModelStore : ViewModelStore where ViewModels will be stored. |
factory |
ViewModelProvider.Factory : factory a Factory which will be used to instantiate
new ViewModels
|
Public methods
get
public T get (Class<T> modelClass)
Returns an existing ViewModel or creates a new one in the scope (usually, a fragment or
an activity), associated with this ViewModelProvider
.
The created ViewModel is associated with the given scope and will be retained as long as the scope is alive (e.g. if it is an activity, until it is finished or process is killed).
Parameters | |
---|---|
modelClass |
Class : The class of the ViewModel to create an instance of it if it is not
present. |
Returns | |
---|---|
T |
A ViewModel that is an instance of the given type T .
|
get
public T get (String key, Class<T> modelClass)
Returns an existing ViewModel or creates a new one in the scope (usually, a fragment or
an activity), associated with this ViewModelProvider
.
The created ViewModel is associated with the given scope and will be retained as long as the scope is alive (e.g. if it is an activity, until it is finished or process is killed).
Parameters | |
---|---|
key |
String : The key to use to identify the ViewModel. |
modelClass |
Class : The class of the ViewModel to create an instance of it if it is not
present. |
Returns | |
---|---|
T |
A ViewModel that is an instance of the given type T .
|
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Last updated 2021-02-24 UTC.