Android 消息总站 设计思路

项目是组件化模式，这里记录下项目消息总站设计思路

目录

1、接口模式

2、Viewmodel 模式

3、LiveDataBus 模式

3、EventBus 模式

---

1、接口模式

消息总站：MessageCenter 单利模式

public class MessageCenter {private static MessageCenter instance;private final List<Notifiable> observers = new ArrayList<>();private MessageCenter() {}public static synchronized MessageCenter getInstance() {if (instance == null) {instance = new MessageCenter();}return instance;}public void addObserver(Notifiable observer) {observers.add(observer);}public void removeObserver(Notifiable observer) {observers.remove(observer);}public void notifyObservers(String message) {for (Notifiable observer : observers) {observer.onNotify(message);}}
}

Notifiable 接口

public interface Notifiable {void onNotify(String message);
}

使用：

发送消息

MessageCenter.getInstance().notifyObservers("测试消息");

接收消息

实现接口：implements Notifiable

添加观察者：MessageCenter.getInstance().addObserver(this);

实现回调方法：

@Override
public void onNotify(String message) {}

2、Viewmodel 模式

使用 LiveData 和 Lifecycle 来实现消息中心

实现步骤：

定义消息中心

public class MessageViewModel extends ViewModel {private final MutableLiveData<String> message = new MutableLiveData<>();public void sendMessage(String msg) {message.setValue(msg);}public LiveData<String> getMessage() {return message;}
}

为了在应用程序级别共享 ViewModel，我们需要定义一个 ViewModelProvider.Factory

public class ViewModelFactory implements ViewModelProvider.Factory {@NonNull@Overridepublic <T extends ViewModel> T create(@NonNull Class<T> modelClass) {if (modelClass.isAssignableFrom(MessageViewModel.class)) {return (T) new MessageViewModel();}throw new IllegalArgumentException("Unknown ViewModel class");}
}

创建一个单例类来管理 ViewModelProvider，以便在组件化模式下使用

public class ViewModelProviderManager implements ViewModelStoreOwner {private static ViewModelProviderManager instance;private final ViewModelStore viewModelStore = new ViewModelStore();private final ViewModelProvider.Factory factory;private ViewModelProviderManager(Application application) {this.factory = new ViewModelFactory();}public static synchronized ViewModelProviderManager getInstance(Application application) {if (instance == null) {instance = new ViewModelProviderManager(application);}return instance;}@Overridepublic ViewModelStore getViewModelStore() {return viewModelStore;}public ViewModelProvider.Factory getFactory() {return factory;}
}

使用：

创建messageViewModel

   messageViewModel = new ViewModelProvider( ViewModelProviderManager.getInstance(AppProvider.getInstance().getApp()),ViewModelProviderManager.getInstance(AppProvider.getInstance().getApp()).getFactory()).get(MessageViewModel.class);

发送消息

messageViewModel.sendMessage("测试消息");

接收消息

       MessageViewModel messageViewModel = new ViewModelProvider( ViewModelProviderManager.getInstance(AppProvider.getInstance().getApp()),ViewModelProviderManager.getInstance(AppProvider.getInstance().getApp()).getFactory()).get(MessageViewModel.class);messageViewModel.getMessage().observe(this, new Observer<String>() {@Overridepublic void onChanged(String s) {}});

3、LiveDataBus 模式

使用：

发送消息

LiveDataBus.get().with("key_test").setValue("123456");

接收消息

        LiveDataBus.get().with("key_test", String.class).observe(this, new Observer<String>() {@Overridepublic void onChanged(@Nullable String s) {}});

3、EventBus 模式

使用：

注册

EventBus.getDefault().register(this);@Subscribe(threadMode = ThreadMode.POSTING)
public void onLocationMessageEvent(LocationMessageEvent event) {}

发送

EventBus.getDefault().post(new LocationMessageEvent(location));粘性事件
EventBus.getDefault().postSticky(new LocationMessageEvent(location))}