关于EventBus的使用

最新推荐文章于 2025-09-11 22:10:09 发布

转载最新推荐文章于 2025-09-11 22:10:09 发布 · 72 阅读

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原文链接：https://my.oschina.net/u/1539097/blog/520765

文章标签：

#python #ui

本文详细介绍了如何在Android应用中使用EventBus进行事件传递，包括消息类的定义、Activity中的注册与注销、消息的发送与接收，以及不同线程环境下事件处理的策略。同时提供了关键jar包的下载链接。

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使用步骤：

①：自己写个消息类（需要什么属性就添加什么字段）

eg:

public class MessageEvent {

public final String message;

public MessageEvent(String message) {

this.message = message;

}

②：在activity中注册和注销EventBus

EventBus.getDefault().register(this);

EventBus.getDefault().unregister(this);

③：在需要发送数据即消息的地方调用以下方法，发送你的消息类对象

EventBus.getDefault().post(new MessageEvent("fffffffffff"));

④：在需要接收数据即消息的地方，声明并实现“订阅函数”

@Subscribe ------------这个注解是订阅者的标记，不可省略

/**
   * MainThread: Subscriber will be called in Android's main thread (sometimes
   * referred to as UI thread). If the posting thread is the main thread,
   * event handler methods will be called directly. Event handlers using this
   * mode must return quickly to avoid blocking the main thread.
   *
   * @param messageEvent
   */
   @Subscribe
   public void onEventMainThread(MessageEvent messageEvent) {
       String msg = "onEventMainThread收到了消息：" + messageEvent.message;
       Log.d("harvic", msg);
       Toast.makeText(this, msg, Toast.LENGTH_LONG).show();
   }

   /**
   * BackgroundThread: Subscriber will be called in a background thread. If
   * posting thread is not the main thread, event handler methods will be
   * called directly in the posting thread. If the posting thread is the main
   * thread, EventBus uses a single background thread that will deliver all
   * its events sequentially. Event handlers using this mode should try to
   * return quickly to avoid blocking the background thread
   *
   * @param event
   */
   @Subscribe
   public void onEventBackgroundThread(MessageEvent event) {
       Log.d("harvic", "onEventBackground收到了消息：" + event.message);
   }

   /**
   * Async: Event handler methods are called in a separate thread. This is
   * always independent from the posting thread and the main thread. Posting
   * events never wait for event handler methods using this mode. Event
   * handler methods should use this mode if their execution might take some
   * time, e.g. for network access. Avoid triggering a large number of long
   * running asynchronous handler methods at the same time to limit the number
   * of concurrent threads. EventBus uses a thread pool to efficiently reuse
   * threads from completed asynchronous event handler notifications
   *
   * @param event
   */
   @Subscribe
   public void onEventAsync(MessageEvent event) {
       Log.d("harvic", "onEventAsync收到了消息：" + event.message);
   }

   /**
   * PostThread: Subscriber will be called in the same thread, which is
   * posting the event. This is the default. Event delivery implies the least
   * overhead because it avoids thread switching completely. Thus this is the
   * recommended mode for simple tasks that are known to complete is a very
   * short time without requiring the main thread. Event handlers using this
   * mode should return quickly to avoid blocking the posting thread, which
   * may be the main thread. Example:
   *
   * @param messageEvent
   */
   @Subscribe
   public void onEvent(MessageEvent event) {
       Log.d("harvic", "OnEvent收到了消息：" + event.message);
   }