EventBus全面讲解和案例

EventBus(https://github.com/greenrobot/EventBus)

EventBus is a publish/subscribe event bus optimized for Android.(EventBus是Android的发布/订阅事件总线优化。)

1.simplifies the communication between components(简化了组件之间的通信)

（1）decouples event senders and receivers(将事件发送者和接受者解耦)

（2）performs well with Activities, Fragments, and background threads(很好的执行活动、碎片和后台线程)

（3）avoids complex and error-prone dependencies and life cycle issues(避免了复杂的和容易出错的依赖性和生命周期问题)

2.makes your code simpler(让你的代码变得更简洁)

3.is fast(很快)

4.is tiny (~50k jar)(很小(jar包只有50k))

5.is proven in practice by apps with 100,000,000+ installs(在实践中超过100,000,000的app安装得到了证明)

6.has advanced features like delivery threads, subscriber priorities, etc.(拥有先进的功能,如交付线程,用户优先级等。)

EventBus in 3 steps(EventBus使用的3个步骤)：

1.Define events:(定义事件)

public static class MessageEvent {

/* Additional fields if needed */ (如果需要额外的字段)

}

2.Prepare subscribers: Declare and annotate your subscribing method, optionally specify a thread mode:(准备订阅者：声明和注释你的订阅方法,选择指定线程模式)

@Subscribe(threadMode = ThreadMode.MAIN)

public void onMessageEvent(MessageEvent event) {/* Do something */};

Register and unregister your subscriber. For example on Android, activities and fragments should usually register according to their life cycle:(注册和注销你的用户。例如在Android上,活动和碎片应该根据其生命周期注册)

@Override

public void onStart() {

super.onStart();

EventBus.getDefault().register(this);

}

@Override

public void onStop() {

super.onStop();

EventBus.getDefault().unregister(this);

}

(官网上面写了两个Activity生命周期中注册和注销，但我的建议是在Oncreate方法中注册，OnDestroy方法中注销)

3.Post events(发布事件)

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

依赖：

Gradle:

compile 'org.greenrobot:eventbus:3.0.0'

简单的使用案例：

package xuechuan.com.myeventbustest;import android.content.Intent;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import android.widget.TextView;import android.widget.Toast;import org.greenrobot.eventbus.EventBus;import org.greenrobot.eventbus.Subscribe;import org.greenrobot.eventbus.ThreadMode;public class MainActivity extends AppCompatActivity implements View.OnClickListener {    private TextView mTv;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //注册EventBus        EventBus.getDefault().register(this);        mTv = (TextView) findViewById(R.id.tv);        Button button = (Button) findViewById(R.id.btn_main);        button.setOnClickListener(this);    }    @Override    public void onClick(View view) {        int id = view.getId();        switch (id)   {            case R.id.btn_main:                Intent intent = new Intent(MainActivity.this,SecondActivity.class);                startActivity(intent);        }    }    @Subscribe(threadMode = ThreadMode.MAIN)    public void onEventMessage(EventMessage event) {        String msg = event.getMsg();        mTv.setText(msg);        Toast.makeText(this,msg,Toast.LENGTH_SHORT).show();    }    @Override    protected void onDestroy() {        super.onDestroy();        //反注册EventBus        EventBus.getDefault().unregister(this);    }}

package xuechuan.com.myeventbustest;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import org.greenrobot.eventbus.EventBus;public class SecondActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_sencond);        Button btnSendEvent = (Button) findViewById(R.id.btn_second);        btnSendEvent.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                //发送消息                EventBus.getDefault().post(new EventMessage("我这边好了，你可以修改UI了"));            }        });    }}

package xuechuan.com.myeventbustest;/** * Created by Administrator on 2017/3/26. */public class EventMessage {    private String mMsg;    public EventMessage(String msg) {            this.mMsg=msg;    }    public String getMsg() {        return mMsg;    }}

更多相关文章

随机推荐