EventBus的使用

EventBus主要用于各个组件之间的通信，EventBus作为事件总线方便项目解耦。EventBus整个框架采用订阅者模式来操作。

这里我用两个activity进行通信

这个是第一个activity

public class MainActivity extends AppCompatActivity {    @BindView(R.id.tv_m)    TextView title;    @BindView(R.id.secondActivityBtn)    Button button;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        EventBus.getDefault().register(this);        ButterKnife.bind(this);    }    @OnClick(R.id.tv_m)    public void sayHi(TextView v) {        v.setText("ni hao !");    }    @OnClick(R.id.secondActivityBtn)    public void onClick(View v) {        Intent intent = new Intent(MainActivity.this, SecondActivity.class);        startActivity(intent);    }    //订阅方法，当接收到事件的时候，会调用该方法    @Subscribe(threadMode = ThreadMode.MAIN)    public void onEvent(MessageEvent messageEvent){        Log.d("cylog","receive it");        title.setText(messageEvent.getMessage());        Toast.makeText(MainActivity.this, messageEvent.getMessage(), Toast.LENGTH_SHORT).show();    }    @Override    protected void onDestroy() {        super.onDestroy();        EventBus.getDefault().unregister(this);    }}

对应的xml布局

<?xml version="1.0" encoding="utf-8"?><android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.eventbustest.MainActivity">    <TextView        android:id="@+id/tv_m"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="Hello World!"        app:layout_constraintBottom_toBottomOf="parent"        app:layout_constraintLeft_toLeftOf="parent"        app:layout_constraintRight_toRightOf="parent"        app:layout_constraintTop_toTopOf="parent"        tools:layout_constraintTop_creator="1"        tools:layout_constraintRight_creator="1"        tools:layout_constraintBottom_creator="1"        tools:layout_constraintLeft_creator="1" />    <Button        android:id="@+id/secondActivityBtn"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentBottom="true"        android:layout_centerHorizontal="true"        android:layout_marginTop="117dp"        android:text="点击打开新的Activity"        app:layout_constraintLeft_toLeftOf="parent"        app:layout_constraintRight_toRightOf="parent"        app:layout_constraintTop_toTopOf="parent" /></android.support.constraint.ConstraintLayout>

第二个activity

public class SecondActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_second);        Button button = (Button) findViewById(R.id.sendMessageBtn);        button.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                EventBus.getDefault().post(new MessageEvent("Hello !....."));            }        });    }}

对应xml布局

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:gravity="center">    <Button        android:id="@+id/sendMessageBtn"        android:text="发送消息"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        /></LinearLayout>

还有一个实体类

public class MessageEvent {    private String message;    public MessageEvent(String message){        this.message = message;    }    public String getMessage(){        return message;    }}

model里面的build.gradle里面设置dependencies依赖

compile 'org.greenrobot:eventbus:3.0.0'compile 'com.jakewharton:butterknife:8.5.1'annotationProcessor 'com.jakewharton:butterknife-compiler:8.5.1'

然后运行一下你就可以看到结果了！

官方文档链接：http://greenrobot.org/eventbus/documentation