Android EventBus 基础使用

导入包
implementation 'org.greenrobot:eventbus:3.1.1'
implementation 'com.jakewharton:butterknife:9.0.0-rc2'

public class MainActivity extends AppCompatActivity {

    @BindView(R.id.buton_bu)
    Button butonBu;
    @BindView(R.id.text_tv)
    TextView textTv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        EventBus.getDefault().register(this);

    }
    @OnClick(R.id.buton_bu)
    public void onViewClicked() {
        Intent intent = new Intent();
        intent.setClass(MainActivity.this,SecondActivity.class);
        startActivity(intent);
    }

    @Subscribe(threadMode = ThreadMode.MAIN)
    public void userEventBus(FirstEvent firstEvent) {
        textTv.setText(firstEvent.getName());

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        //注销注册
        EventBus.getDefault().unregister(this);
    }


}

第二界面

public class SecondActivity extends AppCompatActivity {
    @BindView(R.id.edit_et)
    EditText editEt;
    @BindView(R.id.search_bu)
    Button searchBu;
    private String str;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.second_activiy);
        ButterKnife.bind(this);

    }

    @OnClick({ R.id.search_bu})
    public void onViewClicked(View view) {
        switch (view.getId()) {
            case R.id.search_bu:
                str =  editEt.getText().toString();
                EventBus.getDefault().post(new FirstEvent(str));
                finish();
                break;

        }
    }
}

实体类

public class FirstEvent {
    public String name;

    public FirstEvent(String name){
        this.name = name;

    }
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "FirstEvent{" +
                "name='" + name + '\'' +
                '}';
    }




}

MainActivity布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    >

<Button
android:id="@+id/buton_bu"
android:text="点击"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/text_tv"
android:layout_width="match_parent"
android:layout_height="122dp"
android:textSize="18sp"
android:gravity="center"/>

</LinearLayout>

布局SecondActivity
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">


    <EditText
        android:id="@+id/edit_et"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />

    <Button
        android:id="@+id/search_bu"
        android:text="发生数据到主界面"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>