EventBus 事件学习和学习

 1.对于粘滞事件，产生后一直存在，可以反复接收，EventBus.getDefault().registerSticky会触发接收之前已经产生的粘滞事件，并且执行事件函数
若EventBus.getDefault().registerSticky执行时并没有可以接收的粘滞事件，不会执行事件函数的哦

2.onEventMainThread(SecondEvent event) {

注意这里的的参数类型决定了EventBus.getDefault().post出来的事件是否会通知这个事件函数（当时就执行哦）

package com.example.administrator.studyeventbus01;import android.app.Activity;import android.content.Intent;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.Button;import android.widget.TextView;import android.widget.Toast;import de.greenrobot.event.EventBus;/** * 我向MainActivity里面注册事件可以理解为向EventBus表示我是事件的观察者 * 我向MainActivity里面反注册事件可以理解为向EeentBus表示我不再是事件的观察者 */public class MainActivity extends Activity {    Button btn;    TextView tv;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //注册EventBus     //  EventBus.getDefault().register(this);        EventBus.getDefault().registerSticky(this);        btn = (Button) findViewById(R.id.btn_try);        tv = (TextView)findViewById(R.id.tv);        btn.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent = new Intent(getApplicationContext(), SecondActivity.class);                startActivity(intent);            }        });    }    @Override    protected void onDestroy(){        super.onDestroy();        EventBus.getDefault().unregister(this);//反注册EventBus    }    public void onEvent(SecondEvent event) {        String msg = "onEventMainThread收到了消息：" + event.getMsg();        Log.d("harvic", msg);        tv.setText(msg);        Toast.makeText(this, msg, Toast.LENGTH_LONG).show();    }    /**     * onEventMainThread是本我这个事件观察者接受事件消息并且只在UI线程执行的     *     * 通过EventBus.getDefault().post(new FirstEvent("FirstEvent btn clicked"));方法调用之后     * 可以及时调用到onEventMainThread，不需要等等回到这个页面才调用哦     * 参考地址:http://blog.csdn.net/harvic880925/article/details/40660137     * @param event     */   public void onEventMainThread(SecondEvent event) {        String msg = "onEventMainThread收到了消息：" + event.getMsg();        Log.d("harvic", msg);        tv.setText(msg);        Toast.makeText(this, msg, Toast.LENGTH_LONG).show();    } /*    public void onEventBackground(FirstEvent event) {        String msg = "onEventMainThread收到了消息：" + event.getMsg();        Log.d("harvic", msg);        tv.setText(msg);        Toast.makeText(this, msg, Toast.LENGTH_LONG).show();    }    public void onEventAsync(FirstEvent event) {        String msg = "onEventMainThread收到了消息：" + event.getMsg();        Log.d("harvic", msg);        tv.setText(msg);        Toast.makeText(this, msg, Toast.LENGTH_LONG).show();    }*/}

package com.example.administrator.studyeventbus01;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.widget.Button;import de.greenrobot.event.EventBus;public class SecondActivity extends Activity {    private Button btn_FirstEvent;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_second);        btn_FirstEvent = (Button) findViewById(R.id.btn_first_event);        btn_FirstEvent.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                //     EventBus.getDefault().post(new FirstEvent("FirstEvent btn clicked"));             EventBus.getDefault().postSticky(new FirstEvent("FirstEvent btn clicked"));            }        });        btn_FirstEvent.setOnLongClickListener(new View.OnLongClickListener() {            @Override            public boolean onLongClick(View v) {                Intent intent = new Intent(getApplicationContext(), ThirdActivity.class);                startActivity(intent);                return false;            }        });    }}

package com.example.administrator.studyeventbus01;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.TextView;import android.widget.Toast;import de.greenrobot.event.EventBus;/** * 我向MainActivity里面注册事件可以理解为向EventBus表示我是事件的观察者 * 我向MainActivity里面反注册事件可以理解为向EeentBus表示我不再是事件的观察者 */public class ThirdActivity extends Activity {    Button btn;    TextView tv;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //注册EventBus     //  EventBus.getDefault().register(this);  //      EventBus.getDefault().registerSticky(this);<strong><span style="color:#FF0000;">//这个位置不行，这里执行后直接执行那个事件方法时，控件还没有初始化呢</span></strong>        btn = (Button) findViewById(R.id.btn_try);        tv = (TextView)findViewById(R.id.tv);        btn.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent = new Intent(getApplicationContext(), SecondActivity.class);                startActivity(intent);            }        });        EventBus.getDefault().registerSticky(this);  /<strong><span style="color:#FF0000;">/现在的位置是合适的，粘滞事件可以反复接收到，但是如果执行这句话的时候没有事件通知，则不执行事件函数</span></strong>    }    @Override    protected void onDestroy(){        super.onDestroy();        EventBus.getDefault().unregister(this);//反注册EventBus    } /*   public void onEvent(FirstEvent event) {        String msg = "onEventMainThread收到了消息11：" + event.getMsg();        Log.d("harvic", msg);        tv.setText(msg);        btn.setText(msg);        Toast.makeText(this, msg, Toast.LENGTH_LONG).show();    }*/   public void onEventMainThread(FirstEvent event) {        String msg = "onEventMainThread收到了消息111：" + event.getMsg();        Log.d("harvic", msg);       String aa = btn.getText().toString();       btn.setText("123456");        Toast.makeText(this, msg, Toast.LENGTH_LONG).show();    } /*    public void onEventBackground(FirstEvent event) {        String msg = "onEventMainThread收到了消息：" + event.getMsg();        Log.d("harvic", msg);        tv.setText(msg);        Toast.makeText(this, msg, Toast.LENGTH_LONG).show();    }    public void onEventAsync(FirstEvent event) {        String msg = "onEventMainThread收到了消息：" + event.getMsg();        Log.d("harvic", msg);        tv.setText(msg);        Toast.makeText(this, msg, Toast.LENGTH_LONG).show();    }*/}

参考：http://blog.csdn.net/harvic880925/article/details/40787203（分上下两篇博客）