Android LocalBroadCastManager简介

LocalBroadCastManager也是广播的一种，但不同的是BroadCastReceiver用于不同进程间通信，总体来说适用于安全性要求不太高的数据传递，而LocalBroadCastManager适用于应用内部的信息传递，又称之为局部通知管理器。

LocalBroadCastManager在android-support-v4.jar（这个相信大家都不陌生）中引入，有效率高，安全性高，可代替Thread与Handle组合刷新UI等优点。

示例代码：
public class MainActivity extends Activity {

    /**
     *  定义三个Action状态
     */
    static final String ACTION_STARTED = "com.example.android.supportv4.STARTED";
    static final String ACTION_UPDATE = "com.example.android.supportv4.UPDATE";
    static final String ACTION_STOPPED = "com.example.android.supportv4.STOPPED";

    LocalBroadcastManager mBroadCastManager;
    BroadcastReceiver mBroadCastReceiver;
    TextView mTextView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        init();
    }

    private void init(){
        mTextView = (TextView) this.findViewById(R.id.showText);
        mBroadCastManager = LocalBroadcastManager.getInstance(this);

        IntentFilter filter = new IntentFilter();
        filter.addAction(ACTION_STARTED);
        filter.addAction(ACTION_UPDATE);
        filter.addAction(ACTION_STOPPED);

        mBroadCastReceiver = new BroadcastReceiver() {

            @Override
            public void onReceive(Context context, Intent intent) {
                if(intent.getAction().equals(ACTION_STARTED)){

                    mTextView.setText("Start !");

                } else if(intent.getAction().equals(ACTION_UPDATE)){

                    mTextView.setText(intent.getExtras().get("update").toString());

                } else if(intent.getAction().equals(ACTION_STOPPED)){

                    mTextView.setText("Stoppppp !");

                }

            }
        };

        /**
         * 注册LocalBroadCastManager
         */
        mBroadCastManager.registerReceiver(mBroadCastReceiver,filter);


        /**
         * 开启线程传递数据
         */
        new Thread(new Runnable() {
            @Override
            public void run() {

                Intent myIntent = new Intent(ACTION_UPDATE);
                myIntent.putExtra("update","LaLaLa");

                mBroadCastManager.sendBroadcast(myIntent);
            }
        }).start();
    }

    @Override
    protected void onStop() {
        super.onStop();
        /**
         * 取消LocalBroadCastManager
         */
        mBroadCastManager.unregisterReceiver(mBroadCastReceiver);
    }
}