广播：一、本地广播

广播类型：

• 全局：其它APP可以收到（可以说是;public）
• 本地：只有自己APP收到（可以说是：private）

广播机制：

• 无序：接收端不可修改，不可拦截
• 有序：接收端：可修改，可拦截

---

一、本地广播：

广播定义：

在这里你可以留意一下：

　　当我使用单例实现的时候，传递拖来的创建方，我并不直接用。

　　因为：它是谁？生命周期怎么样？是个问题。

　　所以我采用 getApplicationContext 。来进行和App周期进行绑定。（详情可多去了解一下关于Context。）

public class Broadcaster {
    private static Broadcaster sInstance;
    private Context mContext;

    private LocalBroadcastManager localBroadcastManager;

    public static Broadcaster getInstance(Context context, BroadcastReceiver receiver) {
        if (sInstance == null) {
            sInstance = new Broadcaster(context.getApplicationContext(),receiver);
        }
        return sInstance;
    }

    private Broadcaster(Context context, BroadcastReceiver receiver) {
        mContext = context;
        setReceiver(receiver);
    }

    public void setReceiver(BroadcastReceiver receiver) {

        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("com.bug01.Broadcast.AAA");
        intentFilter.addAction("com.bug01.Broadcast.BBB");

        //注册本地接收器
        localBroadcastManager = LocalBroadcastManager.getInstance(mContext);
        localBroadcastManager.registerReceiver(receiver, intentFilter);
    }

    public void DoSomething() {
        // 定义一个线程，模拟从其它地方发生了一个广告。
        new Thread(new Runnable() {
            @Override
            public void run() {
                Intent intent = new Intent("com.bug01.Broadcast.AAA");
                //发送本地广播
                localBroadcastManager.sendBroadcast(intent);//发送无序广播
                //localBroadcastManager.sendBroadcastSync(intent);//发送有序广播
            }
        }).start();
    }

    /**
     * 注销时要同时注销接收器
     */
    protected void onDestroy(BroadcastReceiver receiver) {
        localBroadcastManager.unregisterReceiver(receiver);
    }
}

接收器定义：

public class LocalReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        Toast.makeText(context, "收到本地广播" + intent.getAction(), Toast.LENGTH_SHORT).show();
        //abortBroadcast(); 取消广播向下传递
    }
}

使用：

public class MainActivity extends AppCompatActivity {

    Broadcaster mBroadcaster;
    LocalReceiver mLocalReceiver;

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

        mLocalReceiver = new LocalReceiver();

        mBroadcaster =  Broadcaster.getInstance(this, mLocalReceiver);
        mBroadcaster.DoSomething();
    }


    @Override
    protected void onDestroy() {
        mBroadcaster.onDestroy(mLocalReceiver);
        super.onDestroy();
    }
}