Unit5：广播

静态广播

1.定义

public class TestBroadCast extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        Toast.makeText(context, "静态注册", Toast.LENGTH_SHORT).show();
    }
}

2.注册

 <receiver
            android:name=".TestBroadCast"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED"/>
            </intent-filter>
        </receiver>

3.发送

 Intent intent = new Intent();
 intent.setAction("HELLO");
 intent.addFlags(0x01000000);    // Android 8.0之后的变化，需要添加之后，静态才能发送广播
 sendBroadcast(intent);

动态广播（有序广播）

1.定义

//        定义接收器
         broadcastReceiver = new BroadcastReceiver() {

            @Override
            public void onReceive(Context context, Intent intent) {
                Toast.makeText(context, "动态注册", Toast.LENGTH_SHORT).show();
            }
        };

2.注册

//        注册
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("HELLO");
        registerReceiver(broadcastReceiver, intentFilter);

3.发送

        Intent intent = new Intent();
        intent.setAction("HELLO");
        sendOrderedBroadcast(intent,null);       // 有序广播的发送

本地广播

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final LocalBroadcastManager localBroadcastManager = LocalBroadcastManager.getInstance(this);   // 开启本地广播管理
        Button button = findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent("TEST");
                localBroadcastManager.sendBroadcast(intent);
            }
        });

        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("TEST");
        BroadcastReceiver receiver = new BroadcastReceiver() {

            @Override
            public void onReceive(Context context, Intent intent) {
                Toast.makeText(context, "received", Toast.LENGTH_SHORT).show();
            }
        };

        localBroadcastManager.registerReceiver(receiver,intentFilter);