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  • 本地广播

    一、概念

      系统广播可以被其他任何的应用程序接收到,同时也可以接受到其他任何应用程序发出的广播,存在一定的安全性问题。

      本地广播只能在应用程序内部传递,广播接收器也只能接受来自本应用程序发出的广播。

    二、本地广播用法

      本地广播使用LocalBroadcastManager进行管理。本地广播无法通过静态注册的方式来接受。

      public class MainActivity extends Activity {
        private IntentFilter intentFilter;
        private LocalReceiver localReceiver;
        private LocalBroadcastManager localBroadcastManager;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          localBroadcastManager = LocalBroadcastManager.getInstance(this);
          // 获取实例
          Button button = (Button) findViewById(R.id.button);
          button.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
              Intent intent = new Intent("com.example.broadcasttest.LOCAL_BROADCAST");
              localBroadcastManager.sendBroadcast(intent); // 发送本地广播
            }
          });
          intentFilter = new IntentFilter();
          intentFilter.addAction("com.example.broadcasttest.LOCAL_BROADCAST");
          localReceiver = new LocalReceiver();
          localBroadcastManager.registerReceiver(localReceiver, intentFilter);
          // 注册本地广播监听器
          }
          @Override
          protected void onDestroy() {
          super.onDestroy();

          localBroadcastManager.unregisterReceiver(localReceiver);
        }
        class LocalReceiver extends BroadcastReceiver {
        @Override
          public void onReceive(Context context, Intent intent) {
            Toast.makeText(context, "received local broadcast",
            Toast.LENGTH_SHORT).show();
          }
        }
      }

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  • 原文地址:https://www.cnblogs.com/llxbl/p/6186884.html
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