网络是否可用的广播

监听网络状态变化

最新推荐文章于 2024-08-29 20:31:34 发布

原创最新推荐文章于 2024-08-29 20:31:34 发布 · 223 阅读

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本文介绍了一个简单的Android应用程序，用于监听设备的网络连接状态变化，并通过Toast消息通知用户网络是否可用。该应用使用BroadcastReceiver接收系统发出的网络变更广播。

  private IntentFilter intentFilter;
  private NetWorkChangReceiver netWorkChangReceiver;

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

    intentFilter = new IntentFilter();
    intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
    netWorkChangReceiver = new NetWorkChangReceiver();
    //注册广播
    registerReceiver(netWorkChangReceiver, intentFilter);
  }

    @Override
  protected void onDestroy() {
    super.onDestroy();
    //解注册
    unregisterReceiver(netWorkChangReceiver);
  }

  class NetWorkChangReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        //得到ConnectivityManager实例,他是系统的服务类,专门用来管理网络连接的
        ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        //得到networkInfo的实例
        NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
        //调用NetworkInfo的isAvailable()方法判断当前是否有网络
        if (networkInfo != null && networkInfo.isAvailable()) {
            Toast.makeText(MainActivity.this, "network is available", Toast.LENGTH_SHORT).show();
        } else {
            Toast.makeText(MainActivity.this, "network is unavailable", Toast.LENGTH_SHORT).show();
        }
    }
 }
  ps:在功能清单上一定加上权限哦
  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />