从BroadcastReceiver通知活动活动

Question

如果无法使用互联网，我想将TextView显示为当前活动活动。

我正在上网状态但是如何通知当前的活动活动（我的注意力集中在哪个活动中）。

public class NetworkChangeReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(final Context context, final Intent intent) 
    {
        final ConnectivityManager connMgr = (ConnectivityManager) context
            .getSystemService(Context.CONNECTIVITY_SERVICE);

        final android.net.NetworkInfo wifi = connMgr
            .getNetworkInfo(ConnectivityManager.TYPE_WIFI);

        final android.net.NetworkInfo mobile = connMgr
            .getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

        if (wifi.isAvailable() || mobile.isAvailable()) {
            Log.d("TAG", "Netowk Available");
        } else {
            //notify it to current active activity and show a textview as
            //"No internet connection"
        }
    }
}

Answer 1

在您的活动中：

public class YourActivity extends Activity {
    private TextView mTextView;
    public static final String NETWORK_DISABLE_ACTION = "yourpackagename.action.network_disbale";
    private LocalBroadcastManager mLocalBroadcastManager;
    private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            if (intent.getAction().equals(NETWORK_DISABLE_ACTION)) {
                mTextView.setText("No internet connection");
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.your_xml);
        mTextView = (TextView) findViewById(R.id.your_textView_id);
        mLocalBroadcastManager = LocalBroadcastManager.getInstance(this);
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(NETWORK_DISABLE_ACTION);
        mLocalBroadcastManager.registerReceiver(mBroadcastReceiver, intentFilter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        mLocalBroadcastManager.unregisterReceiver(mBroadcastReceiver);
    }        
}

并在您的NetworkChangeReceiver中：

if (wifi.isAvailable() || mobile.isAvailable()) {
        Log.d("TAG", "Netowk Available");
    } else {
        //notify it to current active activity and show a textview as
        //"No internet connection"
        LocalBroadcastManager.getInstance(this).sendBroadcast(new Intent(
            YourActivity.NETWORK_DISABLE_ACTION ));
    }