【发布时间】:2017-06-13 10:46:18
【问题描述】:
我想在广播接收器的每个活动中不断检查互联网连接。我已经编写了代码并且它运行良好。但我想在每一项活动中都使用它。如何修改此代码?
public class MainActivity extends Activity {
private static final String LOG_TAG = "CheckNetworkStatus";
private NetworkChangeReceiver receiver;
private boolean isConnected = false;
private TextView networkStatus;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
IntentFilter filter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
receiver = new NetworkChangeReceiver();
registerReceiver(receiver, filter);
networkStatus = (TextView) findViewById(R.id.networkStatus);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
@Override
protected void onDestroy() {
Log.v(LOG_TAG, "onDestory");
super.onDestroy();
unregisterReceiver(receiver);
}
public class NetworkChangeReceiver extends BroadcastReceiver {
@Override
public void onReceive(final Context context, final Intent intent) {
Log.v(LOG_TAG, "Receieved notification about network status");
isNetworkAvailable(context);
}
private boolean isNetworkAvailable(Context context) {
ConnectivityManager connectivity = (ConnectivityManager)
context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivity != null) {
NetworkInfo[] info = connectivity.getAllNetworkInfo();
if (info != null) {
for (int i = 0; i < info.length; i++) {
if (info[i].getState() == NetworkInfo.State.CONNECTED) {
if(!isConnected){
Log.v(LOG_TAG, "Now you are connected to Internet!");
networkStatus.setText("Now you are connected to Internet!");
isConnected = true;
//do your processing here ---
//if you need to post any data to the server or get status
//update from the server
}
return true;
}
}
}
}
Log.v(LOG_TAG, "You are not connected to Internet!");
networkStatus.setText("You are not connected to Internet!");
isConnected = false;
return false;
}
}
}
【问题讨论】:
-
“持续”是什么意思?
-
像 Facebook,它同时检查互联网连接。当我断开 wifi/移动设备时,它会在小吃栏中显示一条消息(“断开连接”)类似的东西。
-
这不会经常检查。当某些事情发生变化并做出响应时,它会收到一个事件。
标签: android android-activity android-broadcastreceiver