Android 監控網絡狀態

1. public static boolean isNetworkAvailable(Context context) {
2. ConnectivityManager connectivity = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
3. if (connectivity == null) {
4. Log.i("NetWorkState", "Unavailabel");
5. return false;
6. } else {
7. NetworkInfo[] info = connectivity.getAllNetworkInfo();
8. if (info != null) {
9. for (int i = 0; i < info.length; i++) {
10. if (info[i].getState() == NetworkInfo.State.CONNECTED) {
11. Log.i("NetWorkState", "Availabel");
12. return true;
13. }
14. }
15. }
16. }
17. return false;
18. }

上面這個方法就是判斷網絡是否連接的代碼，返回true表示有網絡，返回false表示無網絡。 在Android網絡應用程序開發中，經常要判斷網絡連接是否可用，因此經常有必要監聽網絡狀態的變化。android的網絡狀態監聽可以用BroadcastReceiver來接收網絡狀態改變的廣播，具體實現如下：

1. @Override
2. public void onReceive(Context context, Intent intent) {
3. Log.e(TAG, "網絡狀態改變");
5. boolean success = false;
7. //獲得網絡連接服務
8. ConnectivityManager connManager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
9. // State state = connManager.getActiveNetworkInfo().getState();
10. State state = connManager.getNetworkInfo(
11. ConnectivityManager.TYPE_WIFI).getState(); // 獲取網絡連接狀態
12. if (State.CONNECTED == state) { // 判斷是否正在使用WIFI網絡
13. success = true;
14. }
16. state = connManager.getNetworkInfo(
17. ConnectivityManager.TYPE_MOBILE).getState(); // 獲取網絡連接狀態
18. if (State.CONNECTED != state) { // 判斷是否正在使用GPRS網絡
19. success = true;
20. }
22. if (!success) {
23. Toast.makeText(LocationMapActivity.this, "您的網絡連接已中斷", Toast.LENGTH_LONG).show();
24. }
26. }

1. //注冊網絡監聽
2. IntentFilter filter = new IntentFilter();
3. filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
4. registerReceiver(mNetworkStateReceiver, filter);
5. //在Activity中的onDestroy中:'
7. unregisterReceiver(mNetworkStateReceiver); //取消監聽