[移动开发]android 实时监控网络改变

第一步：写一个广播接收类

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.widget.Toast;

public class NetworkChangeBroadcast extends BroadcastReceiver {
? ? @Override
? ? public void onReceive(Context context, Intent intent) {
? ? ? ? Log.d("NetworkChangeBroadcast", "network changed!");

? ? ? ? boolean isNetworkAvailable = false, isWifiAvailable = false, isMobileAvailable = false;
? ? ? ? ConnectivityManager connectivityManager = (ConnectivityManager)
? ? ? ? ? ? ? ? context.getSystemService(Context.CONNECTIVITY_SERVICE);
? ? ? ? NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
? ? ? ? if (networkInfo != null) {
? ? ? ? ? ? isNetworkAvailable = networkInfo.isAvailable();
? ? ? ? ? ? isWifiAvailable = networkInfo.isAvailable() && (networkInfo.getType() == ConnectivityManager.TYPE_WIFI);
? ? ? ? ? ? isMobileAvailable = networkInfo.isAvailable() && (networkInfo.getType() == ConnectivityManager.TYPE_MOBILE);
? ? ? ? }

? ? ? ? if (isNetworkAvailable) {
? ? ? ? ? ? if (isWifiAvailable) {
? ? ? ? ? ? ? ? Toast.makeText(context, "当前网络状态：Wifi 可用", Toast.LENGTH_SHORT).show();
? ? ? ? ? ? } else if (isMobileAvailable) {
? ? ? ? ? ? ? ? Toast.makeText(context, "当前网络状态：移动网络可用", Toast.LENGTH_SHORT).show();
? ? ? ? ? ? }
? ? ? ? } else {
? ? ? ? ? ? Toast.makeText(context, "当前网络状态：网络不可用", Toast.LENGTH_SHORT).show();
? ? ? ? }
? ? }
}

第二步：在需要监控的类中引用，一般为activity的基类，动态注册广播监听网络的变化，在onCreate中注册，onDestroy中反注册

import android.content.IntentFilter;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class BaseActivity extends AppCompatActivity {

? ? private NetworkChangeBroadcast networkChangeBroadcast = null;

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

? ? ? ? networkChangeBroadcast = new NetworkChangeBroadcast();
? ? ? ? IntentFilter intentFilter = new IntentFilter();
? ? ? ? intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
? ? ? ? registerReceiver(networkChangeBroadcast, intentFilter);
? ? }

? ? @Override
? ? protected void onDestroy() {
? ? ? ? super.onDestroy();
? ? ? ? unregisterReceiver(networkChangeBroadcast);
? ? }
}

最后注意:访问网络状态需要在Manifest中添加网络访问权限? ? ? ? ?android.permission.ACCESS_NETWORK_STATE