Android：检测网络状态&监听网络变化

1. 检测网络状态

1.1 实现思路

1. 获得ConnectivityManager对象

ConnectivityManager主要用于查看网络状态和管理网络连接相关的操作

2. 获取ConnectivityManager对象对应的NetworkInfo对象

NetworkInfo对象包含网络连接的所有信息

3. 根据需要从NetworkInfo对象取出关于网络连接的信息

1.2 特别注意

由于在API23及以上时，getNetworkInfo(int networkType)方法已被弃用，取而代之的是：

getAllNetworks();
getNetworkInfo(android.net.Network);
getNetworkInfo(Network network);

步骤1：自定义广播接收器

NetWorkStateReceiver.java

public class NetWorkStateReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        System.out.println("网络状态发生变化");
        //检测API是不是小于23，因为到了API23之后getNetworkInfo(int networkType)方法被弃用
        if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.LOLLIPOP) {
            //获得ConnectivityManager对象
            ConnectivityManager connMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            //获取ConnectivityManager对象对应的NetworkInfo对象
            // 获取WIFI连接的信息
            NetworkInfo wifiNetworkInfo = connMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
            //获取移动数据连接的信息
            NetworkInfo dataNetworkInfo = connMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
            if (wifiNetworkInfo.isConnected() && dataNetworkInfo.isConnected()) {
                Toast.makeText(context, "WIFI已连接,移动数据已连接", Toast.LENGTH_SHORT).show();
            } else if (wifiNetworkInfo.isConnected() && !dataNetworkInfo.isConnected()) {
                Toast.makeText(context, "WIFI已连接,移动数据已断开", Toast.LENGTH_SHORT).show();
            } else if (!wifiNetworkInfo.isConnected() && dataNetworkInfo.isConnected()) {
                Toast.makeText(context, "WIFI已断开,移动数据已连接", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(context, "请检查网络", Toast.LENGTH_SHORT).show();
            }
        } else {
            System.out.println("API level 大于23");
            //获得ConnectivityManager对象
            ConnectivityManager connMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            //获取所有网络连接的信息
            Network[] networks = connMgr.getAllNetworks();
            //用于存放网络连接信息
            StringBuilder sb = new StringBuilder();
            //通过循环将网络信息逐个取出来
            for (int i = 0; i < networks.length; i++) {
                //获取ConnectivityManager对象对应的NetworkInfo对象
                NetworkInfo networkInfo = connMgr.getNetworkInfo(networks[i]);
                sb.append(networkInfo.getTypeName() + " connect is " + networkInfo.isConnected());
            }
            Toast.makeText(context, sb.toString(), Toast.LENGTH_SHORT).show();
        }
    }

}

动态注册

MainActivity.java

public class MainActivity extends AppCompatActivity {
    NetWorkStateReceiver netWorkStateReceiver;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    //在onResume()方法注册
    @Override
    protected void onResume() {
        if (netWorkStateReceiver == null) {
            netWorkStateReceiver = new NetWorkStateReceiver();
        }
        IntentFilter filter = new IntentFilter();
        filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
        registerReceiver(netWorkStateReceiver, filter);
        System.out.println("注册");
        super.onResume();
    }

    //onPause()方法注销
    @Override
    protected void onPause() {
        unregisterReceiver(netWorkStateReceiver);
        System.out.println("注销");
        super.onPause();
    }
}

步骤3：添加网络权限

AndroidManifest.xml




作者：Carson_Ho
链接：https://www.jianshu.com/p/983889116526
來源：简书