Android安卓开发 网络状态监听

package com.czh.networkchangereceiver;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity {
//    private netChange netChange;
//    private IntentFilter netChangeIF;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
//        netChangeIF = new IntentFilter();
//        netChangeIF.addAction("android.net.conn.CONNECTIVITY_CHANGE");
//        netChange = new netChange();
//        registerReceiver(netChange, netChangeIF);
    }


//
//    class netChange extends BroadcastReceiver {
//
//        @Override
//        public void onReceive(Context context, Intent intent) {
//            ConnectivityManager c = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
//            NetworkInfo info = c.getActiveNetworkInfo();
//            if (info != null && info.isAvailable()) {
//                Toast.makeText(context, "net error ", Toast.LENGTH_SHORT).show();
//            }else {
//                Toast.makeText(context, "network is unavailable",
//                        Toast.LENGTH_SHORT).show();
//            }
//        }
//    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}