阅读下面关于广播的代码,请补全代码,实现当网络断开时,发送广播的功能。(每空 2 分,共 10 分) package com.example.networkchangedbroadcast; import androidx.appcompat.app.AppCompatActivity; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.os.Bundle; import android.view.View; import android.widget.Toast; public class MainActivity extends AppCompatActivity { private ChangeReceiver changeReceiver test ; private IntentFilter intentFilter ; @Override protected void onCreate(Bundle savedInstanceState) { (第一空 2 分) .onCreate(savedInstanceState); setContentView(R.layout. activity_main ); intentFilter = new IntentFilter(); intentFilter . (第二空 2 分 ) ( "android.net.conn.CONNECTIVITY_CHANGE" ); changeReceiver test = new (第三空 2 分 ) (第四空 2 分 ) } @Override public void onDestroy() { super .onDestroy(); unregisterReceiver( changeReceiver test ); } class ChangeReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { (第五空 2 分 ) NetworkInfo networkInfo=connectivityManager.getActiveNetworkInfo(); if (networkInfo!= null &&networkInfo.isAvailable()){ Toast toast=Toast. makeText (context, " 网络已连接 " ,Toast. LENGTH_LONG ); View view=toast.getView(); view.setBackgroundResource(R.drawable. shapes ); toast.setView(view); toast.show(); } else { Toast toast=Toast. makeText (context, " 网络已断开 " ,Toast. LENGTH_LONG ); View view=toast.getView(); view.setBackgroundResource(R.drawable. shapes ); toast.setView(view); toast.show(); } } } }