Android开发之动态注册监听网络变化

来源：互联网发布：斗罗大陆进阶数据编辑：程序博客网时间：2024/05/03 09:22

直接上代码，下面代码实现提醒有无网络

package com.example.broadcasttest;

import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.view.Menu;
import android.widget.Toast;

public class MainActivity extends Activity {

   private IntentFilter intentFilter;
   private NetworkChangeReceiver networkChangeReceiver;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        intentFilter=new IntentFilter();
        intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
        networkChangeReceiver=new NetworkChangeReceiver();
        registerReceiver(networkChangeReceiver,intentFilter);
    }



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

}

这里有一点需要说明，安卓系统为了安全性，程序要访问关键性信息，必须要在配置文件中声明权限，否则程序会崩溃，或者无法获取相应的信息

在AndroidManifest.xml中添加

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

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