package com.example.a17broadcast.test6.test617broadcast;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;
// TODO: 2017-06-17
public class MainActivity extends AppCompatActivity {
//过滤器
IntentFilter intentFilter;
//广播
NetworkChangeRecevier networkChangeRecevier;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
intentFilter = new IntentFilter();
//进行过滤,对于网络广播的监听,当网络发生改变,系统给我的提示就是这些。就是说看我们需要监听什么广播
intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
networkChangeRecevier = new NetworkChangeRecevier();
//注册广播
registerReceiver(networkChangeRecevier, intentFilter);
}
@Override
protected void onDestroy() {
super.onDestroy();
//动态注册广播之后需要进行注销广播
unregisterReceiver(networkChangeRecevier);
}
//设置内部类进行网络改变的测试
class NetworkChangeRecevier extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(MainActivity.this, "网络改变", Toast.LENGTH_SHORT).show();
}
}
}
注意可以选择进行网络是否存在判断,只需把内部类中方法进行改变
//设置内部类进行网络改变的测试
class NetworkChangeRecevier extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
//根据系统服务类得到connectactivitymanger,这是一个系统服务类专门用于网络管理
ConnectivityManager connectactivitymanger = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkinfo = connectactivitymanger.getActiveNetworkInfo();
if (networkinfo != null && networkinfo.isAvailable()) {
Toast.makeText(MainActivity.this, "网络存在", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "网络不存在", Toast.LENGTH_SHORT).show();
}
}
}
自然网络权限是必须有呢:
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>