Android学习之Broadcast的简单使用

本文实例为大家分享了Android学习之Broadcast的使用方法，供大家参考，具体内容如下

实现开机启动提示网络的广播

package com.example.luobo.broadcasttest;

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.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

 private IntentFilter intentFilter;
 private NetworkChangeReceiver networkChangeReceiver;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  intentFilter = new IntentFilter();//创建一个过滤器实例
  intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");//添加接收CONNECTIVITY_CHANGE消息
  networkChangeReceiver = new NetworkChangeReceiver();
  registerReceiver(networkChangeReceiver,intentFilter);
 }

 @Override
 protected void onDestroy() {
  super.onDestroy();
  unregisterReceiver(networkChangeReceiver);
 }

 class NetworkChangeReceiver extends BroadcastReceiver{
  @Override
  public void onReceive(Context context, Intent intent) {
   ConnectivityManager connectivityManager = (ConnectivityManager)
     getSystemService(Context.CONNECTIVITY_SERVICE);//通过此方法获取ConnectivityManager实例
   NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();//调用实例connectivityManager的getActiveNetworkInfo()方法获取NetworkInfo实例
   if (networkInfo != null && networkInfo.isAvailable()){
    Toast.makeText(context,"Network is available",Toast.LENGTH_SHORT).show();
   }else {
    Toast.makeText(context,"Network is unavailable",Toast.LENGTH_SHORT).show();
   }
  }
 }
}

创建BootCompleteReceiver类

右击com.example.luobo.broadcasttest，New->Other->Broadcast,输入名字BootCompleteReceiver，勾选Enable，Exported,重写onReceive()方法。由于使用的是快捷方式创建的类，所需权限会在AndroidManifest.xml中自动注册。标签为receiver，但是还不够修改。

package com.example.luobo.broadcasttest;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

public class BootCompleteReceiver extends BroadcastReceiver {

 @Override
 public void onReceive(Context context, Intent intent) {
  Toast.makeText(context,"Boot Complete",Toast.LENGTH_SHORT).show();
 }
}

在AndroidMaifest.xml注册权限

 //注册接收网络消息广播
 //注册接收开机启动广播
 
  
   
    

    
   
  

  
   
    //开机时系统会发一条此广播
   
  
 

上述在AndroidMainfest.xml中注册接收广播消息属于静态注册，在onCreate()中注册的接收广播属于动态注册。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。