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

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.luobo.broadcasttest">

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />//注册接收网络消息广播
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>//注册接收开机启动广播
<application
 android:allowBackup="true"
 android:icon="@mipmap/ic_launcher"
 android:label="@string/app_name"
 android:roundIcon="@mipmap/ic_launcher_round"
 android:supportsRtl="true"
 android:theme="@style/AppTheme">
 <activity android:name=".MainActivity">
  <intent-filter>
   <action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
  </intent-filter>
 </activity>

<receiver
  android:name=".BootCompleteReceiver"
  android:enabled="true"
  android:exported="true">
  <intent-filter>
   <action android:name="android.intent.action.BOOT_COMPLETED"/>//开机时系统会发一条此广播
  </intent-filter>
 </receiver>
</application>

</manifest>

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。