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。

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。