系列一:(159条消息) Android Studio应用基础,手把手教你从入门到精通(小白学习)总结1 之 基础介绍 + intent + 常用控件_好喜欢吃红柚子的博客-CSDN博客
系列二:
(159条消息) Android Studio应用基础,手把手教你从入门到精通(小白学习)总结2 之 常用界面布局和ListView_好喜欢吃红柚子的博客-CSDN博客
八、广播
8.1 Broadcast Receiver 动态广播
实现开关移动数据的时候弹窗提示网络情况发生变化
package cn.edu.sdut.broadcast;
import androidx.appcompat.app.AppCompatActivity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.os.NetworkOnMainThreadException;
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();
// 当网络发生变化时,系统发出的是一个值为"android.net.conn.CONNECTIVITY_CHANGE"的广播,
// 广播接收器想要监听什么广播,就添加相应的action
intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
// 注册,让networkChangeReceiver能监听到intentFilter发出的广播,实现监听网络变化的功能
networkChangeReceiver = new NetworkChangeReceiver();
registerReceiver(networkChangeReceiver,intentFilter);
}
protected void onDestroy(){
super.onDestroy();
// 动态的广播接收器一定要能取消注册,使用unregisterReceiver实现
unregisterReceiver(networkChangeReceiver);
}
// 内部类,重写方法,当网络改变时,会有弹窗提示
class NetworkChangeReceiver extends BroadcastReceiver{
@Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(context, "注意!!!网络发生变化!!!", Toast.LENGTH_SHORT).show();
}
}
}
8.2 静态广播
完成开机后,手机弹窗提示功能
- 新建一个广播类,起名为BootComplleteReceiver
- 在方法中添加弹窗信息
package cn.edu.sdut.broadcast;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;
public class BootComplleteReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
// 弹窗提示信息
Toast.makeText(context, "Boot Complete", Toast.LENGTH_LONG).show();
}
}
- 在配置文件中完成对广播的访问权限的配置
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="cn.edu.sdut.broadcast">
<!-- 加入访问权限 -->
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
<application
android:allowBackup="true"
android:dataExtractionRules="@xml/data_extraction_rules"
android:fullBackupContent="@xml/backup_rules"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/Theme.Broadcast"
tools:targetApi="31">
<!-- 自动完成注册-->
<receiver
android:name=".BootComplleteReceiver"
android:enabled="true"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
<activity
android:name=".MainActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
- 重启手机,有弹窗信息提示