本文實例為大家分享了Android學習之Broadcast的使用方法，供大家參考，具體內容如下
實現開機啟動提示網絡的廣播
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();//創建一個過濾器實例
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);//通過此方法獲取ConnectivityManager實例
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();//調用實例connectivityManager的getActiveNetworkInfo()方法獲取NetworkInfo實例
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();
}
}
}
}
創建BootCompleteReceiver類
右擊com.example.luobo.broadcasttest，New->Other->Broadcast,輸入名字BootCompleteReceiver，勾選Enable，Exported,重寫onReceive()方法。由于使用的是快捷方式創建的類，所需權限會在AndroidManifest.xml中自動注冊。標簽為receiver，但是還不夠修改。
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注冊權限
<?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" />//注冊接收網絡消息廣播
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>//注冊接收開機啟動廣播
<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"/>//開機時系統會發一條此廣播
</intent-filter>
</receiver>
</application>
</manifest>
上述在AndroidMainfest.xml中注冊接收廣播消息屬于靜態注冊，在OnCreate()中注冊的接收廣播屬于動態注冊。
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持億速云。
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