广播接收器也是运行在UI线程,因此,onReceive方法中不能执行太耗时的操作。
否则将因此ANR。一般情况下,根据实际业务需求,
onReceive方法中都会涉及到与其他组件之间的交互,
如发送Notification、启动service等。
当此Activity实例化时,会动态将MyBroadcastReceiver注册到系统中。
当此Activity销毁时,动态注册的MyBroadcastReceiver将不再接收到相应的广播。
根据广播的发送方式,可以将其分为以下几种类型:
1.Normal Broadcast:普通广播
2.System Broadcast: 系统广播
涉及到手机的基本操作,基本上都会发出相应的系统广播。如:开启启动,网络状态改变,
拍照,屏幕关闭与开启,点亮不足等等。每个系统广播都具有特定的intent-filter,
其中主要包括具体的action,系统广播发出后,将被相应的BroadcastReceiver接收。
系统广播在系统内部当特定事件发生时,有系统自动发出。
3.Ordered broadcast:有序广播
定义过程与普通广播无异,
只是其的主要发送方式变为:sendOrderedBroadcast(intent, receiverPermission, ...)。
priority属性值从大到小排序,对于具有相同的priority的动态广播和静态广播,动态广播会排在前面。
4.Sticky Broadcast:粘性广播(在 android 5.0/api 21中deprecated,不再推荐使用,
相应的还有粘性有序广播,同样已经deprecated)
5.Local Broadcast:App应用内广播
常见的增加安全性的方案是:
1.对于同一App内部发送和接收广播,将exported属性人为设置成false,使得非本App内部发出的此广播不被接收;
2.在广播发送和接收时,都增加上相应的permission,用于权限验证;
3.发送广播时,指定特定广播接收器所在的包名,具体是通过intent.setPackage(packageName)指定在,
这样此广播将只会发送到此包中的App内与之相匹配的有效广播接收器中。
//registerReceiver(mBroadcastReceiver, intentFilter);
//注册应用内广播接收器
localBroadcastManager = LocalBroadcastManager.getInstance(this);
localBroadcastManager.registerReceiver(mBroadcastReceiver, intentFilter);
//unregisterReceiver(mBroadcastReceiver);
//取消注册应用内广播接收器
localBroadcastManager.unregisterReceiver(mBroadcastReceiver);
Intent intent = new Intent();
intent.setAction(BROADCAST_ACTION);
intent.putExtra("name", "qqyumidi");
//sendBroadcast(intent);
//发送应用内广播
localBroadcastManager.sendBroadcast(intent);
1.//动态广播 注册和发送
/**
* 定义一个BroadcastReceiver广播接收类:
*/
private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(ACTION_NAME)) {
Toast.makeText(MainActivity.this, "处理action名字相对应的广播", 200);
}
}
};
/**
* 注册广播
*/
public void registerBoradcastReceiver() {
IntentFilter myIntentFilter = new IntentFilter();
myIntentFilter.addAction(ACTION_NAME);
// 注册广播
registerReceiver(mBroadcastReceiver, myIntentFilter);//接收者对象、接受者action
}
1)先调用注册广播
2)发送广播
Intent mIntent = new Intent(ACTION_NAME);
mIntent.putExtra("txt", "发送广播,相当于在这里传送数据");
// 发送广播
sendBroadcast(mIntent);
3)销毁
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
unregisterReceiver(recevier);
}
2.静态注册广播
2.1定义广播类继承 BroadcastReceiver
@Override
public void onReceive(Context context, Intent intent) {
Log.i("TAG", "NormalBroadCastRecevier");
Log.i("TAG", "Action=" + intent.getAction());
}
2.2在manifest中注册 广播action
<receiver android:name="???" >
<intent-filter>
<action android:name="com.jingtai" />
</intent-filter>
</receiver>
2.3发送广播
Log.i("TAG", "静态注册-正在发送正常广播....");
// 封装要启动的广播接收器的action
Intent intent = new Intent("com.jingtai");
sendBroadcast(intent);
3.有序广播 priority
3.1广播的注册方法:通过设置android:priority的数值,控制广播接收的优先级
<receiver android:name="com.??" >
<intent-filter android:priority="80">
<action android:name="com.order" />
</intent-filter>
</receiver>
3.2BroadcastReceiver 中onReceive方法中的参数的传递
封装 bundle参数
Bundle bundle = new Bundle();
bundle.putString("txt", "收到广播之后立马结束广播");
setResultExtras(bundle);
接收 bundle参数
Bundle bundle = this.getResultExtras(true);
Log.i("TAG", "---->values=" + bundle.getString("txt"));
1)创建 多了BroadcastReceiver 对象
2)manifest 注册相同的action 不同的 android:priority= "数值"
3)启动调用 有序广播
// 封装ID
Intent intent = new Intent();
intent.setAction("com.example.ch16_broadcast_ABCD");
// 发送有序广播
sendOrderedBroadcast(intent, null);
============================================
数据传递 有序广播接收者中的数据传递方法;
拦截有序广播 abortBroadcast();
priority 数值越大,优先级越高,即,越先接收到广播
<intent-filter android:priority="1000">
<action android:name="actionName" />
</category></action></intent-filter>
String strMsg = intent.getStringExtra("msg");
Log.e("pzf", "第一个:"+strMsg);
Bundle extras=new Bundle();
extras.putString("msg", "第一个界面传过来的"+strMsg);
setResultExtras(extras); //继续向下川
//abortBroadcast();//开启此处,可以截断广播,不让它传到third中
String strMsg = intent.getStringExtra("msg"); //获取广播的原始数据
Log.e("pzf", "第二个:"+strMsg);
Bundle extras=new Bundle();
extras.putString("msg", "第二个界面传过来的"+strMsg);
setResultExtras(extras); //继续向下
setResultData("第二个:"+strMsg); // "第二个:"+strMsg这是two中新的数据,传递到third中,在third中是用getResultData来获得setResultData("")中的数据
String resultData = getResultData();//获取two中setResultData中的数据
Bundle bundle = getResultExtras(true);//获取two中setResultExtras中的数据
String bundleData = bundle.getString("msg", "");//获取two中setResultExtras()中的数据
String strMsg = intent.getStringExtra("msg");//获取广播的原始数据
Log.e("pzf", "第三个:"+strMsg);
Log.e("pzf", "two中传到third新的数据:"+resultData);
Log.e("pzf", "two中setResultExtras(extras)传到third新的数据:"+bundleData);
==============================================
4.举例演示 Service 和Broadcast 结合刷新UI
4.1主页面注册 广播
private BroadcastReceiver recevier = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
int value = intent.getIntExtra("Key",0);
tv.setText(value + "%");
if (value == 100) {
btnStart.setEnabled(true);
tv.setText("下载完成!");
}
}
};
protected void onDestroy() {
unregisterReceiver(recevier);
};
4.2 注册广播的 IntentFilter
private void initIntentFilter(){
IntentFilter filter = new IntentFilter();
filter.addAction("MyService_send Inner_Broadcast");
this.registerReceiver(recevier, filter);
}
4.3 启动服务类、模拟下载的线程
Intent intent = new Intent(MainActivity.this, MyService.class);
startService(intent);
btnStart.setEnabled(false);//设置按钮不可以点击
4.4 MyService 的实现类 模拟下载耗时操作 发送广播刷新UI
public class MyService extends Service {
@Override
public IBinder onBind(Intent intent) {return null;}
@Override
public void onCreate() {super.onCreate();}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// 模拟耗时操作
new Thread(new Runnable() {
@Override
public void run() {
int count = 0;
Intent i = new Intent();
i.setAction("MyService_send Inner_Broadcast");
while (count < 100) {
count++;
// 模拟多少时间之后才发送广播
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
i.putExtra("Key", count);
// 开始发送广播
sendBroadcast(i);
}
}
}).start();
return super.onStartCommand(intent, flags, startId);
}
}
系统的广播的Action,在离线api可以搜索
Standard Broadcast Actions
These are the current standard actions that Intent defines for
receiving broadcasts (usually through registerReceiver(BroadcastReceiver,
IntentFilter) or a <receiver> tag in a manifest).
ACTION_TIME_TICK
ACTION_TIME_CHANGED
ACTION_TIMEZONE_CHANGED
ACTION_BOOT_COMPLETED
ACTION_PACKAGE_ADDED
ACTION_PACKAGE_CHANGED
ACTION_PACKAGE_REMOVED
ACTION_PACKAGE_RESTARTED
ACTION_PACKAGE_DATA_CLEARED
ACTION_UID_REMOVED
ACTION_BATTERY_CHANGED
ACTION_POWER_CONNECTED
ACTION_POWER_DISCONNECTED
ACTION_SHUTDOWN
具体的demo 下载: http://download.csdn.net/detail/flyingsir_zw/9526557