Answers:
如果您考虑以下线程，则我不确定该API是否直接提供API ：
我想知道同样的事情。
就我而言，我有一个BroadcastReceiver实现，Context#unregisterReceiver(BroadcastReceiver)在处理它收到的Intent之后，调用 将自身作为参数传递。
接收者的onReceive(Context, Intent)方法被多次调用的可能性很小，因为它已向多个对象注册IntentFilters，从而有可能IllegalArgumentException被抛出Context#unregisterReceiver(BroadcastReceiver)。就我而言，我可以存储一个私有的同步成员，以便在调用之前进行检查
Context#unregisterReceiver(BroadcastReceiver)，但是如果API提供了check方法，它将更加干净。
没有API函数可以检查接收者是否已注册。解决方法是将您的代码放在一个try catch block as done below.
try {
//Register or UnRegister your broadcast receiver here
} catch(IllegalArgumentException e) {
e.printStackTrace();
}public class MyReceiver extends BroadcastReceiver {
public boolean isRegistered;
/**
* register receiver
* @param context - Context
* @param filter - Intent Filter
* @return see Context.registerReceiver(BroadcastReceiver,IntentFilter)
*/
public Intent register(Context context, IntentFilter filter) {
try {
// ceph3us note:
// here I propose to create
// a isRegistered(Contex) method
// as you can register receiver on different context
// so you need to match against the same one :)
// example by storing a list of weak references
// see LoadedApk.class - receiver dispatcher
// its and ArrayMap there for example
return !isRegistered
? context.registerReceiver(this, filter)
: null;
} finally {
isRegistered = true;
}
}
/**
* unregister received
* @param context - context
* @return true if was registered else false
*/
public boolean unregister(Context context) {
// additional work match on context before unregister
// eg store weak ref in register then compare in unregister
// if match same instance
return isRegistered
&& unregisterInternal(context);
}
private boolean unregisterInternal(Context context) {
context.unregisterReceiver(this);
isRegistered = false;
return true;
}
// rest implementation here
// or make this an abstract class as template :)
...
}MyReceiver myReceiver = new MyReceiver();
myReceiver.register(Context, IntentFilter); // register
myReceiver.unregister(Context); // unregister 广告1
-回复：
这确实不是那么优雅，因为您必须记住在注册后设置isRegistered标志。–隐身犹太教教士
-在接收器中增加了“更加优雅的方式”来注册和设置标志
如果您重新启动设备或您的应用被操作系统杀死，则此操作将无效。– amin 6小时前
@amin-查看已注册接收者的代码中的生命周期（不是清单条目所注册的系统）：）
我正在使用此解决方案
public class ReceiverManager {
private static List<BroadcastReceiver> receivers = new ArrayList<BroadcastReceiver>();
private static ReceiverManager ref;
private Context context;
private ReceiverManager(Context context){
this.context = context;
}
public static synchronized ReceiverManager init(Context context) {
if (ref == null) ref = new ReceiverManager(context);
return ref;
}
public Intent registerReceiver(BroadcastReceiver receiver, IntentFilter intentFilter){
receivers.add(receiver);
Intent intent = context.registerReceiver(receiver, intentFilter);
Log.i(getClass().getSimpleName(), "registered receiver: "+receiver+" with filter: "+intentFilter);
Log.i(getClass().getSimpleName(), "receiver Intent: "+intent);
return intent;
}
public boolean isReceiverRegistered(BroadcastReceiver receiver){
boolean registered = receivers.contains(receiver);
Log.i(getClass().getSimpleName(), "is receiver "+receiver+" registered? "+registered);
return registered;
}
public void unregisterReceiver(BroadcastReceiver receiver){
if (isReceiverRegistered(receiver)){
receivers.remove(receiver);
context.unregisterReceiver(receiver);
Log.i(getClass().getSimpleName(), "unregistered receiver: "+receiver);
}
}
}您有几种选择
您可以在班级或活动中添加标记。将一个布尔变量放入您的类中，然后查看此标志以了解您是否已注册Receiver。
创建一个扩展Receiver的类，您可以在其中使用：
单例模式在您的项目中仅具有此类的一个实例。
实现用于知道接收方是否已注册的方法。
您必须使用try / catch：
try {
if (receiver!=null) {
Activity.this.unregisterReceiver(receiver);
}
} catch (IllegalArgumentException e) {
e.printStackTrace();
}您可以轻松完成...。
1）创建一个布尔变量...
private boolean bolBroacastRegistred;2）注册广播接收器时，将其设置为TRUE
...
bolBroacastRegistred = true;
this.registerReceiver(mReceiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));
....3）在onPause（）中执行...
if (bolBroacastRegistred) {
this.unregisterReceiver(mReceiver);
bolBroacastRegistred = false
}就这样，现在，您将不会在onPause（）上收到更多异常错误消息。
提示1：始终在onPause（）中使用unregisterReceiver（）而不是在onDestroy（）中使用提示2：运行unregisterReceive（）时，不要忘记将bolBroadcastRegistred变量设置为FALSE
成功！
我使用Intent来让Broadcast Receiver知道Main Activity线程的Handler实例，并使用Message将消息传递给Main Activity
我已经使用这种机制来检查广播接收器是否已经注册。有时，当您动态注册广播接收器并且不想进行两次注册时，或者在广播接收器正在运行时向用户展示时，需要使用它。
主要活动：
public class Example extends Activity {
private BroadCastReceiver_example br_exemple;
final Messenger mMessenger = new Messenger(new IncomingHandler());
private boolean running = false;
static class IncomingHandler extends Handler {
@Override
public void handleMessage(Message msg) {
running = false;
switch (msg.what) {
case BroadCastReceiver_example.ALIVE:
running = true;
....
break;
default:
super.handleMessage(msg);
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
IntentFilter filter = new IntentFilter();
filter.addAction("pl.example.CHECK_RECEIVER");
br_exemple = new BroadCastReceiver_example();
getApplicationContext().registerReceiver(br_exemple , filter); //register the Receiver
}
// call it whenever you want to check if Broadcast Receiver is running.
private void check_broadcastRunning() {
/**
* checkBroadcastHandler - the handler will start runnable which will check if Broadcast Receiver is running
*/
Handler checkBroadcastHandler = null;
/**
* checkBroadcastRunnable - the runnable which will check if Broadcast Receiver is running
*/
Runnable checkBroadcastRunnable = null;
Intent checkBroadCastState = new Intent();
checkBroadCastState .setAction("pl.example.CHECK_RECEIVER");
checkBroadCastState .putExtra("mainView", mMessenger);
this.sendBroadcast(checkBroadCastState );
Log.d(TAG,"check if broadcast is running");
checkBroadcastHandler = new Handler();
checkBroadcastRunnable = new Runnable(){
public void run(){
if (running == true) {
Log.d(TAG,"broadcast is running");
}
else {
Log.d(TAG,"broadcast is not running");
}
}
};
checkBroadcastHandler.postDelayed(checkBroadcastRunnable,100);
return;
}
.............
}广播接收器：
public class BroadCastReceiver_example extends BroadcastReceiver {
public static final int ALIVE = 1;
@Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
Bundle extras = intent.getExtras();
String action = intent.getAction();
if (action.equals("pl.example.CHECK_RECEIVER")) {
Log.d(TAG, "Received broadcast live checker");
Messenger mainAppMessanger = (Messenger) extras.get("mainView");
try {
mainAppMessanger.send(Message.obtain(null, ALIVE));
} catch (RemoteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
.........
}
}我个人使用调用unregisterReceiver并吞下异常的方法。我同意这很丑陋，但目前提供了最好的方法。
我提出了一个功能请求，以获取一个布尔方法来检查是否已将接收者注册添加到Android API中。如果您想添加它，请在这里支持：https : //code.google.com/p/android/issues/detail?id=73718
我遇到了您的问题，我在应用程序中遇到了同样的问题。我在应用程序中多次调用了registerReceiver（）。
解决此问题的简单方法是在“自定义应用程序类”中调用registerReceiver（）。这将确保您的广播接收器在整个应用程序生命周期中仅被调用。
public class YourApplication extends Application
{
@Override
public void onCreate()
{
super.onCreate();
//register your Broadcast receiver here
IntentFilter intentFilter = new IntentFilter("MANUAL_BROADCAST_RECIEVER");
registerReceiver(new BroadcastReciever(), intentFilter);
}
}这就是我的方法，它是ceph3us给出的答案的修改版本，并由slinden77编辑（除其他外，我删除了不需要的方法的返回值）：
public class MyBroadcastReceiver extends BroadcastReceiver{
private boolean isRegistered;
public void register(final Context context) {
if (!isRegistered){
Log.d(this.toString(), " going to register this broadcast receiver");
context.registerReceiver(this, new IntentFilter("MY_ACTION"));
isRegistered = true;
}
}
public void unregister(final Context context) {
if (isRegistered) {
Log.d(this.toString(), " going to unregister this broadcast receiver");
context.unregisterReceiver(this);
isRegistered = false;
}
}
@Override
public void onReceive(final Context context, final Intent intent) {
switch (getResultCode()){
//DO STUFF
}
}
}然后在一个Activity类上：
public class MyFragmentActivity extends SingleFragmentActivity{
MyBroadcastReceiver myBroadcastReceiver;
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
registerBroacastReceiver();
}
@Override
protected Fragment createFragment(){
return new MyFragment();
}
//This method is called by the fragment which is started by this activity,
//when the Fragment is done, we also register the receiver here (if required)
@Override
public void receiveDataFromFragment(MyData data) {
registerBroacastReceiver();
//Do some stuff
}
@Override
protected void onStop(){
unregisterBroacastReceiver();
super.onStop();
}
void registerBroacastReceiver(){
if (myBroadcastReceiver == null)
myBroadcastReceiver = new MyBroadcastReceiver();
myBroadcastReceiver.register(this.getApplicationContext());
}
void unregisterReceiver(){
if (MyBroadcastReceiver != null)
myBroadcastReceiver.unregister(this.getApplicationContext());
}
}我把这段代码放在我的父母活动中
列出已注册的接收者=新的ArrayList <>（）;
@Override
public Intent registerReceiver(BroadcastReceiver receiver, IntentFilter filter) {
registeredReceivers.add(System.identityHashCode(receiver));
return super.registerReceiver(receiver, filter);
}
@Override
public void unregisterReceiver(BroadcastReceiver receiver) {
if(registeredReceivers.contains(System.identityHashCode(receiver)))
super.unregisterReceiver(receiver);
}对我来说，以下工作：
if (receiver.isOrderedBroadcast()) {
requireContext().unregisterReceiver(receiver);
}这是我检查广播者是否已经注册的方法，即使您关闭了应用程序（finish（））
Firstime运行您的应用程序，首先发送广播，它将返回true / false，这取决于您的广播公司是否仍在运行。
我的广播员
public class NotificationReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
if(intent.getExtras() != null && intent.getStringExtra("test") != null){
Log.d("onReceive","test");
return;
}
}
}我的主要活动
// init Broadcaster
private NotificationReceiver nr = new NotificationReceiver();
Intent msgrcv = new Intent("Msg");
msgrcv.putExtra("test", "testing");
boolean isRegistered = LocalBroadcastManager.getInstance(this).sendBroadcast(msgrcv);
if(!isRegistered){
Toast.makeText(this,"Starting Notification Receiver...",Toast.LENGTH_LONG).show();
LocalBroadcastManager.getInstance(this).registerReceiver(nr,new IntentFilter("Msg"));
}if( receiver.isOrderedBroadcast() ){
// receiver object is registered
}
else{
// receiver object is not registered
}只需检查NullPointerException。如果接收者不存在，则...
try{
Intent i = new Intent();
i.setAction("ir.sss.smsREC");
context.sendBroadcast(i);
Log.i("...","broadcast sent");
}
catch (NullPointerException e)
{
e.getMessage();
}