网上有直接引用support-v4包的，但我用的AndroidX，不能为这个类再引用support-v4
直接自己创建这个类，把androidx.localbroadcastmanager.content.LocalBroadcastManager改改就行。
虽然奇葩但能解决问题

package android.support.v4.content;import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.Uri;
import android.os.Handler;
import android.os.Message;
import android.util.Log;import androidx.annotation.NonNull;import java.util.ArrayList;
import java.util.HashMap;
import java.util.Set;/*** Helper to register for and send broadcasts of Intents to local objects* within your process.  This has a number of advantages over sending* global broadcasts with {@link android.content.Context#sendBroadcast}:* <ul>* <li> You know that the data you are broadcasting won't leave your app, so* don't need to worry about leaking private data.* <li> It is not possible for other applications to send these broadcasts to* your app, so you don't need to worry about having security holes they can* exploit.* <li> It is more efficient than sending a global broadcast through the* system.* </ul>*/
public final class LocalBroadcastManager {private static final class ReceiverRecord {final IntentFilter filter;final BroadcastReceiver receiver;boolean broadcasting;boolean dead;ReceiverRecord(IntentFilter _filter, BroadcastReceiver _receiver) {filter = _filter;receiver = _receiver;}@Overridepublic String toString() {StringBuilder builder = new StringBuilder(128);builder.append("Receiver{");builder.append(receiver);builder.append(" filter=");builder.append(filter);if (dead) {builder.append(" DEAD");}builder.append("}");return builder.toString();}}private static final class BroadcastRecord {final Intent intent;final ArrayList<ReceiverRecord> receivers;BroadcastRecord(Intent _intent, ArrayList<ReceiverRecord> _receivers) {intent = _intent;receivers = _receivers;}}private static final String TAG = "LocalBroadcastManager";private static final boolean DEBUG = false;private final Context mAppContext;private final HashMap<BroadcastReceiver, ArrayList<ReceiverRecord>> mReceivers= new HashMap<>();private final HashMap<String, ArrayList<ReceiverRecord>> mActions = new HashMap<>();private final ArrayList<BroadcastRecord> mPendingBroadcasts = new ArrayList<>();static final int MSG_EXEC_PENDING_BROADCASTS = 1;private final Handler mHandler;private static final Object mLock = new Object();private static android.support.v4.content.LocalBroadcastManager mInstance;@NonNullpublic static android.support.v4.content.LocalBroadcastManager getInstance(@NonNull Context context) {synchronized (mLock) {if (mInstance == null) {mInstance = new android.support.v4.content.LocalBroadcastManager(context.getApplicationContext());}return mInstance;}}private LocalBroadcastManager(Context context) {mAppContext = context;mHandler = new Handler(context.getMainLooper()) {@Overridepublic void handleMessage(Message msg) {switch (msg.what) {case MSG_EXEC_PENDING_BROADCASTS:executePendingBroadcasts();break;default:super.handleMessage(msg);}}};}/*** Register a receive for any local broadcasts that match the given IntentFilter.** @param receiver The BroadcastReceiver to handle the broadcast.* @param filter Selects the Intent broadcasts to be received.** @see #unregisterReceiver*/public void registerReceiver(@NonNull BroadcastReceiver receiver,@NonNull IntentFilter filter) {synchronized (mReceivers) {ReceiverRecord entry = new ReceiverRecord(filter, receiver);ArrayList<ReceiverRecord> filters = mReceivers.get(receiver);if (filters == null) {filters = new ArrayList<>(1);mReceivers.put(receiver, filters);}filters.add(entry);for (int i=0; i<filter.countActions(); i++) {String action = filter.getAction(i);ArrayList<ReceiverRecord> entries = mActions.get(action);if (entries == null) {entries = new ArrayList<ReceiverRecord>(1);mActions.put(action, entries);}entries.add(entry);}}}/*** Unregister a previously registered BroadcastReceiver.  <em>All</em>* filters that have been registered for this BroadcastReceiver will be* removed.** @param receiver The BroadcastReceiver to unregister.** @see #registerReceiver*/public void unregisterReceiver(@NonNull BroadcastReceiver receiver) {synchronized (mReceivers) {final ArrayList<ReceiverRecord> filters = mReceivers.remove(receiver);if (filters == null) {return;}for (int i=filters.size()-1; i>=0; i--) {final ReceiverRecord filter = filters.get(i);filter.dead = true;for (int j=0; j<filter.filter.countActions(); j++) {final String action = filter.filter.getAction(j);final ArrayList<ReceiverRecord> receivers = mActions.get(action);if (receivers != null) {for (int k=receivers.size()-1; k>=0; k--) {final ReceiverRecord rec = receivers.get(k);if (rec.receiver == receiver) {rec.dead = true;receivers.remove(k);}}if (receivers.size() <= 0) {mActions.remove(action);}}}}}}/*** Broadcast the given intent to all interested BroadcastReceivers.  This* call is asynchronous; it returns immediately, and you will continue* executing while the receivers are run.** @param intent The Intent to broadcast; all receivers matching this*     Intent will receive the broadcast.** @see #registerReceiver** @return Returns true if the intent has been scheduled for delivery to one or more* broadcast receivers.  (Note tha delivery may not ultimately take place if one of those* receivers is unregistered before it is dispatched.)*/public boolean sendBroadcast(@NonNull Intent intent) {synchronized (mReceivers) {final String action = intent.getAction();final String type = intent.resolveTypeIfNeeded(mAppContext.getContentResolver());final Uri data = intent.getData();final String scheme = intent.getScheme();final Set<String> categories = intent.getCategories();final boolean debug = DEBUG ||((intent.getFlags() & Intent.FLAG_DEBUG_LOG_RESOLUTION) != 0);if (debug) Log.v(TAG, "Resolving type " + type + " scheme " + scheme+ " of intent " + intent);ArrayList<ReceiverRecord> entries = mActions.get(intent.getAction());if (entries != null) {if (debug) Log.v(TAG, "Action list: " + entries);ArrayList<ReceiverRecord> receivers = null;for (int i=0; i<entries.size(); i++) {ReceiverRecord receiver = entries.get(i);if (debug) Log.v(TAG, "Matching against filter " + receiver.filter);if (receiver.broadcasting) {if (debug) {Log.v(TAG, "  Filter's target already added");}continue;}int match = receiver.filter.match(action, type, scheme, data,categories, "LocalBroadcastManager");if (match >= 0) {if (debug) Log.v(TAG, "  Filter matched!  match=0x" +Integer.toHexString(match));if (receivers == null) {receivers = new ArrayList<ReceiverRecord>();}receivers.add(receiver);receiver.broadcasting = true;} else {if (debug) {String reason;switch (match) {case IntentFilter.NO_MATCH_ACTION: reason = "action"; break;case IntentFilter.NO_MATCH_CATEGORY: reason = "category"; break;case IntentFilter.NO_MATCH_DATA: reason = "data"; break;case IntentFilter.NO_MATCH_TYPE: reason = "type"; break;default: reason = "unknown reason"; break;}Log.v(TAG, "  Filter did not match: " + reason);}}}if (receivers != null) {for (int i=0; i<receivers.size(); i++) {receivers.get(i).broadcasting = false;}mPendingBroadcasts.add(new BroadcastRecord(intent, receivers));if (!mHandler.hasMessages(MSG_EXEC_PENDING_BROADCASTS)) {mHandler.sendEmptyMessage(MSG_EXEC_PENDING_BROADCASTS);}return true;}}}return false;}/*** Like {@link #sendBroadcast(Intent)}, but if there are any receivers for* the Intent this function will block and immediately dispatch them before* returning.*/public void sendBroadcastSync(@NonNull Intent intent) {if (sendBroadcast(intent)) {executePendingBroadcasts();}}@SuppressWarnings("WeakerAccess") /* synthetic access */void executePendingBroadcasts() {while (true) {final BroadcastRecord[] brs;synchronized (mReceivers) {final int N = mPendingBroadcasts.size();if (N <= 0) {return;}brs = new BroadcastRecord[N];mPendingBroadcasts.toArray(brs);mPendingBroadcasts.clear();}for (int i=0; i<brs.length; i++) {final BroadcastRecord br = brs[i];final int nbr = br.receivers.size();for (int j=0; j<nbr; j++) {final ReceiverRecord rec = br.receivers.get(j);if (!rec.dead) {rec.receiver.onReceive(mAppContext, br.intent);}}}}}
}