子事件侦听器继续将自身添加到recyclerView中 [英] Child Event Listener Keep adding itself in recyclerView
本文介绍了子事件侦听器继续将自身添加到recyclerView中的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在尝试在recyclerview中显示两个用户之间的消息.一切正常，直到我在重新启动活动时都在两个设备中的任何一个上重新启动活动时，都添加了一个子事件侦听器，并且我看到多条消息代替了我发送的事件，并且当我重新启动活动而未发送任何消息时，它向我显示原始数量的消息，如果我再次发送或接收消息，我会看到多条消息，并且循环重复.我曾尝试在onDestroy和onStop中删除侦听器，但没有用.
I am trying to show messages between two users in a recyclerview . Everything goes alright until i restart the activity in either device of the both when i restart the activity a child event listener is added and i see multiple message in place of one that i sent and when i restart my activity without sending any message it shows me original number of messages and if i send or recieve a message again i see multiple messages and the cycle repeats.I have tried removing listener in onDestroy and onStop but no use.
代码
MessageActivity.java(已更新)
MessageActivity.java(updated)
public class MessageActivity extends AppCompatActivity {
CircleImageView profile_image;
TextView user_name;
FirebaseFirestore fstore;
FirebaseAuth fAuth;
FirebaseUser fuser;
DatabaseReference reference;
ChildEventListener mChildEventListener;
ValueEventListener mValueEventListener;
Toolbar toolbar;
ImageButton imageButton;
EditText textsend;
String userID;
MessageAdapter messageAdapter;
List<Chat> mChat;
RecyclerView recyclerView;
DatabaseReference Chatreference;
String TAG = "MyTag";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_message);
fAuth = FirebaseAuth.getInstance();
fstore = FirebaseFirestore.getInstance();
userID = fAuth.getCurrentUser().getUid();
profile_image = findViewById(R.id.profile_image);
user_name = findViewById(R.id.username);
imageButton = findViewById(R.id.btn_send);
textsend = findViewById(R.id.text_send);
recyclerView = findViewById(R.id.recycler_view2);
recyclerView.setHasFixedSize(true);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getApplicationContext());
linearLayoutManager.setStackFromEnd(true);
recyclerView.setLayoutManager(linearLayoutManager);
toolbar = findViewById(R.id.myToolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle("");
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
finish();
}
});
Intent intent = getIntent();
fuser = FirebaseAuth.getInstance().getCurrentUser();
String userid = intent.getStringExtra("userid");
//String username = intent.getStringExtra("UserName");
reference = FirebaseDatabase.getInstance().getReference("Users").child(userid);
mValueEventListener = new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
User user = dataSnapshot.getValue(User.class);
user_name.setText(user.getFirst());
Log.d(TAG, "Value Event Listener called");
if (user.getImageURL().equals("default")) {
profile_image.setImageResource(R.mipmap.ic_launcher);
} else {
//and this
Glide.with(getApplicationContext()).load(user.getImageURL()).into(profile_image);
}
readMessages(fuser.getUid(), userid, user.getImageURL());
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
};
reference.addValueEventListener(mValueEventListener);
imageButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String msg = textsend.getText().toString();
textsend.setText("");
if (!msg.equals("")) {
sendMessage(fuser.getUid(), userid, msg);
} else {
Toast.makeText(MessageActivity.this, "Empty messages cant be send", Toast.LENGTH_SHORT).show();
}
}
});
}
private void sendMessage(String sender, final String receiver, String message) {
HashMap<String, Object> hashMap = new HashMap<>();
hashMap.put("sender", sender);
hashMap.put("receiver", receiver);
hashMap.put("message", message);
DatabaseReference Chatreference = FirebaseDatabase.getInstance().getReference("Chats");
String key = Chatreference.push().getKey();
Chatreference.child(key).setValue(hashMap);
}
private void readMessages(String myid, String userid, String imageurl) {
mChat = new ArrayList<>();
Chatreference = FirebaseDatabase.getInstance().getReference("Chats");
mChildEventListener = new ChildEventListener() {
@Override
public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
Chat chat = dataSnapshot.getValue(Chat.class);
if (chat.getReceiver().equals(myid) && chat.getSender().equals(userid) ||
chat.getReceiver().equals(userid) && chat.getSender().equals(myid)) {
chat.setMessageId(dataSnapshot.getKey());
mChat.add(chat);
Log.d(TAG, "Child_Event_Listener_Called");
Log.d(TAG, "msg " + chat.getMessage());
}
Log.d(TAG, "msg " + chat.getMessage());
messageAdapter = new MessageAdapter(MessageActivity.this, mChat, imageurl);
recyclerView.setAdapter(messageAdapter);
messageAdapter.notifyDataSetChanged();
}
@Override
public void onChildChanged(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
}
@Override
public void onChildRemoved(@NonNull DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
Chat chat = dataSnapshot.getValue(Chat.class);
chat.setMessageId(dataSnapshot.getKey());
mChat.remove(chat);
messageAdapter.notifyDataSetChanged();
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
};
Chatreference.addChildEventListener(mChildEventListener);
}
@Override
protected void onDestroy() {
super.onDestroy();
Chatreference.removeEventListener(mChildEventListener);
}
}
MessageAdapter.java
MessageAdapter.java
public class MessageAdapter extends RecyclerView.Adapter<MessageAdapter.ViewHolder> {
public static final int MSG_TYPE_LEFT = 0;
public static final int MSG_TYPE_RIGHT = 1;
private Context mContext;
private List<Chat> mChat;
String imageurl;
FirebaseUser fuser;
public MessageAdapter(Context mContext, List<Chat> mChat,String imageurl) {
this.mContext = mContext;
this.mChat = mChat;
this.imageurl=imageurl;
}
@NonNull
@Override
public MessageAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
if (viewType == MSG_TYPE_RIGHT) {
View view = LayoutInflater.from(mContext).inflate(R.layout.chat_item_right, parent, false);
return new MessageAdapter.ViewHolder(view);
}
else {
View view = LayoutInflater.from(mContext).inflate(R.layout.chat_item_left, parent, false);
return new MessageAdapter.ViewHolder(view);
}
}
@Override
public void onBindViewHolder(@NonNull MessageAdapter.ViewHolder holder, int position) {
Chat chat=mChat.get(position);
holder.show_message.setText(chat.getMessage());
if (imageurl.equals("default")){
holder.profile_image.setImageResource(R.mipmap.ic_launcher);
} else {
Glide.with(mContext).load(imageurl).into(holder.profile_image);
}
holder.show_message.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
String message_id=chat.getMessageId();
Task<Void> task = Utils.removeUser(message_id);
task.addOnSuccessListener(new OnSuccessListener<Void>() {
@Override
public void onSuccess(Void aVoid) {
Toast.makeText(mContext,"Message Deleted",Toast.LENGTH_SHORT).show();
}
});
return true;
}
});
}
@Override
public int getItemCount() {
return mChat.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
public TextView show_message;
public ImageView profile_image;
public ViewHolder(@NonNull View itemView) {
super(itemView);
show_message=itemView.findViewById(R.id.show_message);
profile_image=itemView.findViewById(R.id.profile_image);
}
}
@Override
public int getItemViewType(int position) {
fuser= FirebaseAuth.getInstance().getCurrentUser();
if (mChat.get(position).getSender().equals(fuser.getUid())){
return MSG_TYPE_RIGHT;
}
else {
return MSG_TYPE_LEFT;
}
}
}
Chat.java
Chat.java
public class Chat {
private String sender;
private String receiver;
private String message;
String MessageId;
public Chat(String sender, String receiver, String message) {
this.sender = sender;
this.receiver = receiver;
this.message = message;
}
public Chat() {
}
public String getSender() {
return sender;
}
public void setSender(String sender) {
this.sender = sender;
}
public String getReceiver() {
return receiver;
}
public void setReceiver(String receiver) {
this.receiver = receiver;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
public String getMessageId() {
return MessageId;
}
public void setMessageId(String messageId) {
MessageId = messageId;
}
@Override
public boolean equals(@Nullable Object obj) {
if(obj instanceof Chat){
Chat chat=(Chat) obj;
return this.MessageId.equals(chat.getMessageId());}
else
return false;
}
}
推荐答案
首先，您可以使用addListenerForSingleValueEvent()方法简化这种情况:
Firstly you you can use the addListenerForSingleValueEvent() method to simplify this scenario:
reference.addValueEventListener(mValueEventListener);
其他建议
reference = FirebaseDatabase.getInstance().getReference("Chats").child("RoomId");
我认为这更好.您无需听其他聊天
I think it is better. You don't need to listen to other chats
这篇关于子事件侦听器继续将自身添加到recyclerView中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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