当用户尝试向上或向下滚动视图时，会出现滚动问题。看起来循环不能正常工作，但我没有发现代码的哪一部分可能是这种行为的原因。
如需视觉表示，请查看截图。
2）After scrolling
这是我的回收视图适配器：
public class ChatRecyclerAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{
private static final int VIEW_TYPE_ME=1;
private static final int VIEW_TYPE_OTHER=2;
private List<Chat>myChat;
public ChatRecyclerAdapter(List<Chat> myChat) {
this.myChat = myChat;
}
public void add(Chat chat){
myChat.add(chat);
notifyItemInserted(myChat.size()-1);
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater layoutInflater=LayoutInflater.from(parent.getContext());
RecyclerView.ViewHolder viewHolder=null;
switch (viewType){
case VIEW_TYPE_ME:
View viewChatMine=layoutInflater.inflate(R.layout.item_chat_mine,parent,false);
viewHolder=new MyChatViewHolder(viewChatMine);
break;
case VIEW_TYPE_OTHER:
View viewChatOther=layoutInflater.inflate(R.layout.item_chat_other,parent,false);
viewHolder=new OtherChatViewHolder(viewChatOther);
break;
}
return viewHolder;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if(TextUtils.equals(myChat.get(position).senderUid, FirebaseAuth.getInstance().getCurrentUser().getUid())){
configureMyChatViewHolder((MyChatViewHolder)holder,position);
}else{
configureOtherChatViewHolder((OtherChatViewHolder)holder,position);
}
}
public void configureMyChatViewHolder(MyChatViewHolder myChatViewHolder,int position){
Chat chat=myChat.get(position);
myChatViewHolder.txtChatMessage.setText(chat.message);
}
public void configureOtherChatViewHolder(OtherChatViewHolder otherChatViewHolder,int position){
Chat chat=myChat.get(position);
otherChatViewHolder.txtChatMessage.setText(chat.message);
}
@Override
public int getItemViewType(int position) {
if(TextUtils.equals(myChat.get(position).senderUid,FirebaseAuth.getInstance().getCurrentUser().getUid())){
return VIEW_TYPE_ME;
}else{
return VIEW_TYPE_OTHER;
}
}
@Override
public int getItemCount() {
if(myChat!=null){
return myChat.size();
}
return 0;
}
private static class MyChatViewHolder extends RecyclerView.ViewHolder{
private TextView txtChatMessage;
public MyChatViewHolder(View itemView){
super(itemView);
txtChatMessage=(TextView)itemView.findViewById(R.id.chatMineTextView);
}
}
private static class OtherChatViewHolder extends RecyclerView.ViewHolder{
private TextView txtChatMessage;
public OtherChatViewHolder(View itemView){
super(itemView);
txtChatMessage=(TextView) itemView.findViewById(R.id.chatOtherTextView);
}
}
}
聊天活动片段：
package com.example.ayselkas.myapplication.Fragments;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.widget.RecyclerView;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import com.example.ayselkas.myapplication.Activity.ChatActivity;
import com.example.ayselkas.myapplication.Adapters.ChatRecyclerAdapter;
import com.example.ayselkas.myapplication.LocalStorage.Constants;
import com.example.ayselkas.myapplication.Models.Chat;
import com.example.ayselkas.myapplication.R;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import org.greenrobot.eventbus.EventBus;
import java.util.ArrayList;
import static com.google.android.gms.internal.zzs.TAG;
/**
* A placeholder fragment containing a simple view.
*/
public class ChatActivityFragment extends Fragment {
private RecyclerView myRecyclerViewChat;
private EditText myTxtMessage;
private ProgressDialog myProgressDialog; // progress bar can be used instead
private ChatRecyclerAdapter myChatRecyclerAdapter;
private Button sendButton;
private Chat chat;
///////////
///////////
public static ChatActivityFragment newInstance(String receiver,
String receiverUid,
String firebaseToken) {
Bundle args = new Bundle();
args.putString(Constants.ARG_RECEIVER, receiver);
args.putString(Constants.ARG_RECEIVER_UID, receiverUid);
args.putString(Constants.ARG_FIREBASE_TOKEN, firebaseToken);
ChatActivityFragment fragment = new ChatActivityFragment();
fragment.setArguments(args);
return fragment;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View fragmentView = inflater.inflate(R.layout.fragment_chat, container, false);
sendButton=(Button) fragmentView.findViewById(R.id.sendMessageButton);
sendButton.setEnabled(false);
sendButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
sendMessage();
}
});
bindViews(fragmentView);
return fragmentView;
}
private void bindViews(View view) {
myRecyclerViewChat = (RecyclerView) view.findViewById(R.id.chatRecyclerView);
myTxtMessage = (EditText) view.findViewById(R.id.typeText);
myTxtMessage.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
if(charSequence.toString().trim().length() > 0) {
sendButton.setEnabled(true);}
}
@Override
public void afterTextChanged(Editable editable) {
}
});
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
init();
}
private void init() {
myProgressDialog = new ProgressDialog(getActivity());
myProgressDialog.setTitle("LOading");
myProgressDialog.setMessage("Please Wait");
myProgressDialog.setIndeterminate(true);
getMessageFromFirebaseUser(FirebaseAuth.getInstance().getCurrentUser().getUid(),
getActivity().getIntent().getExtras().getString(Constants.ARG_RECEIVER_UID));
// mChatPresenter.getMessage(FirebaseAuth.getInstance().getCurrentUser().getUid(),
// getArguments().getString(Constants.ARG_RECEIVER_UID));
}
private void sendMessage() {
String message = myTxtMessage.getText().toString();
String receiver = getActivity().getIntent().getExtras().getString(Constants.ARG_RECEIVER);
String receiverUid = getActivity().getIntent().getExtras().getString(Constants.ARG_RECEIVER_UID);
String sender = FirebaseAuth.getInstance().getCurrentUser().getEmail();
String senderUid = FirebaseAuth.getInstance().getCurrentUser().getUid();
Chat chat = new Chat(sender,
receiver,
senderUid,
receiverUid,
message,
System.currentTimeMillis());
sendMessageToFirebaseUser(chat);
}
public void sendMessageToFirebaseUser( final Chat chat) {
final String room_type_1 = chat.senderUid + "_" + chat.receiverUid;
final String room_type_2 = chat.receiverUid + "_" + chat.senderUid;
final DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference();
databaseReference.child(Constants.ARG_CHAT_ROOMS).getRef().addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.hasChild(room_type_1)) {
Log.e(TAG, "sendMessageToFirebaseUser: " + room_type_1 + " exists");
databaseReference.child(Constants.ARG_CHAT_ROOMS).child(room_type_1).child(String.valueOf(chat.timestamp)).setValue(chat);
} else if (dataSnapshot.hasChild(room_type_2)) {
Log.e(TAG, "sendMessageToFirebaseUser: " + room_type_2 + " exists");
databaseReference.child(Constants.ARG_CHAT_ROOMS).child(room_type_2).child(String.valueOf(chat.timestamp)).setValue(chat);
} else {
Log.e(TAG, "sendMessageToFirebaseUser: success");
databaseReference.child(Constants.ARG_CHAT_ROOMS).child(room_type_1).child(String.valueOf(chat.timestamp)).setValue(chat);
getMessageFromFirebaseUser(chat.senderUid, chat.receiverUid);
}
// send push notification to the receiver
// sendPushNotificationToReceiver(chat.sender,
// chat.message,
// chat.senderUid,
// new SharedPrefUtil(context).getString(Constants.ARG_FIREBASE_TOKEN),
// receiverFirebaseToken);
onSendMessageSuccess();
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
public void getMessageFromFirebaseUser(String senderUid, String receiverUid) {
final String room_type_1 = senderUid + "_" + receiverUid;
final String room_type_2 = receiverUid + "_" + senderUid;
final DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference();
databaseReference.child(Constants.ARG_CHAT_ROOMS).getRef()
.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(dataSnapshot.hasChild(room_type_1)) {
FirebaseDatabase.getInstance()
.getReference()
.child(Constants.ARG_CHAT_ROOMS)
.child(room_type_1).addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Chat chat = dataSnapshot.getValue(Chat.class);
onGetMessageSuccess(chat);
}
@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}else if(dataSnapshot.hasChild(room_type_2)) {
FirebaseDatabase.getInstance().getReference().child(Constants.ARG_CHAT_ROOMS)
.child(room_type_2).addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Chat chat =dataSnapshot.getValue((Chat.class));
}
@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}else{
Log.e(TAG,"getMessageFromFirebaseUser: no such room available");
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
public void onGetMessageSuccess(Chat chat){
if(myChatRecyclerAdapter==null||myChatRecyclerAdapter.getItemCount()==0){
myChatRecyclerAdapter=new ChatRecyclerAdapter(new ArrayList<Chat>());
myRecyclerViewChat.setAdapter(myChatRecyclerAdapter);
}
myChatRecyclerAdapter.add(chat);
myRecyclerViewChat.smoothScrollToPosition(myChatRecyclerAdapter.getItemCount()-1);
}
public void onSendMessageSuccess(){
myTxtMessage.setText("");
}
}
最后聊聊XML代码：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/fragment_chat"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.ayselkas.myapplication.Fragments.ChatActivityFragment"
tools:showIn="@layout/activity_chat">
<android.support.v7.widget.RecyclerView
android:id="@+id/chatRecyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@+id/typeText"
app:layoutManager="LinearLayoutManager"/>
<EditText
android:id="@+id/typeText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:background="@drawable/send_box"
android:ems="10"
android:layout_margin="8dp"
android:hint="Type a message..."
android:imeOptions="actionSend"
android:inputType="text"
android:padding="8dp" />
<Button
android:id="@+id/sendMessageButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:text="send" />
</RelativeLayout>
答案 0 :(得分：0)
活动片段声明中的问题是 。我在activity.xml和片段事务中做了声明，这就是我遇到这种动画问题的原因。