Question

所以我正在使用firebase构建聊天应用程序。我得到它将消息添加到Firebase数据库。因此消息被推送但我无法在RecyclerView上显示消息历史记录或新发送的消息。我搜索过，大多数答案是使用adapter.startListening（）添加onStart（），使用adapter.stopListening（）添加onStop（）。这对我没有用。任何建议表示赞赏：）

的build.gradle（APP）

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

    //firebase
    implementation 'com.google.firebase:firebase-messaging:12.0.1'
    compile 'com.google.firebase:firebase-core:12.0.1'
    compile 'com.google.firebase:firebase-auth:12.0.1'
    compile 'com.google.firebase:firebase-database:12.0.1'
    compile 'com.firebaseui:firebase-ui-database:3.1.0'
}
apply plugin: 'com.google.gms.google-services'

用于聊天活动的XML

<android.support.v7.widget.RecyclerView
    android:id="@+id/recyclerViewMessages"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentTop="true"
    android:layout_above="@+id/editTextMessage"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"/>

<EditText
    android:id="@+id/editTextMessage"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_toLeftOf="@+id/buttonSend"
    android:layout_toStartOf="@+id/buttonSend"
    android:ems="10"
    android:inputType="textPersonName"
    android:hint="Type Message"
    tools:layout_editor_absoluteX="0dp"
    tools:layout_editor_absoluteY="467dp" />

<Button
    android:id="@+id/buttonSend"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@+id/editTextMessage"
    android:layout_alignParentEnd="true"
    android:layout_alignParentRight="true"
    android:layout_marginEnd="84dp"
    android:layout_marginRight="84dp"
    android:text="Send"
    tools:layout_editor_absoluteX="297dp"
    tools:layout_editor_absoluteY="465dp" />

聊天活动

public class UserChat extends AppCompatActivity {

private RecyclerView recyclerView;
private EditText editTextMessageTyped;
private Button buttonSend;
private FirebaseAuth firebaseAuth;
private FirebaseRecyclerAdapter<Message, ChatHolder> adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_user_chat);

    buttonSend = (Button) findViewById(R.id.buttonSend);

    buttonSend.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            sendMessage();
        }
    });

    Query query = FirebaseDatabase.getInstance().getReference("Chat").child("messageUser");

    FirebaseRecyclerOptions<Message> options = new FirebaseRecyclerOptions.Builder<Message>()
            .setQuery(query, Message.class)
            .setLifecycleOwner(this)
            .build();

    adapter = new FirebaseRecyclerAdapter<Message, ChatHolder>(options) {
        @Override
        public ChatHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_message, parent, false);
            return new ChatHolder(view);
        }

        @Override
        protected void onBindViewHolder(ChatHolder holder, int position, Message model) {

        }
    };

    adapter.notifyDataSetChanged();
    recyclerView = (RecyclerView) findViewById(R.id.recyclerViewMessages);
    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
    linearLayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
    recyclerView.setLayoutManager(linearLayoutManager);
    recyclerView.setAdapter(adapter);
}

@Override
protected void onStart() {
    super.onStart();
    adapter.startListening();
}


@Override
protected void onStop() {
    super.onStop();
    adapter.stopListening();
}


private void sendMessage() {
    editTextMessageTyped = (EditText) findViewById(R.id.editTextMessage);

    // Read the input field and push a new instance of ChatMessage to the Firebase database
    FirebaseDatabase.getInstance().getReference("Chat").push()
            .setValue(new Message(FirebaseAuth.getInstance().getCurrentUser().getEmail(),
                    editTextMessageTyped.getText().toString().trim()));

    // Clear the input editText
    editTextMessageTyped.setText(" ");
}
}

消息模型类

public class Message {

private String MessageUser, MessageBody;
private long timestamp;

public Message(String messageUser, String messageBody) {
    this.MessageUser = messageUser;
    this.MessageBody = messageBody;
    // Initialize to current time
    this.timestamp = new Date().getTime();
}

public Message() {
}

public String getMessageUser() {
    return MessageUser;
}

public String getMessageBody() {
    return MessageBody;
}

public Long getTimestamp() {
    return timestamp;
}
}

聊天持有人类

public class ChatHolder extends RecyclerView.ViewHolder {
private TextView textViewMessageBody, textViewMessageTime;


public ChatHolder(View itemView) {
    super(itemView);
    textViewMessageBody = (TextView) itemView.findViewById(R.id.textViewMessageBody);
    textViewMessageTime = (TextView) itemView.findViewById(R.id.textViewMessageTime);
}

public void blind(Message message) {
    setTextViewMessageBody(message.getMessageBody());
    setTextViewMessageTime("9:40");
}

public void setTextViewMessageBody(String messageBody) {
    textViewMessageBody.setText(messageBody);
}

public void setTextViewMessageTime(String messageTime) {
    textViewMessageTime.setText(messageTime);
}
}

XML item_Message

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">

<TextView
    android:id="@+id/textViewMessageBody"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="MessageBody" />

<TextView
    android:id="@+id/textViewMessageTime"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentEnd="true"
    android:layout_alignParentRight="true"
    android:layout_below="@+id/textViewMessageBody"
    android:text="Time" />
</RelativeLayout>

Firebase JSON

{
  "Chat" : {
    "-LDba09F6-kJeQXC9XIq" : {
      "messageBody" : "cc",
      "messageUser" : "abc2@abc.com",
      "timestamp" : 1527525151377
    },
    "-LDbaS2uc6M8tp4Lbcar" : {
      "messageBody" : "nn",
      "messageUser" : "abc2@abc.com",
      "timestamp" : 1527525265659
    },
    "-LDbaSmSLVF_g3UWLlNh" : {
      "messageBody" : "ee",
      "messageUser" : "abc1@abc.com",
      "timestamp" : 1527525268637
    },
    "-LDbb1xtj7w8ohPfeTgr" : {
      "messageBody" : "oo",
      "messageUser" : "abc2@abc.com",
      "timestamp" : 1527525420926
    },
    "-LDbkI7--YXP_VPpg3fG" : {
      "messageBody" : "jj",
      "messageUser" : "abc2@abc.com",
      "timestamp" : 1527527846402
    }
  }
}

发生了什么的屏幕截图

This is before i click on send

After i click on send

Android FirebaseListAdapter即使在添加侦听器

0 个答案: