Question

我正在尝试使用ArrayList和Recyclerview.Adapter获取所有用户聊天（在我的数据库中创建），但我的模拟器屏幕上只显示了ArrayList中的第一项

以下是相应的代码：

MainActivity ：

package com.wipro.chat.activity;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.v4.content.LocalBroadcastManager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;

import com.android.volley.NetworkResponse;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GoogleApiAvailability;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;

import com.wipro.chat.R;
import com.wipro.chat.adapter.ChatRoomsAdapter;
import com.wipro.chat.app.Config;
import com.wipro.chat.app.EndPoints;
import com.wipro.chat.app.MyApplication;
import com.wipro.chat.gcm.GcmIntentService;
import com.wipro.chat.gcm.NotificationUtils;
import com.wipro.chat.helper.SimpleDividerItemDecoration;
import com.wipro.chat.model.ChatRoom;
import com.wipro.chat.model.Message;

public class MainActivity extends AppCompatActivity {

    private String TAG = MainActivity.class.getSimpleName();
    private static final int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;
    private BroadcastReceiver mRegistrationBroadcastReceiver;
    private ArrayList<ChatRoom> chatRoomArrayList;
    private ChatRoomsAdapter mAdapter;
    private RecyclerView recyclerView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        /**
         * Check for login session. If not logged in launch
         * login activity
         * */
        if (MyApplication.getInstance().getPrefManager().getUser() == null) {
            launchLoginActivity();
        }

        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);

        /**
         * Broadcast receiver calls in two scenarios
         * 1. gcm registration is completed
         * 2. when new push notification is received
         * */
        mRegistrationBroadcastReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {

                // checking for type intent filter
                if (intent.getAction().equals(Config.REGISTRATION_COMPLETE)) {
                    // gcm successfully registered
                    // now subscribe to `global` topic to receive app wide notifications
                    subscribeToGlobalTopic();

                } else if (intent.getAction().equals(Config.SENT_TOKEN_TO_SERVER)) {
                    // gcm registration id is stored in our server's MySQL
                    Log.e(TAG, "GCM registration id is sent to our server");

                } else if (intent.getAction().equals(Config.PUSH_NOTIFICATION)) {
                    // new push notification is received
                    handlePushNotification(intent);
                }
            }
        };

        chatRoomArrayList = new ArrayList<>();
        mAdapter = new ChatRoomsAdapter(this, chatRoomArrayList);
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
        recyclerView.addItemDecoration(new SimpleDividerItemDecoration(
                getApplicationContext()
        ));
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setAdapter(mAdapter);

        recyclerView.addOnItemTouchListener(new ChatRoomsAdapter.RecyclerTouchListener(getApplicationContext(), recyclerView, new ChatRoomsAdapter.ClickListener() {
            @Override
            public void onClick(View view, int position) {
                // when chat is clicked, launch full chat thread activity
                ChatRoom userChatRoom = chatRoomArrayList.get(position);
                Intent intent = new Intent(MainActivity.this, ChatRoomActivity.class);
                intent.putExtra("user_id", userChatRoom.getId());
                intent.putExtra("name", userChatRoom.getName());
                startActivity(intent);
            }

            @Override
            public void onLongClick(View view, int position) {

            }
        }));

        /**
         * Always check for google play services availability before
         * proceeding further with GCM
         * */
        if (checkPlayServices()) {
            registerGCM();
            fetchChatRooms();
        }
    }

    /**
     * Handles new push notification
     */
    private void handlePushNotification(Intent intent) {
        /*int type = intent.getIntExtra("type", -1);

        // if the push is of chat room message
        // simply update the UI unread messages count
        if (type == Config.PUSH_TYPE_CHATROOM) {
            Message message = (Message) intent.getSerializableExtra("message");
            String chatRoomId = intent.getStringExtra("chat_room_id");

            if (message != null && chatRoomId != null) {
                updateRow(chatRoomId, message);
            }
        } else if (type == Config.PUSH_TYPE_USER) {
            // push belongs to user alone
            // just showing the message in a toast
            Message message = (Message) intent.getSerializableExtra("message");
            Toast.makeText(getApplicationContext(), "New push: " + message.getMessage(), Toast.LENGTH_LONG).show();
        }*/
        Message message = (Message) intent.getSerializableExtra("message");
        String userChatRoomId = intent.getStringExtra("user_id");

        if (message != null && userChatRoomId != null) {
            updateRow(userChatRoomId, message);
        }


    }

    /**
     * Updates the chat list unread count and the last message
     */
    private void updateRow(String chatRoomId, Message message) {
        for (ChatRoom cr : chatRoomArrayList) {
            if (cr.getId().equals(chatRoomId)) {
                int index = chatRoomArrayList.indexOf(cr);
                cr.setLastMessage(message.getMessage());
                cr.setUnreadCount(cr.getUnreadCount() + 1);
                chatRoomArrayList.remove(index);
                chatRoomArrayList.add(index, cr);
                break;
            }
        }
        mAdapter.notifyDataSetChanged();
    }


    /**
     * fetching the chat rooms by making http call
     */
    private void fetchChatRooms() {
        StringRequest strReq = new StringRequest(Request.Method.GET,
                EndPoints.CHAT_ROOMS, new Response.Listener<String>() {

            @Override
            public void onResponse(String response) {
                Log.e(TAG, "response: " + response);

                try {
                    JSONObject obj = new JSONObject(response);

                    // check for error flag
                    if (obj.getBoolean("error") == false) {
                        JSONArray chatRoomsArray = obj.getJSONArray("chat_rooms");
                        for (int i = 0; i < chatRoomsArray.length(); i++) {
                            JSONObject chatRoomsObj = (JSONObject) chatRoomsArray.get(i);
                            ChatRoom cr = new ChatRoom();
                            cr.setId(chatRoomsObj.getString("user_id"));
                            cr.setName(chatRoomsObj.getString("name"));
                            cr.setLastMessage("");
                            cr.setUnreadCount(0);
                            cr.setTimestamp(chatRoomsObj.getString("created_at"));

                            chatRoomArrayList.add(cr);
                        }

                    } else {
                        // error in fetching chat rooms
                        Toast.makeText(getApplicationContext(), "" + obj.getJSONObject("error").getString("message"), Toast.LENGTH_LONG).show();
                    }

                } catch (JSONException e) {
                    Log.e(TAG, "json parsing error: " + e.getMessage());
                    Toast.makeText(getApplicationContext(), "Json parse error: " + e.getMessage(), Toast.LENGTH_LONG).show();
                }

                mAdapter.notifyDataSetChanged();

                // subscribing to all chat room topics
                //subscribeToAllTopics();
            }
        }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                NetworkResponse networkResponse = error.networkResponse;
                Log.e(TAG, "Volley error: " + error.getMessage() + ", code: " + networkResponse);
                Toast.makeText(getApplicationContext(), "Volley error: " + error.getMessage(), Toast.LENGTH_SHORT).show();
            }
        });

        //Adding request to request queue
        MyApplication.getInstance().addToRequestQueue(strReq);
    }

    // subscribing to global topic
    private void subscribeToGlobalTopic() {
        Intent intent = new Intent(this, GcmIntentService.class);
        intent.putExtra(GcmIntentService.KEY, GcmIntentService.SUBSCRIBE);
        intent.putExtra(GcmIntentService.TOPIC, Config.TOPIC_GLOBAL);
        startService(intent);
    }

    // Subscribing to all chat room topics
    // each topic name starts with `topic_` followed by the ID of the chat room
    // Ex: topic_1, topic_2
    /*private void subscribeToAllTopics() {
        for (ChatRoom cr : chatRoomArrayList) {

            Intent intent = new Intent(this, GcmIntentService.class);
            intent.putExtra(GcmIntentService.KEY, GcmIntentService.SUBSCRIBE);
            intent.putExtra(GcmIntentService.TOPIC, "topic_" + cr.getId());
            startService(intent);
        }
    }*/

    private void launchLoginActivity() {
        Intent intent = new Intent(MainActivity.this, LoginActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        startActivity(intent);
        finish();
    }

    @Override
    protected void onResume() {
        super.onResume();

        // register GCM registration complete receiver
        LocalBroadcastManager.getInstance(this).registerReceiver(mRegistrationBroadcastReceiver,
                new IntentFilter(Config.REGISTRATION_COMPLETE));

        // register new push message receiver
        // by doing this, the activity will be notified each time a new message arrives
        LocalBroadcastManager.getInstance(this).registerReceiver(mRegistrationBroadcastReceiver,
                new IntentFilter(Config.PUSH_NOTIFICATION));

        // clearing the notification tray
        NotificationUtils.clearNotifications();
    }

    @Override
    protected void onPause() {
        LocalBroadcastManager.getInstance(this).unregisterReceiver(mRegistrationBroadcastReceiver);
        super.onPause();
    }

    // starting the service to register with GCM
    private void registerGCM() {
        Intent intent = new Intent(this, GcmIntentService.class);
        intent.putExtra("key", "register");
        startService(intent);
    }

    private boolean checkPlayServices() {
        GoogleApiAvailability apiAvailability = GoogleApiAvailability.getInstance();
        int resultCode = apiAvailability.isGooglePlayServicesAvailable(this);
        if (resultCode != ConnectionResult.SUCCESS) {
            if (apiAvailability.isUserResolvableError(resultCode)) {
                apiAvailability.getErrorDialog(this, resultCode, PLAY_SERVICES_RESOLUTION_REQUEST)
                        .show();
            } else {
                Log.i(TAG, "This device is not supported. Google Play Services not installed!");
                Toast.makeText(getApplicationContext(), "This device is not supported. Google Play Services not installed!", Toast.LENGTH_LONG).show();
                finish();
            }
            return false;
        }
        return true;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.menu_main, menu);
        return true;
    }

    public boolean onOptionsItemSelected(MenuItem menuItem) {
        switch (menuItem.getItemId()) {
            case R.id.action_logout:
                MyApplication.getInstance().logout();
                break;
        }
        return super.onOptionsItemSelected(menuItem);
    }
}

ChatRoomsAdapter ：

package com.wipro.chat.adapter;

/**
 * Created by COMP on 16-06-2016.
 */
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.GestureDetector;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;

import com.wipro.chat.R;
import com.wipro.chat.model.ChatRoom;


public class ChatRoomsAdapter extends RecyclerView.Adapter<ChatRoomsAdapter.ViewHolder> {

    private Context mContext;
    private ArrayList<ChatRoom> chatRoomArrayList;
    private static String today;

    public class ViewHolder extends RecyclerView.ViewHolder {
        public TextView name, message, timestamp, count;

        public ViewHolder(View view) {
            super(view);
            name = (TextView) view.findViewById(R.id.name);
            message = (TextView) view.findViewById(R.id.message);
            timestamp = (TextView) view.findViewById(R.id.timestamp);
            count = (TextView) view.findViewById(R.id.count);
        }
    }


    public ChatRoomsAdapter(Context mContext, ArrayList<ChatRoom> chatRoomArrayList) {
        this.mContext = mContext;
        this.chatRoomArrayList = chatRoomArrayList;

        Calendar calendar = Calendar.getInstance();
        today = String.valueOf(calendar.get(Calendar.DAY_OF_MONTH));
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.chat_rooms_list_row, parent, false);

        return new ViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        ChatRoom chatRoom = chatRoomArrayList.get(position);
        holder.name.setText(chatRoom.getName());
        holder.message.setText(chatRoom.getLastMessage());
        if (chatRoom.getUnreadCount() > 0) {
            holder.count.setText(String.valueOf(chatRoom.getUnreadCount()));
            holder.count.setVisibility(View.VISIBLE);
        } else {
            holder.count.setVisibility(View.GONE);
        }

        holder.timestamp.setText(getTimeStamp(chatRoom.getTimestamp()));
    }

    @Override
    public int getItemCount() {
        return chatRoomArrayList.size();
    }

    public static String getTimeStamp(String dateStr) {
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String timestamp = "";

        today = today.length() < 2 ? "0" + today : today;

        try {
            Date date = format.parse(dateStr);
            SimpleDateFormat todayFormat = new SimpleDateFormat("dd");
            String dateToday = todayFormat.format(date);
            format = dateToday.equals(today) ? new SimpleDateFormat("hh:mm a") : new SimpleDateFormat("dd LLL, hh:mm a");
            String date1 = format.format(date);
            timestamp = date1.toString();
        } catch (ParseException e) {
            e.printStackTrace();
        }

        return timestamp;
    }

    public interface ClickListener {
        void onClick(View view, int position);

        void onLongClick(View view, int position);
    }

    public static class RecyclerTouchListener implements RecyclerView.OnItemTouchListener {

        private GestureDetector gestureDetector;
        private ChatRoomsAdapter.ClickListener clickListener;

        public RecyclerTouchListener(Context context, final RecyclerView recyclerView, final ChatRoomsAdapter.ClickListener clickListener) {
            this.clickListener = clickListener;
            gestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
                @Override
                public boolean onSingleTapUp(MotionEvent e) {
                    return true;
                }

                @Override
                public void onLongPress(MotionEvent e) {
                    View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
                    if (child != null && clickListener != null) {
                        clickListener.onLongClick(child, recyclerView.getChildLayoutPosition(child));
                    }
                }
            });
        }

        @Override
        public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {

            View child = rv.findChildViewUnder(e.getX(), e.getY());
            if (child != null && clickListener != null && gestureDetector.onTouchEvent(e)) {
                clickListener.onClick(child, rv.getChildLayoutPosition(child));
            }
            return false;
        }

        @Override
        public void onTouchEvent(RecyclerView rv, MotionEvent e) {
        }

        @Override
        public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {

        }
    }
}

检索聊天室的PHP代码如下：

/* * *
 * fetching all chat rooms
 */
$app->get('/chat_rooms', function() {
    $response = array();
    $db = new DbHandler();

    // fetching all user tasks
    $result = $db->getAllChats();

    $response["error"] = false;
    $response["chat_rooms"] = array();

    // pushing single chat room into array
    while ($chat_room = $result->fetch_assoc()) {
        $tmp = array();
        $tmp["user_id"] = $chat_room["user_id"];
        $tmp["name"] = $chat_room["name"];
        $tmp["created_at"] = $chat_room["created_at"];
        array_push($response["chat_rooms"], $tmp);
    }

    echoRespnse(200, $response);
});
public function getAllChats() {
        $stmt = $this->conn->prepare("SELECT user_id, name, created_at FROM users");
        $stmt->execute();
        $tasks = $stmt->get_result();
        $stmt->close();
        return $tasks;
    }

我的数据库中有两个用户聊天，即 Messaging ， Chat ，我从数据库到ArrayList，但它只显示信息

适配器显示：

来自数据库的响应：

Answer 1

检查主布局中的"wrap_content"。高度应设置为ProgressBar。

ArrayList仅显示RecyclerView

1 个答案: