我正在处理这个聊天应用程序。在那，我想在回收站视图中搜索特定的消息。为此，我使用Filterable接口。当我尝试使用arraylist更新notifydatasetchange()时，它不会更改arraylist项。它保持不变。
这是我的适配器代码。
MessageAdapter.java
package com.android.customizedchat;
import java.lang.*;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.widget.RecyclerView;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.*;
import android.widget.BaseAdapter;
import android.widget.ArrayAdapter;
import android.app.Activity;
import android.content.Context;
import android.widget.Filter;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.*;
public class MessageAdapter extends RecyclerView.Adapter<MessageAdapter.ViewHolder> implements Filterable {
List<Message> filteredmessageList;
List<Message> messages;
public MessageAdapter(List<Message> objects){
this.messages = objects;
this.filteredmessageList = objects;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_message,parent,false);
return new ViewHolder(v);
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
Message message = messages.get(position);
boolean myMsg=message.getIsMe();
setAlingnment(holder,myMsg);
holder.message.setText(message.getText());
holder.user.setText(message.getName());
holder.timestamp.setText(message.getTimestamp());
System.out.println("From Holder: "+holder.message.getText());
}
public void setAlingnment(ViewHolder holder,boolean isMe){
if(!isMe){
holder.message.setGravity(Gravity.LEFT);
holder.user.setGravity(Gravity.LEFT);
holder.timestamp.setGravity(Gravity.LEFT);
}else {
holder.message.setGravity(Gravity.RIGHT);
holder.user.setGravity(Gravity.RIGHT);
holder.timestamp.setGravity(Gravity.RIGHT);
}
}
@Override
public int getItemCount() {
return messages.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
public TextView message;
public TextView user;
public TextView timestamp;
public ImageView message_image;
public ViewHolder(View view){
super(view);
message = (TextView) view.findViewById(R.id.messageTextView);
user = (TextView)view.findViewById(R.id.nameTextView);
timestamp = (TextView) view.findViewById(R.id.messageTimeStamp);
message_image = (ImageView) view.findViewById(R.id.messageImageView);
}
}
public Filter getFilter(){
return new Filter() {
@Override
protected FilterResults performFiltering(CharSequence constraint) {
System.out.println("Enter Filtering");
String charString = constraint.toString();
if(charString.isEmpty()){
filteredmessageList = messages;
}
else{
List<Message> filterlist = new ArrayList<>();
for(Message row : messages){
if(row.getText().toLowerCase().contains(charString.toLowerCase())){
filterlist.add(row);
}
}
filteredmessageList = filterlist;
}
FilterResults filterResults = new FilterResults();
filterResults.values = filteredmessageList;
System.out.println(filterResults.values.toString());
return filterResults;
}
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
filteredmessageList = (ArrayList<Message>) results.values;
for (int i = 0; i < filteredmessageList.size(); i++) {
System.out.println(filteredmessageList.get(i).getText());
}
// notifyDataSetChanged();
}
};
}
}
这是我的主要活动文件
MainActivity.java
package com.android.customizedchat;
import android.content.Intent;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.*;
import android.widget.*;
import android.support.v7.widget.SearchView;
import java.net.URISyntaxException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.*;
import android.view.*;
import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.StringRequest;
import com.github.nkzawa.emitter.Emitter;
import com.github.nkzawa.socketio.client.IO;
import com.github.nkzawa.socketio.client.Socket;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class MainActivity extends AppCompatActivity {
public RecyclerView messageListView;
public MessageAdapter messageAdapter;
public EditText messageEditText;
public Button messageSendButton;
String TimeStamp="";
public List<Message> message;
private Socket socket;{
try{
socket = IO.socket("http://192.168.137.1:3000");
// socket = IO.socket("https://customizedchat.herokuapp.com");
}
catch (URISyntaxException e){
throw new RuntimeException(e);
}
}
public String username;
//public String url_connect ="http://192.168.137.1/test/retrivemessage.php";
public String url_connect = "http://wallstreet.000webhostapp.com/retrivemessage.php";
//public String url_insert = "http://192.168.137.1/test/insertmessage.php";
public String url_insert = "http://wallstreet.000webhostapp.com/insertmessage.php";
public String uname,msgs,tstamp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Bundle bundle = getIntent().getExtras();
String GroupID = bundle.getString("GroupID");
final String GroupName = bundle.getString("GroupName");
Toast.makeText(this, "ID"+GroupID+"Name"+GroupName, Toast.LENGTH_SHORT).show();
setTitle(GroupName);
socket.connect();
socket.emit("subscribe",GroupName);
socket.on("newM",handleIncomingMessages);
SharedPreferences pref = getApplicationContext().getSharedPreferences("MyPref",0);
username=pref.getString("uname",null);
messageListView=(RecyclerView)findViewById(R.id.messageListView);
messageListView.setLayoutManager(new LinearLayoutManager(this));
messageEditText=(EditText)findViewById(R.id.messageEditText);
messageSendButton=(Button)findViewById(R.id.messageSendButton);
message =new ArrayList<>();
messageAdapter=new MessageAdapter(message);
messageListView.setAdapter(messageAdapter);
messageSendButton.setEnabled(true);
StringRequest stringRequest = new StringRequest(Request.Method.POST, url_connect, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
try{
String res = response;
JSONArray msgs = new JSONArray(res);
for(int i=0;i<msgs.length();i++){
JSONObject msg =(JSONObject) msgs.get(i);
String status = msg.getString("code");
if(status.equals("success")){
String mesg = msg.getString("Message");
String uname = msg.getString("Username");
String tstamp = msg.getString("TimeStamp");
Message message1 = new Message(mesg,uname,tstamp);
if(uname.equals(username))
message1.setMe(true);
addMessage(message1);
}
else{
Toast.makeText(MainActivity.this, "The table for this group has been created in database", Toast.LENGTH_SHORT).show();
}
}
}catch (JSONException e){
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(MainActivity.this, ""+error.getMessage(), Toast.LENGTH_SHORT).show();
}
}){
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String,String> params=new HashMap<String,String>();
params.put("grpname",GroupName);
return params;
}
};
Connection.getInstance(getApplicationContext()).addToRequestQueue(stringRequest);
messageSendButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(!(messageEditText.getText().toString().trim().equals(""))) {
// final String time = DateFormat.getTimeInstance(DateFormat.SHORT).format(new Date());\
Date dt = new Date();
long time = dt.getTime();
if (android.text.format.DateFormat.is24HourFormat(MainActivity.this)) {
TimeStamp = new SimpleDateFormat("hh:mm a", Locale.US).format(new Date(time));
}
else{
TimeStamp = DateFormat.getTimeInstance(DateFormat.SHORT).format(new Date());
}
final String msg =messageEditText.getText().toString().trim();
Message message = new Message(msg, username,TimeStamp);
message.setMe(true);
StringRequest insert = new StringRequest(Request.Method.POST, url_insert, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
Toast.makeText(MainActivity.this, ""+response, Toast.LENGTH_SHORT).show();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(MainActivity.this, ""+error.getMessage(), Toast.LENGTH_SHORT).show();
}
}){
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String,String> params=new HashMap<String,String>();
params.put("grpname",GroupName);
params.put("message",msg);
params.put("username",username);
params.put("timestamp",TimeStamp);
return params;
}
};
Connection.getInstance(getApplicationContext()).addToRequestQueue(insert);
String MESSAGGE = messageEditText.getText().toString().trim();
addMessage(message);
messageEditText.setText("");
try {
JSONObject object = new JSONObject();
object.put("message", MESSAGGE);
object.put("userid", username);
object.put("timestamp",TimeStamp);
object.put("room",GroupName);
socket.emit("newM", object);
} catch (JSONException e) {
e.printStackTrace();
}
}
else
Toast.makeText(MainActivity.this, "Enter text", Toast.LENGTH_SHORT).show();
}
});
}
//for handeling incoming messages
private Emitter.Listener handleIncomingMessages = new Emitter.Listener() {
@Override
public void call(final Object... args) {
runOnUiThread(new Runnable() {
@Override
public void run() {
JSONObject data=(JSONObject) args[0];
String message,uname,tstamp;
try {
message=data.getString("message").toString().trim();
uname = data.getString("uname").toString();
tstamp = data.getString("tstamp").toString();
//System.out.println("------------------------------------------------------"+uname+" : "+message);
Message msg=new Message(message,uname,tstamp);
msg.setMe(false);
addMessage(msg);
}catch (JSONException e){
return;
}
}
});
}
};
@Override
protected void onDestroy() {
super.onDestroy();
socket.disconnect();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu,menu);
MenuItem item = menu.findItem(R.id.actionSearch);
//SearchView searchView = (SearchView) item.getActionView();
android.support.v7.widget.SearchView searchView = (android.support.v7.widget.SearchView) item.getActionView();
searchView.setOnQueryTextListener(new android.support.v7.widget.SearchView.OnQueryTextListener() {
@Override
public boolean onQueryTextSubmit(String query) {
return false;
}
@Override
public boolean onQueryTextChange(String newText) {
messageAdapter.getFilter().filter(newText);
messageAdapter.notifyDataSetChanged();
return false;
}
});
return super.onCreateOptionsMenu(menu);
}
public String getUsername(){
return username;
}
public void addMessage(Message m){
message.add(m);
messageAdapter = new MessageAdapter(message);
messageAdapter.notifyItemInserted(0);
messageListView.scrollToPosition(messageAdapter.getItemCount()-1);
}
}
当我在控制台上打印过滤后的值时，它打印完美。但它并没有更新回收者视图的列表。
如果有人能够帮助我找到解决方案，那将会非常有帮助。
答案 0 :(得分：0)
在通知适配器之前，您必须更新message列表，此方法如下：
@Override
public boolean onQueryTextChange(String newText) {
messageAdapter.getFilter().filter(newText);
messageAdapter.notifyDataSetChanged();
return false;
}