0
我有一個自定義對象的ArrayList。這個ArrayList傳遞給我的RecyclerView適配器。當事件發生時，我需要從ArrayList中檢索包含具有唯一值的變量的對象，對該對象進行更改，然後重新加載與該對象相對應的ViewHolder。我如何實現這一目標？如何重新加載recyclerview行而無需列表的位置？
問題是我沒有在ArrayList中的對象的位置，因爲位置不斷動態變化。我只有這個獨特的價值對應於我想要改變的對象。我試着做list.clear（）然後重新分配對象與ArrayList與更新的值，然後調用adapter.notifyDataSetChanged（），但它不起作用。
編輯： 我提供以下含有recyclerview活動的代碼。實際的代碼要大得多，所以我決定編輯它只顯示關於這個問題的必要細節。請讓我知道是否需要添加更多代碼。
因此，基本上這裏發生的事情是，IMActivity綁定到服務並在綁定時將其上下文傳遞給服務。當服務中發生事件時，數據庫值發生更改，並在服務中調用updateActivity（）。
我想要updateActivity（）做的是檢查chatMsg對象的chatMsg對象，該對象包含一個具有唯一值的變量並重新加載對應於該ChatMsg對象的視圖。
請讓我知道，如果我需要進一步澄清。
public class IMActivity extends AppCompatActivity implements Sertivity {
private RecyclerView recyclerView;
private ImAdapter imAdapter;
private List<ChatMsg> chatMsgList = new ArrayList<>();
EditText etIM;
ImageButton ibSend;
TalkSeeService.TalkSeeBinder talkSeeBinder;
String usernames[]= new String[10];
String otherUserName;
List<Msg> msgList;
DBAct db;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
bindService(new Intent(com.abdralabs.talksee.IMActivity.this, TalkSeeService.class), new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
talkSeeBinder = (TalkSeeService.TalkSeeBinder)service;
talkSeeBinder.setSertivity(com.abdralabs.talksee.IMActivity.this);
}
@Override
public void onServiceDisconnected(ComponentName name) {
talkSeeBinder.setSertivity(null);
talkSeeBinder = null;
}
},BIND_AUTO_CREATE);
setContentView(R.layout.activity_im);
recyclerView = (RecyclerView)findViewById(R.id.rv_im);
imAdapter = new ImAdapter(chatMsgList);
LinearLayoutManager layoutManager = new LinearLayoutManager(getApplicationContext());
layoutManager.setStackFromEnd(true);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setAdapter(imAdapter);
ibSend = (ImageButton)findViewById(R.id.ib_send);
etIM = (EditText)findViewById(R.id.et_im);
ibSend.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//THE TEXT FROM THE EDITTEXT IS TAKEN AND THEN ADDED TO THE DATABASE
updateChatData();
}
});
db = new DBAct(com.abdralabs.talksee.IMActivity.this,otherUserName);
msgList = db.getAllMessages();
db.close();
prepareChatData();
}
private void prepareChatData() {
for (int i=0; i<msgList.size(); i++) {
ChatMsg chatMsg = new ChatMsg(msgList.get(i).getMessage(),
convertToDayDateTime(Long.valueOf(msgList.get(i).getTime())),
msgList.get(i).getOther(),
getReceiptFromDelivered(i));
chatMsgList.add(chatMsg);
}
imAdapter.notifyDataSetChanged();
}
private void updateChatData(){
msgList = db.getAllMessages();
db.close();
int i = msgList.size() - 1;
ChatMsg chatMsg = new ChatMsg(msgList.get(i).getMessage(),
convertToDayDateTime(Long.valueOf(msgList.get(i).getTime())),
msgList.get(i).getOther(),
getReceiptFromDelivered(i));
chatMsgList.add(chatMsg);
imAdapter.notifyDataSetChanged();
recyclerView.smoothScrollToPosition(imAdapter.getItemCount());
}
@Override
public void updateActivity() {
chatMsgList.clear();
prepareChatData();
recyclerView.smoothScrollToPosition(imAdapter.getItemCount());
}
@Override
public void callActivityMethod() {
updateChatData();
}
private String convertToDayDateTime(long timestamp){
Calendar cal = Calendar.getInstance();
TimeZone tz = cal.getTimeZone();
SimpleDateFormat sdf = new SimpleDateFormat("EEE dd/MM/yyyy HH:mm");
sdf.setTimeZone(tz);
String localTime = sdf.format(new Date(timestamp));
return localTime;
}
private String getReceiptFromDelivered(int position){
String receipt;
if (msgList.get(position).getDelivered().equals("0")){
receipt = "...";
}else {
receipt = "S";
}
return receipt;
}
}
IMAdapter.java
public class ImAdapter extends RecyclerView.Adapter <RecyclerView.ViewHolder> {
private List<ChatMsg> chatMsgList = new ArrayList<ChatMsg>();
final int VIEW_TYPE_USER = 1;
final int VIEW_TYPE_OTHER = 0;
public ImAdapter(List<ChatMsg> chatMsgList){
this.chatMsgList = chatMsgList;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType==VIEW_TYPE_USER){
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_chat_msg_user,parent,false);
return new ImUserViewHolder(itemView);
}
else {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_chat_msg_other,parent,false);
return new ImOtherViewHolder(itemView);
}
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (holder.getItemViewType()==VIEW_TYPE_USER){
ChatMsg chatMsg = chatMsgList.get(position);
ImUserViewHolder imUserViewHolder = (ImUserViewHolder)holder;
imUserViewHolder.msg.setText(chatMsg.getMsg());
imUserViewHolder.timeStamp.setText(chatMsg.getTime());
}
else {
ChatMsg chatMsg = chatMsgList.get(position);
ImOtherViewHolder imOtherViewHolder = (ImOtherViewHolder) holder;
imOtherViewHolder.msg.setText(chatMsg.getMsg());
imOtherViewHolder.timeStamp.setText(chatMsg.getTime());
}
}
@Override
public int getItemViewType(int position) {
ChatMsg chatMsg = chatMsgList.get(position);
if (chatMsg.getOther().equals("true")){
return VIEW_TYPE_OTHER;
}
else {
return VIEW_TYPE_USER;
}
}
@Override
public int getItemCount() {
return chatMsgList.size();
}
public class ImOtherViewHolder extends RecyclerView.ViewHolder{
public TextView msg;
public TextView timeStamp;
public ImOtherViewHolder(View itemView) {
super(itemView);
msg = (TextView)itemView.findViewById(R.id.tv_chat_msg_other);
timeStamp = (TextView)itemView.findViewById(R.id.tv_time_chat_msg_other);
}
}
public class ImUserViewHolder extends RecyclerView.ViewHolder{
public TextView msg;
public TextView timeStamp;
public ImUserViewHolder(View itemView) {
super(itemView);
msg = (TextView)itemView.findViewById(R.id.tv_chat_msg_user);
timeStamp = (TextView)itemView.findViewById(R.id.tv_time_chat_msg_user);
}
}
}
請，把你的代碼在這裏。 –
發佈你迄今爲止所做的事情，看看你在哪裏。 –
我在編輯中提供了代碼。請檢查。 –