我正在尝试在新邮件到达时刷新ListView，但是一旦添加了邮件，我似乎无法刷新listview / adapter。 NotifyDataSetChangers()似乎不起作用。任何帮助将不胜感激。
MessagingActivity
public class MessagingActivity extends AppCompatActivity implements AdapterView.OnItemClickListener{
UserCredentialHandler userCredentialHandler;
ListView chatListView;
List<ChatRowItem> chatRowItems;
List<Message> messagesList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_messaging);
userCredentialHandler = new UserCredentialHandler();
Button bMsgJas = (Button)findViewById(R.id.bJas);
Button bMsgTest = (Button)findViewById(R.id.bTest);
Button bSendMsg = (Button)findViewById(R.id.button_send_message);
final EditText inputText = (EditText)findViewById(R.id.chat_enter_message);
final String userH = "h@h.com";
final String userT = "test@test.com";
chatRowItems = new ArrayList<>();
final ChatCustomAdapter adapter = new ChatCustomAdapter(this, chatRowItems);
chatListView = (ListView)findViewById(R.id.chat_listview);
chatListView.setAdapter(adapter);
chatListView.setOnItemClickListener(this);
bMsgJas.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
SendBird.startMessaging(userH);
}
});
bMsgTest.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
SendBird.startMessaging(userT);
}
});
bSendMsg.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String newMsg = inputText.getText().toString();
SendBird.send(newMsg);
}
});
SendBird.setEventHandler(new SendBirdEventHandler() {
@Override
public void onConnect(Channel channel) {
}
@Override
public void onError(int i) {
}
@Override
public void onChannelLeft(Channel channel) {
}
@Override
public void onMessageReceived(Message message) {
messagesList.add(message);
adapter.updateChatList(chatRowItems);
}
@Override
public void onSystemMessageReceived(SystemMessage systemMessage) {
}
@Override
public void onBroadcastMessageReceived(BroadcastMessage broadcastMessage) {
}
@Override
public void onFileReceived(FileLink fileLink) {
}
@Override
public void onReadReceived(ReadStatus readStatus) {
}
@Override
public void onTypeStartReceived(TypeStatus typeStatus) {
}
@Override
public void onTypeEndReceived(TypeStatus typeStatus) {
}
@Override
public void onAllDataReceived(SendBird.SendBirdDataType sendBirdDataType, int i) {
}
@Override
public void onMessageDelivery(boolean b, String s, String s1, String s2) {
}
@Override
public void onMessagingStarted(final MessagingChannel messagingChannel) {
SendBird.queryMessageList(messagingChannel.getUrl()).load(Long.MAX_VALUE, 30, 10, new MessageListQuery.MessageListQueryResult() {
@Override
public void onResult(List<MessageModel> messageModels) {
messagesList = (List<Message>)(List<?>) messageModels;
for(int i = 0; i < messageModels.size(); i++){
drawListRows(messagesList.get(i));
}
SendBird.join(messagingChannel.getUrl());
SendBird.connect();
}
@Override
public void onError(Exception e) {
}
});
}
@Override
public void onMessagingUpdated(MessagingChannel messagingChannel) {
}
@Override
public void onMessagingEnded(MessagingChannel messagingChannel) {
}
@Override
public void onAllMessagingEnded() {
}
@Override
public void onMessagingHidden(MessagingChannel messagingChannel) {
}
@Override
public void onAllMessagingHidden() {
}
});
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
//final String member_list_id = rowItems.get(position).bookListId;
}
public void drawListRows(Message msg){
ChatRowItem item = new ChatRowItem(msg.getSenderName(), msg.getMessage(), msg.getTimestamp());
chatRowItems.add(item);
}
// public void updateChatList(List<ChatRowItem> chatItems){
// messagesList.clear();
// messagesList.addAll(newMsgList);
}
ChatCustomAdapter
public class ChatCustomAdapter extends BaseAdapter {
List<ChatRowItem> chatRowItemList;
Context context;
ChatCustomAdapter(Context context, List<ChatRowItem> chatRowItemList){
this.chatRowItemList = chatRowItemList;
this.context = context;
}
@Override
public int getCount(){
return chatRowItemList.size();
}
@Override
public Object getItem(int position){
return chatRowItemList.get(position);
}
@Override
public long getItemId(int position){
return chatRowItemList.indexOf(getItem(position));
}
private class ViewHolder {
TextView username;
TextView message;
TextView timestamp;
}
@Override
public View getView(int position, View convertView, ViewGroup parent){
ViewHolder holder = null;
LayoutInflater mInflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
if(convertView == null ) {
convertView = mInflater.inflate(R.layout.chat_msg_item, null);
holder = new ViewHolder();
holder.message = (TextView)convertView.findViewById(R.id.chat_message_text);
holder.username = (TextView)convertView.findViewById(R.id.chat_user_id);
holder.timestamp = (TextView)convertView.findViewById(R.id.chat_timestamp);
ChatRowItem row_pos = chatRowItemList.get(position);
holder.message.setText(row_pos.message);
holder.username.setText(row_pos.userId);
// holder.timestamp.setText((int)row_pos.timestamp);
convertView.setTag(holder);
} else {
holder = (ViewHolder)convertView.getTag();
}
return convertView;
}
public void updateChatList(List<ChatRowItem> chatItems){
chatRowItemList.clear();
chatItems.addAll(chatItems);
this.notifyDataSetChanged();
}
}
答案 0 :(得分：2)
chatItems.addAll(chatItems);
应该是
chatRowItemList.addAll(chatItems);
但这还不够。 chatRowItemList.clear();正在删除chatRowItems中的所有项目，因为您将其作为对Adapter的构造函数的引用传递。
答案 1 :(得分：0)
我认为再次设置适配器可以解决