修复会话列表加载数据的逻辑问题

rong_im/kit/src/main/java/io/rong/imkit/conversationlist/viewmodel/ConversationListViewModel.java

@@ -161,15 +161,22 @@ public class ConversationListViewModel extends AndroidViewModel {
                 RongIMClient.getInstance().getConversationListByPage(new RongIMClient.ResultCallback<List<Conversation>>() {
                     @Override
                     public void onSuccess(List<Conversation> conversations) {
-                        mUiConversationList.clear();
                         if (loadMore) {
                             mRefreshEventLiveData.postValue(new Event.RefreshEvent(RefreshState.LoadFinish));
                         } else {
                             mRefreshEventLiveData.postValue(new Event.RefreshEvent(RefreshState.RefreshFinish));
                         }
                         if (conversations == null || conversations.size() == 0) {
-                            mConversationListLiveData.postValue(new ArrayList<BaseUiConversation>());
+                            if (loadMore) {
+                                //没有更多
+                            } else {
+                                mConversationListLiveData.postValue(new ArrayList<BaseUiConversation>());
+                            }
                             return;
+                        } else {
+                            if (!loadMore) {
+                                mUiConversationList.clear();
+                            }
                         }
                         RLog.d(TAG, "getConversationListByPage. size:" + conversations.size());
                         mLastSyncTime = conversations.get(conversations.size() - 1).getSentTime();