适配器之值传递（fragment适配器获得listview控件对象）

墨蓝 2024-02-17 16:55 53阅读 0赞

@Override
            public void handleMessage(android.os.Message message) {
                switch (message.what) {
                    case HANDLER_MESSAGE_REFRESH_LIST:
                        refreshList();
                        break;
                    case HANDLER_MESSAGE_SELECT_LAST:
                        if (activity instanceof ChatContainerActivity) {
                            ListView listView_fragment = chatLookerFragment.getRecyclerView();
                            if (messages.length > 0) {
                                listView_fragment.setSelection(messages.length - 1);
                            }
                            ListView listView = ((ChatContainerActivity) activity).getListView();
                            if (messages.length > 0) {
                                listView.setSelection(messages.length - 1);
                            }
                        }
                        break;
                    case HANDLER_MESSAGE_SEEK_TO:
                        int position = message.arg1;
                        if (activity instanceof ChatContainerActivity) {
                            ListView listView = ((ChatContainerActivity) activity).getListView();
                            listView.setSelection(position);
                        }
                        break;
                    default:
                        break;
                }
            }

chatLookerFragment.getRecyclerView();  
这个是重点；  
我之前通过单例模式获得实例，不能获得到listview对象，报空针

public static ChatLookerFragment newInstance() {
            ChatLookerFragment fragment = new ChatLookerFragment();
            return fragment;
        }
    
        public ChatLookerFragment() {
        }

我的解决办法是在adapter的适配器中传入fragment的实例，通过该实例获得listview对象

public MyChatMsgAdapter(EMConversation conversation, ChatContainerActivity mcontext, String username, ChatLookerFragment chatLookerFragment) {
    //        this.conversation = conversation;
            this.conversation = EMChatManager.getInstance().getConversation(username);
            this.mcontext = mcontext;
            activity = mcontext;
            this.chatLookerFragment = chatLookerFragment;
        }