从服务器进入 RecyclerView 时实时更新数据

Question

我正在从 Websockets 获取 json 并在回收器视图中显示。从 websockets 获取数据时如何实时更新列表？

我的 WebSocket 类

 public final class EchoWebSocketListener extends WebSocketListener {
    private static final int NORMAL_CLOSURE_STATUS = 1000;
    private static final String TAG = "DashBoardScreen.this";

    @Override
    public void onOpen(WebSocket webSocket, Response response) {
        super.onOpen(webSocket, response);

最初建立连接时，我会向服务器发送一些文本

  webSocket.send(builder.toString());
    }

    @Override
    public void onMessage(WebSocket webSocket, String text) {
        super.onMessage(webSocket, text);

在返回服务器向我发送数据

 output(text);
    }

    @Override
    public void onMessage(WebSocket webSocket, ByteString bytes) {
        super.onMessage(webSocket, bytes);
    }

    @Override
    public void onClosing(WebSocket webSocket, int code, String reason) {
        super.onClosing(webSocket, code, reason);
        Log.d(TAG, "onClosing: ");
    }

    @Override
    public void onClosed(WebSocket webSocket, int code, String reason) {
        super.onClosed(webSocket, code, reason);
        Log.d(TAG, "onClosed: ");
    }

    @Override
    public void onFailure(WebSocket webSocket, Throwable t,Response response) {
        super.onFailure(webSocket, t, response);
        Log.d(TAG, "onFailure: ");
    }
}

输出方法

 private void output(final String text) {

 runOnUiThread(new Runnable() {
            @Override
            public void run() {
             *parsing json inside recyler view*

                    try {
                        JSONObject object = new JSONObject(text);
                        StringBuilder builder = new StringBuilder();
                        if (object.getBoolean("status")) {
                            JSONArray jsonArray = object.getJSONArray("events");
                            for (int i = 0; i < jsonArray.length(); i++) {
                                JSONObject values = jsonArray.getJSONObject(i);
                                final EventsDataModel dataModel = new EventsDataModel(
                                        values.getString("service_Room_Number"),
                                        values.getString("service_Name"),
                                        values.getString("service_AssignedTo"),
                                        values.getString("service_ID")
                                );                       
                                eventsDataModels.add(dataModel);
                                adapter = new EventListAdapter(eventsDataModels, context);
                                eventRecyclerView.setAdapter(adapter);
                                adapter.notifyDataSetChanged(); 

notifyDataSetChanged() 究竟是如何工作的？

                            }
                        } else Toast.makeText(context, "No Events", Toast.LENGTH_SHORT).show();
                        System.out.println(builder.append(object.getString("status")));

                    } catch (JSONException e) {
                        e.printStackTrace();
                    }

            }
        });
    }

Answer 1

每当你的 dataModel 有新数据时

eventsDataModels.add(dataModel); adapter = new EventListAdapter(eventsDataModels, context); eventRecyclerView.setAdapter(adapter);

如果执行上述操作并执行adapter.notifyDataSetChanged(); 将通知适配器新数据已到达，并且必须使用新的 dataModel 更新 RecyclerView。