从服务器进入RecylerView时实时更新数据

时间:2019-02-26 09:06:03

标签: java android android-recyclerview java-websocket

我正在从Websockets获取json并显示在recyler视图中。从Websocket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);

最初建立连接后,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);

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()的工作原理如何?

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

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

            }
        });
    }

1 个答案:

答案 0 :(得分:0)

只要您的dataModel有新数据

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经到达,并且必须使用新的dataModel更新RecyclerView。