Question

我在java类中使用JsonObjectRequest和Volley发出请求，一旦我获得数据，我就无法将它发送到我需要使用它的活动。我尝试使用回调，但我不知道我做错了什么。我尝试了几件事，但都没有奏效。我在请求类中正确获取数据，因此问题是从活动中获取数据。

我认为我的问题与回调有关，但正如我所说，我已尽力而为。

任何帮助将不胜感激！

这是我的请求代码：

public ArrayList<Coin> getMarketSummary(final DashboardActivity.CoinCallback callback, ArrayList<Coin> listAux, Context context) {

Log.d("chegamos a entrar en getCOinData??", "Entramos en getMarketSummary");

listCoins.clear();

requestQueue = Volley.newRequestQueue(context);

for (Coin coinAux : listAux) {
    this.coin = coinAux;

    if (!coin.getShortName().equals("BTC")) {
        //we create the URL for request the market
        String urlMarket = "https://bittrex.com/api/v1.1/public/getmarketsummary?market=btc-SHORTNAME";

        String coinShortName = coin.getShortName();

        urlMarket = urlMarket.replaceAll("SHORTNAME", coinShortName.toLowerCase());

        //once created the url, we create the request with JSONObject

        JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, urlMarket, null, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {

                try {

                    JSONArray result = response.getJSONArray("result");
                    //we loop the response
                    for (int i = 0; i < result.length(); i++) {
                        coin.setHigh(Double.parseDouble(result.getJSONObject(i).getString("High")));

                        coin.setLow(Double.parseDouble(result.getJSONObject(i).getString("Low")));
                        coin.setLast(Double.parseDouble(result.getJSONObject(i).getString("Last")));
                        coin.setVolInBtc(Double.parseDouble(result.getJSONObject(i).getString("BaseVolume")));
                        coin.setBid(Double.parseDouble(result.getJSONObject(i).getString("Bid")));
                        coin.setAsk(Double.parseDouble(result.getJSONObject(i).getString("Ask")));
                        coin.setPrevDay(result.getJSONObject(i).getString("PrevDay"));

                        listCoins.add(coin);
                        callback.onSuccess(listCoins);

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

            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                error.printStackTrace();
            }
        });

        requestQueue.add(request);
    }
}

return listCoins;
}

这是我初始化回调的方式（在发出请求之前）：

public void initCallback() {

this.coinCallback = new CoinCallback() {
    @Override
    public void onSuccess(ArrayList<Coin> coinListFromRequest) {
        coinList=coinListFromRequest;
    }
};
}

以下是我调用请求的方法（初始化回调后）：

coinList = bittrexAPIRequest.getMarketSummary(coinCallback, coinList, this);
adapter.notifyDataSetChanged();

最后，我的CoinCallback界面：

public interface CoinCallback {
void onSuccess(ArrayList<Coin> coinList);

}

Answer 1

错误getMarketSummary（）总是返回Empty list.so使getMarketSummary返回类型为void并传递CoinCallback接口中的列表。

  public void getMarketSummary(final DashboardActivity.CoinCallback callback, ArrayList<Coin> listAux, Context context) {

        Log.d("chegamos a entrar en getCOinData??", "Entramos en getMarketSummary");

        listCoins.clear();

        requestQueue = Volley.newRequestQueue(context);

        for (Coin coinAux : listAux) {
            this.coin = coinAux;

            if (!coin.getShortName().equals("BTC")) {
                //we create the URL for request the market
                String urlMarket = "https://bittrex.com/api/v1.1/public/getmarketsummary?market=btc-SHORTNAME";

                String coinShortName = coin.getShortName();

                urlMarket = urlMarket.replaceAll("SHORTNAME", coinShortName.toLowerCase());

                //once created the url, we create the request with JSONObject

                JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, urlMarket, null, new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {

                        try {

                            JSONArray result = response.getJSONArray("result");
                            //we loop the response
                            for (int i = 0; i < result.length(); i++) {
                                coin.setHigh(Double.parseDouble(result.getJSONObject(i).getString("High")));

                                coin.setLow(Double.parseDouble(result.getJSONObject(i).getString("Low")));
                                coin.setLast(Double.parseDouble(result.getJSONObject(i).getString("Last")));
                                coin.setVolInBtc(Double.parseDouble(result.getJSONObject(i).getString("BaseVolume")));
                                coin.setBid(Double.parseDouble(result.getJSONObject(i).getString("Bid")));
                                coin.setAsk(Double.parseDouble(result.getJSONObject(i).getString("Ask")));
                                coin.setPrevDay(result.getJSONObject(i).getString("PrevDay"));

                                listCoins.add(coin);


                            }
                           callback.onSuccess(listCoins);

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

                    }
                }, new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        error.printStackTrace();
                    }
                });

                requestQueue.add(request);
            }
        }

        //return listCoins;
        }

更新iniCallBack，现在更新的列表将在onSuccess中返回，您也可以在for中调用服务器，它可以多次调用相同的服务。

  public void initCallback() {
    coinList =new ArrayList();
    adapter =new Adapter(coinList);
    list.setAdapter(adapter);

    this.coinCallback = new CoinCallback() {
        @Override
        public void onSuccess(ArrayList<Coin> coinList) {
           coinList.addAll(coinList);
            adapter.notifyDataSetChanged();
        }
    };

    bittrexAPIRequest.getMarketSummary(coinCallback, coinList, this);
    }

我无法与JSON和Volley的请求共享数据到其他Android活动

1 个答案: