在我从网络调用设置所有数据后添加模型时，不确定为什么列表为空。
如果我使用finalHourList，如果我打印到logcat，数据会显示在日志中。我不能使用finalHourList，因为我已将它绑定到适配器内的HourlyForcast模型。所以，我不能将适配器传递给一个字符串，并且必须将它传递给List。在将数据设置为预测后，不确定为什么finalHourList.add(forecast);为空。
硬编码列表没有任何问题，但现在我尝试使用从网络调用返回的数据填充RecyclerView。
public class HomeRecyclerAdapter extends RecyclerView.Adapter<HomeRecyclerAdapter.ViewHolder> {
private ArrayList<String> dates;
private Context context;
private String defaultZipcode = "55372";
private String mEnglishTemp, mCivilTime, mCondtion, mConditionIcon;
private List<HourlyForcast> finalHourlyList = new ArrayList<>();
HourlyForcastAdapter adapter;
private HourlyForcast forecast;
public HomeRecyclerAdapter(ArrayList<String> dates) {
this.dates = dates;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int i) {
context = parent.getContext();
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.hourly_cardview, parent, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
Typeface titleStyle = Typeface.createFromAsset(context.getAssets(),
"font/Roboto-Medium.ttf");
holder.mDate.setTypeface(titleStyle);
holder.mDate.setText(dates.get(position));
getHourlyWeather(defaultZipcode);
GridLayoutManager gridLayoutManager = new GridLayoutManager(context, 4);
holder.mInnerRecycler.setHasFixedSize(true);
holder.mInnerRecycler.setLayoutManager(gridLayoutManager);
adapter = new HourlyForcastAdapter(context, finalHourlyList);
holder.mInnerRecycler.setAdapter(adapter);
}
@Override
public int getItemCount() {
return dates.size();
}
public static class ViewHolder extends RecyclerView.ViewHolder {
private TextView mDate;
private RecyclerView mInnerRecycler;
ViewHolder(View view) {
super(view);
mDate = (TextView) view.findViewById(R.id.tvDate);
mInnerRecycler = (RecyclerView) view.findViewById(R.id.hourlyRecycler);
}
}
private List<HourlyForcast> getAllItemList() {
List<HourlyForcast> allHours = new ArrayList<>();
allHours.add(new HourlyForcast("4:00 PM", "8°", "Overcast"));
allHours.add(new HourlyForcast("5:00 PM", "6°", "Sunny"));
allHours.add(new HourlyForcast("6:00 PM", "5°", "Sunny"));
allHours.add(new HourlyForcast("7:00 PM", "3°", "Rainy"));
allHours.add(new HourlyForcast("8:00 PM", "3°", "Sunny"));
allHours.add(new HourlyForcast("9:00 PM", "3°", "Snowing"));
allHours.add(new HourlyForcast("10:00 PM", "4°", "Sunny"));
allHours.add(new HourlyForcast("11:00 PM", "60°", "Sunny"));
return allHours;
}
public void getHourlyWeather(String zipCode) {
OkHttpClient client = new OkHttpClient();
HttpUrl.Builder urlBuilder = HttpUrl.parse(context.getString
(R.string.hourlyForcastURL)).newBuilder();
urlBuilder.addPathSegment(zipCode + ".json");
String url = urlBuilder.build().toString();
Request request = new Request.Builder()
.url(url)
.build();
client.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
e.printStackTrace();
call.cancel();
}
@Override
public void onResponse(Call call, Response response) throws IOException {
String mResponse = response.body().string();
try {
JSONObject hourlyObject = new JSONObject(mResponse);
JSONArray hourForcastArray = hourlyObject.getJSONArray("hourly_forecast");
for (int i = 0; i < hourForcastArray.length(); i++) {
JSONObject HourlyObject = hourForcastArray.getJSONObject(i);
JSONObject mTemp = HourlyObject.getJSONObject("temp");
mConditionIcon = HourlyObject.getString("icon_url");
mEnglishTemp = mTemp.getString("english");
mCondtion = HourlyObject.getString("condition");
JSONObject FCTRemoveal = HourlyObject.getJSONObject("FCTTIME");
mCivilTime = FCTRemoveal.getString("civil");
forecast = new HourlyForcast();
forecast.setTime(mCivilTime);
forecast.setCondition(mCondtion);
forecast.setDegrees(mEnglishTemp);
/*finalHourlyList = new ArrayList<>();
finalHourlyList.add(mEnglishTemp);
finalHourlyList.add(mCivilTime);
finalHourlyList.add(mCondtion);*/
finalHourlyList = new ArrayList<>();
finalHourlyList.add(forecast);
Log.i("HOURLYLIST", finalHourlyList.toString());
}
} catch (JSONException e) {
e.printStackTrace();
}
}
});
}
}
适配器我将列表传递给
public class HourlyForcastAdapter extends RecyclerView.Adapter<HourlyForcastAdapter.HourlyViewHolder> {
private List<HourlyForcast> itemList;
private Context context;
public HourlyForcastAdapter(Context context, List<HourlyForcast> itemList) {
this.itemList = itemList;
this.context = context;
}
@Override
public HourlyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.hourly_single, parent, false);
return new HourlyViewHolder(view);
}
@Override
public void onBindViewHolder(HourlyViewHolder holder, int position) {
Typeface regStyle = Typeface.createFromAsset(context.getAssets(),
"font/Roboto-Regular.ttf");
holder.mTimeText.setTypeface(regStyle);
holder.mDegreeText.setTypeface(regStyle);
holder.mTimeText.setText(itemList.get(position).getTime());
holder.mDegreeText.setText(itemList.get(position).getDegrees());
holder.mWeatherIcon.setText(itemList.get(position).getCondition());
// holder.mWeatherIcon.setImageResource(itemList.get(position).getImageID());
}
@Override
public int getItemCount() {
return itemList.size();
}
public static class HourlyViewHolder extends RecyclerView.ViewHolder {
TextView mTimeText, mDegreeText, mWeatherIcon;
// ImageView mWeatherIcon;
public HourlyViewHolder(View itemView) {
super(itemView);
mTimeText = (TextView) itemView.findViewById(R.id.timePlaceHolder);
mDegreeText = (TextView) itemView.findViewById(R.id.degreePlaceHolder);
mWeatherIcon = (TextView) itemView.findViewById(R.id.weatherIconHolder);
}
}
}
答案 0 :(得分：1)
不要在适配器内部进行网络调用，而是将其放在您调用HomeRecyclerAdapter的类中，并将其命名为MainActivity。并在HomeRecyclerAdapter的构造函数中传递List。
在MainActivity中
final RecyclerView.Adapter adapter = new HomeRecyclerAdapter（days，finalHourlyList）;
getHourlyWeather（String zipCode）
在HomeRecyclerAdapter中
public HomeRecyclerAdapter(ArrayList<String> dates,ArrayList<HourlyForcast> finalHourlyList) {
this.dates = dates;
this.finalHourlyList = finalHourlyList;
}
答案 1 :(得分：0)
HourlyForcastAdapter adapter = new HourlyForcastAdapter(context, finalHourlyList); //passing this list to adapter
该行传递一个空引用，当前没有数据。因此，你最初是空的，所以你得到一些空的东西。要解决此问题，请在接受finalHourlyList的下一个适配器类中添加一个方法。然后，当网络呼叫完成后，手动调用此方法，从而传递新更新的列表。
同样在下一个适配器中，调用notifyDataSetChange以发出刷新信号。
adapter.notifyDataSetChanged();
有意义吗？ 主要原因是因为回收器在连接适配器时急切地显示数据。但是没有数据，所以它吓坏了。
将private List<HourlyForcast> finalHourlyList;更改为
private List<HourlyForcast> finalHourlyList = new ArrayList<>();
在最顶端。
---------------------------------------------------------------------
forecast = new HourlyForcast();
forecast.setTime(mCivilTime);
forecast.setCondition(mCondtion);
forecast.setDegrees(mEnglishTemp);
/*finalHourlyList = new ArrayList<>();
finalHourlyList.add(mEnglishTemp);
finalHourlyList.add(mCivilTime);
finalHourlyList.add(mCondtion);*/
finalHourlyList = new ArrayList<>();
finalHourlyList.add(forecast);
下面的这一行将起作用，因为它目前填充了数据。但我所说的是，当你在onBind adapter = new HourlyForcastAdapter(context, finalHourlyList);中调用此行时，还没有数据。你在想什么是这个，因为我在做出任何改变之前设置数据会自动反映，但不会。您必须触发更新并让回收者视图知道有新内容可用。因此您需要更新内部回收器视图适配器。模仿这种逻辑。
holder.mInnerRecycler. adapter.notifyDataSetChanged();