我正在一个片段中尝试更新我的可回收视图,在查询某些数据后。在查询的done
方法中,我调用了notifyDataSetChanged
,但列表从未显示。
package com.garciaericn.t2d.fragments;
public class DevicesCardViewFragment extends Fragment implements View.OnClickListener {
private OnFragmentInteractionListener mListener;
private BatteryHelper mBatteryHelper;
Intent mBatteryStatus;
private RecyclerView mRecyclerView;
private DeviceAdapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
private List<Device> mDevices;
public DevicesCardViewFragment() {
// Required empty public constructor
mDevices = new ArrayList<Device>();
}
public static DevicesCardViewFragment newInstance() {
// Bundle parameters is necessary
return new DevicesCardViewFragment();
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get arguments
getDevices();
mBatteryHelper = new BatteryHelper(getActivity());
IntentFilter intentFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
mBatteryStatus = getActivity().registerReceiver(null, intentFilter);
// Update stats of current device.
Toast.makeText(getActivity(), "Battery level: " + mBatteryHelper.getCurrentBatteryLevel() + "%", Toast.LENGTH_LONG).show();
// Update device stats
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_devices_list, container, false);
mListener.showAd();
// Obtain recycler view
mRecyclerView = (RecyclerView) view.findViewById(R.id.devices_recycler_view);
mRecyclerView.setHasFixedSize(true);
mAdapter = new DeviceAdapter(getActivity(), mDevices);
// Set adapter
mRecyclerView.setAdapter(mAdapter);
// Set layout manager
mLayoutManager = new LinearLayoutManager(getActivity());
mRecyclerView.setLayoutManager(mLayoutManager);
return view;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public List<Device> getDevices() {
ParseQuery<Device> query = ParseQuery.getQuery(Device.DEVICES);
// new ParseQuery<Device>(Device.DEVICES);
query.whereEqualTo("deviceUser", ParseUser.getCurrentUser());
query.findInBackground(new FindCallback<Device>() {
@Override
public void done(List<Device> devices, ParseException e) {
if (e == null) {
// Loop through return devices
for (Device device : devices) {
Device currentDevice = new Device();
currentDevice.setDeviceName(device.getDeviceName());
currentDevice.setBatteryLevel(device.getBatteryLevel());
currentDevice.setIsCharging(device.isCharging());
mDevices.add(currentDevice);
}
mAdapter.notifyDataSetChanged();
} else {
// Something went wrong
Toast.makeText(getActivity(), "Error: " + e.toString(), Toast.LENGTH_LONG).show();
}
}
});
return mDevices;
}
@Override
public void onClick(View v) {
// Click events go here
}
public static DevicesCardViewFragment newInstance(List<Device> mDevices) {
DevicesCardViewFragment fragment = new DevicesCardViewFragment();
Bundle args = new Bundle();
return fragment;
}
public interface OnFragmentInteractionListener {
public void showAd();
}
}
我的RecyclerView适配器如下所示:
package com.garciaericn.t2d.data;
public class DeviceAdapter extends RecyclerView.Adapter<DeviceAdapter.MyViewHolder> {
private final LayoutInflater inflater;
List<Device> data = Collections.emptyList();
public DeviceAdapter(Context context, List<Device> data) {
inflater = LayoutInflater.from(context);
this.data = data;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflater.inflate(R.layout.card_layout, parent, false);
MyViewHolder holder = new MyViewHolder(view);
return holder;
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
Device device = data.get(position);
holder.deviceNameTV.setText(device.getDeviceName());
holder.batteryLevelTV.setText(device.getBatteryLevel());
}
@Override
public int getItemCount() {
return 0;
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
// Temp data set
private String[] mDataset;
TextView deviceNameTV;
TextView batteryLevelTV;
public MyViewHolder(View itemView) {
super(itemView);
deviceNameTV = (TextView) itemView.findViewById(R.id.device_name_tv);
batteryLevelTV = (TextView) itemView.findViewById(R.id.battery_level_tv);
}
}
}