RecyclerView 覆盖列表项

Question

我正在开发任务管理器应用程序。基本上 google 地方 api 我选择位置将其保存到 sqlite 数据库并将其填充到 RecyclerView 中。对于每个位置，我使用 retrofit2 和 openweather api 来获取该位置的当前天气并将其显示在 RecyclerView 中。这是在位于 onBindViewHolder 方法中的 recyclerview 适配器中的异步任务中完成的。现在，当我创建一个任务时，它可以毫无问题地将数据获取到该位置。当我添加更多任务时，问题就开始了。基本上，当我在新位置添加新任务时，它会覆盖上次添加任务的当前天气，如下图所示。

https://s9.postimg.org/l6tmi3wm7/Screenshot_20160830_143608.png

我怎样才能让它不覆盖以前的任务？

public class TaskAdapter extends RecyclerView.Adapter<TaskAdapter.ViewHolder> {

    private List<Task> taskList;

    private final String API_KEY = "8617b30a6fc114ad2ad929c111b76edf";
    private final String UNITS = "metric";
    private double latitude, longitude;
    private Task task;
    private WeatherInfo weatherInfo;
    private Context context;

    public class ViewHolder extends RecyclerView.ViewHolder {
        private TextView taskName, destination, currentWeather;

        private ImageView weatherImg;

        public ViewHolder(View view) {
            super(view);
            taskName = (TextView) view.findViewById(R.id.task);
            destination = (TextView) view.findViewById(R.id.date);
            currentWeather = (TextView) view.findViewById(R.id.weather);
            weatherImg = (ImageView) view.findViewById(R.id.weather_icon);
        }
    }

    public TaskAdapter(List<Task> taskList) {
        this.taskList = taskList;
    }

    public void add(int position, Task item) {
        taskList.add(position, item);
        notifyItemInserted(position);
    }

    public void remove(Task item) {
        int position = taskList.indexOf(item);
        taskList.remove(position);
        notifyItemRemoved(position);
    }

    public Task getTask(int position) {
        return taskList.get(position);
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        context = parent.getContext();
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_rv, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        task = taskList.get(position);
        latitude = task.getDestinationLatitude();
        longitude = task.getDestinationLongitude();


        new getWeatherDataAsync(holder).execute();


        holder.taskName.setText(task.getTaskName());
        holder.destination.setText(task.getDestinationName());
    }

    @Override
    public int getItemCount() {
        return taskList.size();
    }

    private class getWeatherDataAsync extends AsyncTask<Void, Void, Void> {

        private ViewHolder holder;
        private ProgressDialog progressDialog;

        public getWeatherDataAsync(ViewHolder holder) {
            this.holder = holder;
        }

        @Override
        protected void onPreExecute() {
            progressDialog=ProgressDialog.show(context,"Loading...","Getting weather.");
        }

        @Override
        protected Void doInBackground(Void... vHolders) {
            try {

                WeatherApi weatherApi = WeatherApi.retrofit.create(WeatherApi.class);
                Call<WeatherInfo> call = weatherApi.getWeatherData(latitude, longitude, API_KEY, UNITS);
                weatherInfo = call.execute().body();

//
            } catch (IOException e) {
                Log.e("get weather coordinates", "something went wrong: " + e.getMessage());
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);

            if (weatherInfo != null) {
                holder.currentWeather.setText(String.valueOf(weatherInfo.getMain().getTemp()) + "\u2103");
                getWeatherIcon(holder);

            } else {
                holder.currentWeather.setText("N/A \u2103");
                Picasso.with(context).load("file:///android_asset/md-weather-iconset/weather-none-available.png").into(holder.weatherImg);
            }


            progressDialog.dismiss();

        }

    }

    /**
     * Display the correct weather icon from assets based on the data returned from the Retrofit query.
     * @param viewHolder
     */
    private void getWeatherIcon(ViewHolder viewHolder){
         String base="file:///android_asset/md-weather-iconset";



        switch (weatherInfo.getWeather().get(0).getIcon()) {
            case "01d":
                Picasso.with(context).load(base+"/weather-clear.png").into(viewHolder.weatherImg);
                break;
            case "02d":
                Picasso.with(context).load(base+"/weather-few-clouds.png").into(viewHolder.weatherImg);
                break;
            case "03d":
                Picasso.with(context).load(base+"/weather-clouds.png").into(viewHolder.weatherImg);
                break;
            case "04d":
                Picasso.with(context).load(base+"/weather-clouds.png").into(viewHolder.weatherImg);
                break;
            case "09d":
                Picasso.with(context).load(base+"/weather-showers-day.png").into(viewHolder.weatherImg);
                break;
            case "10d":
                Picasso.with(context).load(base+"/weather-rain-day.png").into(viewHolder.weatherImg);
                break;
            case "11d":
                Picasso.with(context).load(base+"/weather-storm-day.png").into(viewHolder.weatherImg);
                break;
            case "13d":
                Picasso.with(context).load(base+"/weather-snow.png").into(viewHolder.weatherImg);
                break;
            case "50d":
                Picasso.with(context).load(base+"/weather-mist.png").into(viewHolder.weatherImg);
                break;
            case "01n":
                Picasso.with(context).load(base+"/weather-clear-night.png").into(viewHolder.weatherImg);
                break;
            case "02n":
                Picasso.with(context).load(base+"/weather-few-clouds-night.png").into(viewHolder.weatherImg);
                break;
            case "03n":
                Picasso.with(context).load(base+"/weather-clouds-night.png").into(viewHolder.weatherImg);
                break;
            case "04n":
                Picasso.with(context).load(base+"/weather-clouds-night.png").into(viewHolder.weatherImg);
                break;
            case "09n":
                Picasso.with(context).load(base+"/weather-showers-night.png").into(viewHolder.weatherImg);
                break;
            case "10n":
                Picasso.with(context).load(base+"/weather-rain-night.png").into(viewHolder.weatherImg);
                break;
            case "11n":
                Picasso.with(context).load(base+"/weather-storm-night.png").into(viewHolder.weatherImg);
                break;
            case "13n":
                Picasso.with(context).load(base+"/weather-snow.png").into(viewHolder.weatherImg);
                break;
            case "50n":
                Picasso.with(context).load(base+"/weather-mist.png").into(viewHolder.weatherImg);
                break;


        }
    }


}

Answer 1

首先你能说清楚你的预期输出是什么吗？也许显示您的预期输出和您获得的输出的图像就足够了。我还建议您不要从适配器内部的网络获取，而是获取片段中的所有天气数据并将信息传递给 adapter.Lets 假设您有一个 Activity 持有 recyclerview。使用接口从适配器调用异步任务。

同时将纬度和经度存储在 viewholder 中，然后再次尝试查看是否有效。

Answer 2

您正在使用 onBindViewHolder() 启动异步任务并将对 holder 的引用传递给它。不幸的是，这不是 RecyclerView 应该工作的方式。 RecyclerView 使用 ViewHolder 模式重用已实例化但不再可见的布局，这就是为什么 holder 在网络响应启动时可能代表完全不同的项目。

您应该做的是将调用异步调用移动到其他地方（例如 Fragment/Activity/Presenter），从回调中更新您的 taskList 集合并使用以下方法之一通知适配器数据集已更改：

notifyDataSetChanged()

notifyItemInserted()

看看 RecyclerView.Adapter 文档：

ReyclerView.Adapter

Answer 3

问题是

private WeatherInfo weatherInfo;

在 AsyncTask 中创建 WeatherInfo 对象。这将解决您的问题。 AsyncTask 被执行，它将创建新的 WeatherInfo 对象。现在将该对象传递给方法 so。

像这样改变方法

getWeatherIcon(ViewHolder viewHolder,WeatherInfo  wetherInfo)

这将解决您的问题。

RecyclerView 覆盖列表项

RecyclerView overwriting list items

android

picasso

android-recyclerview

retrofit2

openweathermap