Question

我可以使用自定义适配器在gridview中正确显示图像（默认设置）。但是，当我尝试更改ForecastFragment（下面的代码段）中的字符串[]时，不会调用updateList函数。我希望重新创建网格中的所有视图。

ImageAdapter.java：

public class ImageAdapter extends BaseAdapter {
public Context mContext;   ImageAdapter(Context c) {
    mContext = c;
    String LOG_TAG = ImageAdapter.class.getSimpleName();
    Log.e(LOG_TAG,"Constructor Context  :  "+mContext);


}

public int getCount() {
    return this.eatFoodyImages.length;
}
public int size1;
public int size2;
public Object getItem(int position) {
    return null;
}

public long getItemId(int position) {
    return 0;
}

public void updateList(String[] string)
{
    this.eatFoodyImages=string;
    this.notifyDataSetChanged();
    String LOG_TAG = ImageAdapter.class.getSimpleName();
    Log.e(LOG_TAG, "\n\nupdatelist  :  " + this.eatFoodyImages);
}


// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {

    ImageView imageView;
    if (convertView == null) {
        // if it's not recycled, initialize some attributes
        imageView = new ImageView(mContext);
       size1 = (int) this.mContext.getResources().getDimension(R.dimen.image_size1);
       size2 = (int) this.mContext.getResources().getDimension(R.dimen.image_size2);

        imageView.setLayoutParams(new GridView.LayoutParams(size1,size2));
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setPadding(0, 0, 0, 0);

    } else {
        imageView = (ImageView) convertView;
    }
    String LOG_TAG = ImageAdapter.class.getSimpleName();
    Log.e(LOG_TAG, "\n\n\nPosition :  " + position + "   Strings Array : \n\n" + eatFoodyImages[position].toString());
    //System.out.println();

        Picasso.with(mContext)
                .

        load(eatFoodyImages[position])

                .

                into(imageView);


        return imageView;
    }


            // references to our images
    public String[] eatFoodyImages = {
        "http://i.imgur.com/rFLNqWI.jpg",               //Default Random Data!!!
        "http://i.imgur.com/C9pBVt7.jpg",
        "http://i.imgur.com/rT5vXE1.jpg",
        "http://i.imgur.com/aIy5R2k.jpg",
        "http://i.imgur.com/MoJs9pT.jpg",
        "http://i.imgur.com/S963yEM.jpg",
        "http://i.imgur.com/rLR2cyc.jpg",
        "http://i.imgur.com/SEPdUIx.jpg",
        "http://i.imgur.com/aC9OjaM.jpg",
        "http://i.imgur.com/76Jfv9b.jpg",
        "http://i.imgur.com/fUX7EIB.jpg",
        "http://i.imgur.com/syELajx.jpg",
        "http://i.imgur.com/COzBnru.jpg",
        "http://i.imgur.com/Z3QjilA.jpg",
  };
 }

ForecastFragment.java：

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

       View rootView = inflater.inflate(R.layout.fragment_main, container, false);

    GridView gridview = (GridView) rootView.findViewById(R.id.gridview);

    movieadapter = new ImageAdapter(this.getActivity());
    gridview.setAdapter(movieadapter);

    });

    return rootView;
}

调用updateList：

 public class FetchWeatherTask extends AsyncTask<String, Void, String[]>
{//Showing only relevant code

IA.updateList(eatFoodyImages); //Here eatFoodyImages contains the new String[] to be used for image loading.

Answer 1

在这里，我有一个像下面的适配器

public View getView(int position, View convertView, ViewGroup parent) {

        Movie movie = getItem(position);

        if (convertView == null) {
            convertView = LayoutInflater.from(getContext()).inflate(
                    R.layout.movie_tile, parent, false);
        }

        ImageView imageView = (ImageView) convertView.findViewById(R.id.movie_image);
        Picasso.with(this.getContext()).load(Constants.MOVIE_POSTER_PATH_SMALL + movie.getPosterPath()).placeholder(ContextCompat.getDrawable(this.getContext(), R.drawable.movie)).error(ContextCompat.getDrawable(this.getContext(), R.drawable.movie)).into(imageView);


        return convertView;
    }

在网格视图中设置图块。

我触发asynctask并从API获取电影然后通知加载电影的数据集并刷新视图。

基本上你的notifyDataSet（）应该在AsyncTask的onPostExecute（）中。

这是我的异步任务代码，以便更好地理解。

public class CallMovieDBAPI extends AsyncTask<String, Void, List<Movie>> {

        ProgressDialog dialog;
        private Activity activity;
        private GridView gridView;

        public CallMovieDBAPI(Activity activity, GridView gridView) {
            this.activity = activity;
            this.gridView = gridView;
        }

        @Override
        protected void onPreExecute() {
            dialog = new ProgressDialog(getActivity());
            dialog.setMessage(activity.getString(R.string.progressDialogText));
            dialog.show();
        }

        @Override
        protected List<Movie> doInBackground(String... params) {
            InputStream in = null;
            String jsonResponse = null;
            String apiURL = params[0];
            try {

                URL url = new URL(apiURL);

                HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
                in = new BufferedInputStream(urlConnection.getInputStream());
                jsonResponse = getJsonObject(in);
                movieList = JsonParser.parse(jsonResponse);

            } catch (Exception e) {

                Log.e("CallMovieDBAPI", "Exception occurred in AsyncTask - CallMovieDBAPI", e);
            }

            return movieList;


        }

        @Override
        protected void onPostExecute(List<Movie> movies) {
            Log.d("Popular Movies", "Got data successfully");
            if (dialog.isShowing()) {
                dialog.dismiss();
            }
            movieAdapter = new MovieAdapter(activity, movieList);
            gridView.setAdapter(movieAdapter);
            movieAdapter.notifyDataSetChanged();
            if (isTablet) {
                ((MovieClickedCallback) getActivity()).onMovieClicked(0, movieAdapter);
            }

        }

如果这解决了，请告诉我。

通过自定义适配器更新Gridview中的图像

1 个答案: