android - 如何使用 Json(类别和子类别)在 Android fragment 中显示 GridView 图像

Question

那些是类别和子类别。可以有或没有子类别。使用的JsonCode如下。

categoryId 将更改为调用子类别。例如。如果你想查看汽车的子类别

Json 代码

[{"Id":1,"TitleEN":"Cars","TitleAR":"سيارات","Photo":"http://souq.hardtask.co//Files/CategoryPhotos/ce686544-9f51-4213-b5db-7c015b788e8d.png","ProductCount":"3","HaveModel":"0","SubCategories":[{"Id":6,"TitleEN":"Cat6","TitleAR":"قسم6","Photo":"http://souq.hardtask.co//Files/CategoryPhotos/ce686544-9f51-4213-b5db-7c015b788e8d.png","ProductCount":"3","HaveModel":"0","SubCategories":[]}]},{"Id":2,"TitleEN":"Cat2","TitleAR":"قسم2","Photo":"http://souq.hardtask.co//Images/no_image.png","ProductCount":"8","HaveModel":"0","SubCategories":[{"Id":13,"TitleEN":"cat1 -1 ","TitleAR":"cat1 - 1","Photo":"http://souq.hardtask.co//Images/no_image.png","ProductCount":"8","HaveModel":"0","SubCategories":[]}]},{"Id":3,"TitleEN":"Cat3","TitleAR":"قسم3","Photo":"http://souq.hardtask.co//Images/no_image.png","ProductCount":"2","HaveModel":"0","SubCategories":[]},{"Id":4,"TitleEN":"Cat4","TitleAR":"قسم4","Photo":"http://souq.hardtask.co//Images/no_image.png","ProductCount":"1","HaveModel":"0","SubCategories":[]},{"Id":5,"TitleEN":"Cat5","TitleAR":"قسم5","Photo":"http://souq.hardtask.co//Images/no_image.png","ProductCount":"0","HaveModel":"0","SubCategories":[]},{"Id":8,"TitleEN":"Cat8","TitleAR":"قسم8","Photo":"http://souq.hardtask.co//Images/no_image.png","ProductCount":"0","HaveModel":"0","SubCategories":[]},{"Id":9,"TitleEN":"Slide01","TitleAR":"Slide02","Photo":"http://souq.hardtask.co//Files/CategoryPhotos/2ba07cb2-49a0-47e4-aba6-ef10a916fb12.png","ProductCount":"0","HaveModel":"0","SubCategories":[]}]

ImageAdapter

public class ImageAdapter extends BaseAdapter {
    private Context mContext;

    public ImageAdapter(Context c){
        mContext = c;
    }

    @Override
    public int getCount(){
        return images.size();
    }

    @Override
    public Object getItem(int position){
        return images.get(position);
    }

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

    public View getView(int position, View convertView, ViewGroup parent){
        ImageView imageview;
        if (convertView == null){
            imageview = new ImageView(mContext);
            imageview.setPadding(0, 0, 0, 0);
            //imageview.setLayoutParams(new GridLayout.MarginLayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
            imageview.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
            imageview.setAdjustViewBounds(true);
        } else {
            imageview = (ImageView) convertView;
        }

        Picasso.with(mContext).load(images.get(position)).placeholder(R.mipmap.ic_launcher).into(imageview);
        return imageview;
    }

    /*
    Custom methods
     */
    public void addItem(String url){
        images.add(url);
    }

    public void clearItems() {
        images.clear();
    }

    public ArrayList<String> images = new ArrayList<String>();
}

电影模特

public class Movie implements Parcelable {
    public String TitleEN;
    public String TitleAR;
    public String Photo;
    public int id;

    public Movie(){

    }

    protected Movie(Parcel in) {
        TitleEN = in.readString();
        TitleAR = in.readString();
        Photo = in.readString();
        id = in.readInt();
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(TitleEN);
        dest.writeString(TitleAR);
        dest.writeString(Photo);
        dest.writeInt(id);
    }

    @SuppressWarnings("unused")
    public static final Parcelable.Creator<Movie> CREATOR = new Parcelable.Creator<Movie>() {
        @Override
        public Movie createFromParcel(Parcel in) {
            return new Movie(in);
        }

        @Override
        public Movie[] newArray(int size) {
            return new Movie[size];
        }
    };
}

Fragament_main

    public class Fragament_main extends Fragment {


        public View mainFragmentView;
        public String LOG_TAG = "ShowcaseFragment";
        public ArrayList<Movie> movies = new ArrayList<Movie>();
        private RequestQueue mRequestQueue;
        public ImageAdapter imageAdapter;
        public static Fragament_main instance;
        GridView gridview;
        public boolean isDualPane = false;

        // static to preserve sorting over orientation changes (activity restart)
        public static String sortOrder = "popularity.desc", moreParams = "";
        public static boolean setting_cached = false;
        public int gridPos = -1;

        public Fragament_main() {
            // Required empty public constructor

            instance = this;


        }




     @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            mainFragmentView = inflater.inflate(R.layout.fragment_main, container, false);
            mRequestQueue = Volley.newRequestQueue(getContext());

            // setup adapters
            imageAdapter = new ImageAdapter(getContext());
            gridview = (GridView) mainFragmentView.findViewById(R.id.gridView);
            gridview.setAdapter(imageAdapter);

            //updateUI(setting_cached);
            //gridview.setOnItemClickListener(new GridClickListener());
            // manage grid col count wrt Orientation
            if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE)
                setGridColCount(3);
            else
                setGridColCount(2);

            return mainFragmentView;
        }

        @Override
        public void onActivityCreated(Bundle savedInstanceState) {
            super.onActivityCreated(savedInstanceState);

        }

        @Override
        public void onSaveInstanceState(Bundle outState) {
            super.onSaveInstanceState(outState);
            outState.putInt("GRIDVIEW_POSITION", gridview.getFirstVisiblePosition());
        }

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            if (savedInstanceState != null)
                gridPos = savedInstanceState.getInt("GRIDVIEW_POSITION");
        }

        @Override
        public void onDestroyView() {
            super.onDestroyView();
            mRequestQueue.cancelAll(new RequestQueue.RequestFilter() {
                @Override
                public boolean apply(Request<?> request) {
                    return true;
                }
            });
        }

        /*class GridClickListener implements AdapterView.OnItemClickListener {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
                if (isDualPane){
                    android.support.v4.app.FragmentTransaction ft = getActivity().getSupportFragmentManager().beginTransaction();
                    DetailActivityFragment detailActivityFragment = DetailActivityFragment.newInstance(movies.get(position));
                    ft.replace(R.id.detailContainer, detailActivityFragment);
                    ft.commit();
                } else {
                    Intent intent = new Intent(getContext(), DetailActivity.class);
                    intent.putExtra(Intent.EXTRA_TEXT, (Parcelable) movies.get(position));
                    startActivity(intent);
                }
            }
        }*/

      /*  public void updateUI(boolean cached){
            movies.clear();
            imageAdapter.clearItems();
            setting_cached = cached;
            if (!cached)
                getMovies(sortOrder, moreParams);
            else
                getFavorites();
        }
    */
        public void getMovies(String sortOrder, String moreParams){
            String url = "http://souq.hardtask.co/app/app.asmx/GetCategories?categoryId=0&countryId=1";
            JsonObjectRequest req = new JsonObjectRequest(url, null,
                    new Response.Listener<JSONObject>() {
                        @Override
                        public void onResponse(JSONObject response) {
                            try {
                                JSONArray items = response.getJSONArray("results");
                                JSONObject movieObj;
                                for (int i=0; i<items.length(); i++){
                                    movieObj = items.getJSONObject(i);
                                    Movie movie = new Movie();
                                    movie.id = movieObj.getInt("id");
                                    movie.TitleEN = movieObj.getString("original_title");
                                    movie.TitleAR = movieObj.getString("overview");
                                    movie.Photo = "http://souq.hardtask.co/app/app.asmx/GetCategories?categoryId=0&countryId=1" + movieObj.getString("poster_path");
                                    movies.add(movie);
                                    // Add image to adapter
                                    imageAdapter.addItem(movie.Photo);
                                }
                            } catch (JSONException e){
                                e.printStackTrace();
                            }
                            getActivity().runOnUiThread(new Runnable() {
                                @Override
                                public void run() {
                                    gridview.setAdapter(imageAdapter);
                                    if (gridPos > -1)
                                        gridview.setSelection(gridPos);
                                    gridPos = -1;
                                }
                            });
                        }
                    }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Log.d(LOG_TAG, "Error in JSON Parsing");
                }
            });

            mRequestQueue.add(req);
        }

       /* public void getFavorites(){
            movies.addAll((new MoviesDB()).getFavoriteMovies(getContext().getContentResolver()));
            for (Movie movie : movies){
                imageAdapter.addItem(movie.Photo);
            }
            gridview.setAdapter(imageAdapter);
            if (gridPos > -1)
                gridview.setSelection(gridPos);
            gridPos = -1;
        }*/

        public void updateFavoritesGrid(){
            if (setting_cached) {
                int p = gridview.getLastVisiblePosition();
                ///updateUI(true);
                gridview.smoothScrollToPosition(p);
            }
        }

        public void setGridColCount(int n){
            ((GridView) mainFragmentView.findViewById(R.id.gridView)).setNumColumns(n);
        }


    }

我不知道如何将Json 数据添加到GridView 中。你能帮帮我吗？

Answer 1

通过this example在网格中查看图像，通过使用将您的 jsonArray 转换为 ArrayList，

ArrayList<Cars> carsList = new Gson().fromJson(jsonArrayYouHave.toString(),new TypeToken<List<Cars>>() {
        }.getType());

将此数组传递给您的适配器。

使用这个 POJO，

    public class Cars {
    private String TitleAR;

    private String HaveModel;

    private String TitleEN;

    private String Id;

    private ArrayList<SubCategories> SubCategories;

    private String Photo;

    private String ProductCount;

    //Todo please add getter/setters for class Cars variables here

    public class SubCategories {
        private String TitleAR;

        private String HaveModel;

        private String TitleEN;

        private String Id;

        private ArrayList<String> SubCategories;

        private String Photo;

        private String ProductCount;

        //Todo please add getter/setters for class SubCategories variables here
    }

我建议使用 Retrofit，因为它会为您提供已解析的数组列表，该数组列表会转换为您提供的 Response POJO。您可以找到许多关于Retrofit 的示例。