在为自定义ListAdapter Listview实现onClickListener时遇到麻烦

Question

我在为我的ListView实现onItemClick时遇到了麻烦。我需要在点击ListView中的项目时打开一个新活动，并将标题/类型/评级/发行年份数据传递给这个新活动。我还想知道如何通过ListView中单击的项目的缩略图图像并将其显示在新活动中。

CustomListAdapter.java

public class CustomListAdapter extends BaseAdapter {
    private Activity activity;
    private LayoutInflater inflater;
    private List<Movie> movieItems;
    ImageLoader imageLoader = AppController.getInstance().getImageLoader();
    public CustomListAdapter(Activity activity, List<Movie> movieItems) {
        this.activity = activity;
        this.movieItems = movieItems;
    }
    @Override
    public int getCount() {
        return movieItems.size();
    }
    @Override
    public Object getItem(int location) {
        return movieItems.get(location);
    }
    @Override
    public long getItemId(int position) {
        return position;
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (inflater == null)
            inflater = (LayoutInflater) activity
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        if (convertView == null)
            convertView = inflater.inflate(R.layout.list_row, null);
        if (imageLoader == null)
            imageLoader = AppController.getInstance().getImageLoader();
        NetworkImageView thumbNail = (NetworkImageView) convertView
                .findViewById(R.id.thumbnail);
        TextView title = (TextView) convertView.findViewById(R.id.title);
        TextView rating = (TextView) convertView.findViewById(R.id.rating);
        TextView genre = (TextView) convertView.findViewById(R.id.genre);
        TextView year = (TextView) convertView.findViewById(R.id.releaseYear);
        // getting movie data for the row
        Movie m = movieItems.get(position);
        // thumbnail image
        thumbNail.setImageUrl(m.getThumbnailUrl(), imageLoader);
        // title
        title.setText(m.getTitle());
        // rating
        rating.setText("Rating: " + String.valueOf(m.getRating()));
        // genre
        String genreStr = "";
        for (String str : m.getGenre()) {
            genreStr += str + ", ";
        }
        genreStr = genreStr.length() > 0 ? genreStr.substring(0,
                genreStr.length() - 2) : genreStr;
        genre.setText(genreStr);
        // release year
        year.setText(String.valueOf(m.getYear()));
        return convertView;
    }
}

Main2Activity.java

public class Main2Activity extends AppCompatActivity  {
    // Log tag
    private static final String TAG = Main2Activity.class.getSimpleName();
    // Movies json url
    private static final String url = "http://api.androidhive.info/json/movies.json";
    private ProgressDialog pDialog;
    private List<Movie> movieList = new ArrayList<Movie>();
    private ListView listView;
    private CustomListAdapter adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        listView = (ListView) findViewById(service_list);
        adapter = new CustomListAdapter(this, movieList);
        listView.setAdapter(adapter);

        pDialog = new ProgressDialog(this);
        // Showing progress dialog before making http request
        pDialog.setMessage("Loading...");
        pDialog.show();
        // changing action bar color
        //getActionBar().setBackgroundDrawable(
                //new ColorDrawable(Color.parseColor("#1b1b1b")));
        // Creating volley request obj
        JsonArrayRequest movieReq = new JsonArrayRequest(url,
                new Response.Listener<JSONArray>() {
                    @Override
                    public void onResponse(JSONArray response) {
                        Log.d(TAG, response.toString());
                        hidePDialog();
                        // Parsing json
                        for (int i = 0; i < response.length(); i++) {
                            try {
                                JSONObject obj = response.getJSONObject(i);
                                Movie movie = new Movie();
                                movie.setTitle(obj.getString("title"));
                                movie.setThumbnailUrl(obj.getString("image"));
                                movie.setRating(((Number) obj.get("rating"))
                                        .doubleValue());
                                movie.setYear(obj.getInt("releaseYear"));
                                // Genre is json array
                                JSONArray genreArry = obj.getJSONArray("genre");
                                ArrayList<String> genre = new ArrayList<String>();
                                for (int j = 0; j < genreArry.length(); j++) {
                                    genre.add((String) genreArry.get(j));
                                }
                                movie.setGenre(genre);
                                // adding movie to movies array
                                movieList.add(movie);
                            } catch (JSONException e) {
                                e.printStackTrace();
                            }
                        }
                        // notifying list adapter about data changes
                        // so that it renders the list view with updated data
                        adapter.notifyDataSetChanged();
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                VolleyLog.d(TAG, "Error: " + error.getMessage());
                hidePDialog();
            }
        });
        // Adding request to request queue
        AppController.getInstance().addToRequestQueue(movieReq);
    }
    @Override
    public void onDestroy() {
        super.onDestroy();
        hidePDialog();
    }
    private void hidePDialog() {
        if (pDialog != null) {
            pDialog.dismiss();
            pDialog = null;
        }
    }
}

Answer 1

您可以发送整个对象movieItem和项目的位置点击然后在下一个活动中，您可以像这样提取它们

 listview.setOnItemClickListener(new OnItemClickListener(){
            @Override
            public void onItemClick(AdapterView<?> p1, View p2, int p3, long p4)
            {
                intent=new Intent(getBaseContext(),NextActivity.class);
            intent.putParcelableArrayListExtra("key", movielist);
intent.putExtra("IntKey",p3);
            }
        });

Answer 2

你可以将模型调用中的单个项作为Extras添加到意图中，或者你可以让模型类实现Serializable接口，然后手动将整个对象添加到意图中:

listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            Movie movie = (Movie) adapterView.getItemAtPosition(i);
            Intent intent = new Intent(view.getContext(), DetailActivity.class);
            intent.putExtra("mName", movie.getTitle());
            intent.putExtra("mRating", movie.getRating());
            intent.putExtra("mGenre", movie.getGenre());
            intent.putExtra("mYear". movie.getYear());
            //Get the Bitmap object from the NetworkImageView
            Bitmap bm = ((BitmapDrawable)((NetworkImageView)view.findViewById(R.id.image)).getDrawable()).getBitmap();
            //Can be added directly as an Extra, as Bitmap implements Parcelable
            intent.putExtra("mImage", bm);
            //OR make Moview implement Serializable and do this :
            //intent.putExtra("clickedObject", movie);
            startActivity(intent);
        }
    });

在接收活动中，您可以使用getExtras()来获取值:

Bitmap bm = getIntent().getExtras().getParcelable("mImage");
imageView.setImageBitmap(bm);

Answer 3

一切都很好，在回答这个问题的人的帮助下我修改了代码。

listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            Movie movie = (Movie) adapterView.getItemAtPosition(i);
            Intent intent = new Intent(view.getContext(), Main3Activity.class);
            intent.putExtra("mName", movie.getTitle());
            intent.putExtra("mRating", movie.getRating());
            intent.putExtra("mGenre", movie.getGenre());
            intent.putExtra("mYear", movie.getYear());
            intent.putExtra("mServiceImage",movie.getThumbnailUrl());
            //OR make Moview implement Serializable and do this :
            //intent.putExtra("clickedObject", movie);
            startActivity(intent);
        }
    });

在最后一个活动中，我使用Android-Universal-Image-Loader从第一个活动传递的url中加载图像。

  String mName = getIntent().getExtras().getString("mServiceImage");
  imageLoader.displayImage(mName, imageView);