填充 RecyclerView 列表

Question

我似乎无法让我的 RecyclerView 一直填充。它只制作第一个单元格，其他的都是空白的。即使 for 循环似乎运行多次。

    JsonObjectRequest root = new JsonObjectRequest(Request.Method.GET, URL, null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            try {
                JSONObject feed = response.getJSONObject("feed");
                JSONArray results = feed.getJSONArray("results");
                //Log.d("FEED", String.valueOf(feed));w
                for(int i = 0; i<results.length(); i++){
                    JSONObject resultsObj = results.getJSONObject(i);

                    Log.d(TAG, "inside" + String.valueOf(i));
                    mImageUrls.add(resultsObj.getString("artworkUrl100"));
                    mTitle.add(resultsObj.getString("name"));
                    getRecyclerView();
                }

                adapter.notifyDataSetChanged();

            } catch (JSONException e) {
                e.printStackTrace();
            }

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {

        }
    });
    mRequestQueue.add(root);

}

private void getRecyclerView(){
    Log.d(TAG, "getRecyclerView");
    recyclerView = findViewById(R.id.recyclerView);
    adapter = new RecyclerViewAdapter(mImageUrls, mTitle, this);
    recyclerView.setAdapter(adapter);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setHasFixedSize(true);
}

Answer 1

告诉我这是否有效：

JsonObjectRequest root = new JsonObjectRequest(Request.Method.GET, URL, null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            try {
                JSONObject feed = response.getJSONObject("feed");
                JSONArray results = feed.getJSONArray("results");
                //Log.d("FEED", String.valueOf(feed));w
                for(int i = 0; i<results.length(); i++){
                    JSONObject resultsObj = results.getJSONObject(i);

                    Log.d(TAG, "inside" + String.valueOf(i));
                    mImageUrls.add(resultsObj.getString("artworkUrl100"));
                    mTitle.add(resultsObj.getString("name"));
                }

                getRecyclerView();
                adapter.notifyDataSetChanged();

            } catch (JSONException e) {
                e.printStackTrace();
            }

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {

        }
    });
    mRequestQueue.add(root);

}

private void getRecyclerView(){
    Log.d(TAG, "getRecyclerView");
    recyclerView = findViewById(R.id.recyclerView);
    adapter = new RecyclerViewAdapter(mImageUrls, mTitle, this);
    recyclerView.setAdapter(adapter);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setHasFixedSize(true); }

我做的是getRecyclerView();移到循环外，因为你只需要调用它一次，而不是每次你想设置recyclerview。

Answer 2

每次用一个值初始化适配器。这就是为什么列表包含一个值而其他值是空白的原因。您需要将 getRecyclerView(); 移到循环外。

看起来像这样：

try {
            JSONObject feed = response.getJSONObject("feed");
            JSONArray results = feed.getJSONArray("results");
            //Log.d("FEED", String.valueOf(feed));w
            for(int i = 0; i<results.length(); i++){
                JSONObject resultsObj = results.getJSONObject(i);

                Log.d(TAG, "inside" + String.valueOf(i));
                mImageUrls.add(resultsObj.getString("artworkUrl100"));
                mTitle.add(resultsObj.getString("name"));

            }
             getRecyclerView();
           // No need to notify the data set changed 
           // adapter.notifyDataSetChanged();

        } catch (JSONException e) {
            e.printStackTrace();
        }

Answer 3

使用这个可能对你有帮助。

private void getRecyclerView(){
    Log.d(TAG, "getRecyclerView");
    recyclerView = findViewById(R.id.recyclerView);
    adapter = new RecyclerViewAdapter(mImageUrls, mTitle, this);
    recyclerView.setAdapter(adapter);
    recyclerView.setLayoutManager(new LinearLayoutManager(this, 
    LinearLayoutManager.VERTICAL, false));
    recyclerView.setHasFixedSize(true);
}

填充 RecyclerView 列表

Populate the RecyclerView List

java

android

android-adapter

android-recyclerview