Recycleview 不从 json url 加载图像

Question

我确实面临一个奇怪的问题。我正在关注来自此链接https://github.com/SaurabhKukreja/MyRecyclerViewExample 的教程，他使用 Recycleview 从 json 加载图像。

在 Homefragment 中，他使用了具有以下结构的 url json

[{
    "name": "Tom Hardy",
    "image": "https://api.androidhive.info/json/images/tom_hardy.jpg",
    "phone": "(541) 754-3010"
},

当应用程序被编译时..图像成功加载。但是现在当我用我自己在 00webhost 中托管的图像替换图像 url 时，图像不会加载。

这是来自我的主机帐户的相同图像的链接

https://contact1881.000webhostapp.com/images/tom_cruise.jpg

我真的在这里做错了什么？请帮帮我

这是主页片段

public class HomeFragment extends Fragment implements Response.Listener , Response.ErrorListener {

    View view;
    RecyclerView mRecyclerView;
    private RecyclerView.LayoutManager mLayoutManager;
    private Context context;
    private List<Model> contactList  = new ArrayList<>();
    private String url ="https://api.androidhive.info/json/contacts.json";
    Button btn;
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.home_fragment,container,false);
        context = getContext();
        mLayoutManager = new GridLayoutManager(context,2);
        mRecyclerView = (RecyclerView)view.findViewById(R.id.my_recycler_view);
        mRecyclerView.setLayoutManager(mLayoutManager);
        mRecyclerView.setHasFixedSize(true);
        mRecyclerView.setLayoutManager(mLayoutManager);
        getContactList();
        return view;
    }

    private void getContactList(){
        Log.d("TEST","Getting Contact list");
        Controller.getInstance(context).makeNetworkCalls(Request.Method.GET,url,this,this);
    }

    @Override
    public void onErrorResponse(VolleyError error) {
        Log.e(TAG, "Error: " + error.getMessage());
        Toast.makeText(context, "Error: " + error.getMessage(), Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onResponse(Object response) {
        Log.d("TEST","Got The response" +response);
        if (response == null) {
            Toast.makeText(context, "Couldn't fetch the contacts! Pleas try again.", Toast.LENGTH_LONG).show();
            return;
        }

        List<Model> items = new Gson().fromJson(response.toString(), new TypeToken<List<Model>>(){}.getType());
        contactList.addAll(items);
        MyAdapter rcAdapter = new MyAdapter(contactList,context);
        mRecyclerView.setAdapter(rcAdapter);
    }
}

而图像加载器类是

public class MySingleton {
    private static MySingleton mInstance;
    private RequestQueue mRequestQueue;
    private ImageLoader mImageLoader;
    private static Context mCtx;

    private MySingleton(Context context) {
        mCtx = context;
        mRequestQueue = getRequestQueue();

        mImageLoader = new ImageLoader(mRequestQueue,
                new ImageLoader.ImageCache() {
                    private final LruCache<String, Bitmap>
                            cache = new LruCache<String, Bitmap>(20);

                    @Override
                    public Bitmap getBitmap(String url) {
                        return cache.get(url);
                    }

                    @Override
                    public void putBitmap(String url, Bitmap bitmap) {
                        cache.put(url, bitmap);
                    }
                });
    }

    public static synchronized MySingleton getInstance(Context context) {
        if (mInstance == null) {
            mInstance = new MySingleton(context);
        }
        return mInstance;
    }

    public RequestQueue getRequestQueue() {
        if (mRequestQueue == null) {
            // getApplicationContext() is key, it keeps you from leaking the
            // Activity or BroadcastReceiver if someone passes one in.
            mRequestQueue = Volley.newRequestQueue(mCtx.getApplicationContext());
        }
        return mRequestQueue;
    }

    public <T> void addToRequestQueue(Request<T> req) {
        getRequestQueue().add(req);
    }

    public ImageLoader getImageLoader() {
        return mImageLoader;
    }
}

适配器类是

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
    private List<Model> mDataset;
    private ImageLoader mImageLoader;
    // Provide a reference to the views for each data item
    // Complex data items may need more than one view per item, and
    // you provide access to all the views for a data item in a view holder
    public static class ViewHolder extends RecyclerView.ViewHolder {
        // each data item is just a string in this case
        public TextView nameText;
        public TextView phoneText;
        public NetworkImageView image;
        @SuppressLint("WrongViewCast")
        public ViewHolder(View v) {
            super(v);
            nameText = v.findViewById(R.id.name_text);
            phoneText = v.findViewById(R.id.phone_text);
            image = v.findViewById(R.id.imgAvatar);
            image.setDefaultImageResId(R.mipmap.ic_launcher);
            v.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(v.getContext(),"Position: "+getAdapterPosition(), Toast.LENGTH_SHORT).show();
                }
            });
        }
    }

    // Provide a suitable constructor (depends on the kind of dataset)
    public MyAdapter(List<Model> myDataset, Context mCOntext) {
        Log.d("TEST",myDataset.get(0).getName());
        mDataset = myDataset;
        mImageLoader = MySingleton.getInstance(mCOntext).getImageLoader();
    }

    // Create new views (invoked by the layout manager)
    @Override
    public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                                   int viewType) {
        // create a new view
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.card_view, parent, false);
        // set the view's size, margins, paddings and layout parameters

        ViewHolder vh = new ViewHolder(v);
        return vh;
    }

    // Replace the contents of a view (invoked by the layout manager)
    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        // - get element from your dataset at this position
        // - replace the contents of the view with that element
        //holder.mTextView.setText(mDataset.get(position).getName());
        Log.d("TEST","Printing Names onBindView Holder"+mDataset.get(position).getName());
        holder.nameText.setText(mDataset.get(position).getName());
        holder.phoneText.setText(mDataset.get(position).getPhone());
        holder.image.setImageUrl(mDataset.get(position).getImage(),mImageLoader);

    }

    // Return the size of your dataset (invoked by the layout manager)
    @Override
    public int getItemCount() {
        return mDataset.size();
    }
}

提前致谢。

Answer 1

我的建议：

如果您想参考 Volley Library 在 RecyclerView 中显示图像或任何其他数据，请按照以下教程进行操作：

Volley RecyclerView

或（更好的选择）

如果您想参考 Retrofit Library 来在 RecyclerView 中显示图像或任何其他数据，请按照以下教程进行操作：

Retrofit RecyclerView

IMO，去 Retrofit Library，它比 Volley 好而且更好。

快乐编码。