Question

我有这个愚蠢的问题。我搜索了它，但无法得到任何回复，因此我在这里发布了它。

在下面的片段中，我有一个recyclerview，它在 Gson 的帮助下用 Post POJO 填充来自服务器的数据。

我在我的另一个项目中多次使用类似的代码，但今天我收到一个错误，因为我的recyclerview没有显示值。所以我调试代码并得到以下输出，显示＆＃39; this＆＃39;我的回收视图在Volley的 onResponse 中无法使用。

My Fragment类如下：

public class Seller_Corner_Tab2 extends Fragment implements PostAdapter.OnItemClickListener {

public static final String TAG = Seller_Corner_Tab2.class.getSimpleName();

RecyclerView recyclerView;
ProgressDialog progressDialog;
AppPreferences preferences;

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

    View view = inflater.inflate(R.layout.seller_corner_tab2,container,false);

    preferences = new AppPreferences(getActivity());

    recyclerView = (RecyclerView)view.findViewById(R.id.seller_corner_2_rv);
    LinearLayoutManager mLinearLayoutManagerVertical = new LinearLayoutManager(getContext()); // (Context context)
    mLinearLayoutManagerVertical.setOrientation(LinearLayoutManager.VERTICAL);
    recyclerView.setLayoutManager(mLinearLayoutManagerVertical);
    progressDialog = new ProgressDialog(getContext());

    /*progressDialog.setMessage("Loading your Posts");
    progressDialog.setCancelable(false);
    progressDialog.show();*/
    fetchSellerPosts();

    return view;
}

public void fetchSellerPosts() {

    final Seller seller = EKrushiKattaApplication.getInstance().getPrefManager().getSeller();

    StringRequest strReq = new StringRequest(Request.Method.POST,
            EndPoints.GETPOSTBYID, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            ArrayList<Post>templist = new ArrayList<>();
            /*progressDialog.hide();*/
            try {
                GsonBuilder gsonbuilder= new GsonBuilder();
                Gson gson=gsonbuilder.create();
                Log.e("Response",response);
                templist =gson.fromJson(response, new TypeToken<List<Post>>(){}.getType());

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

            recyclerView.setAdapter( new PostAdapter(templist,getContext(),Seller_Corner_Tab2.this));

        }
    }, new Response.ErrorListener() {

        @Override
        public void onErrorResponse(VolleyError error) {
            progressDialog.hide();
            NetworkResponse networkResponse = error.networkResponse;
            Log.e(TAG, "Connection error: " + error.getMessage() + ", code: " + networkResponse);
            Toast.makeText(getActivity(), "Volley error: " + error.getMessage(), Toast.LENGTH_SHORT).show();
        }
    }) {

        @Override
        protected Map<String, String> getParams() {
            Map<String, String> params = new HashMap<>();

            params.put(CommonLib.SELLER_ID,String.valueOf(seller.getSellerId()));

            Log.e(TAG, "params: " + params.toString());
            return params;
        }
    };

    //Adding request to request queue
    EKrushiKattaApplication.getInstance().addToRequestQueue(strReq);

}

@Override
public void onItemClick(Post post) {

}}

我的调试器显示了此输出

我的PostAdapter类如下：

public class PostAdapter extends RecyclerView.Adapter<PostAdapter.ViewHolder>{

private ArrayList<Post> posts;
private Context context;
private OnItemClickListener listener;

public PostAdapter(ArrayList<Post> posts, Context context, OnItemClickListener listener) {
    this.posts = posts;
    this.context = context;
    this.listener = listener;
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

    View view = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.item_post, parent, false);

    return new ViewHolder(view);
}

@Override
public void onBindViewHolder(final ViewHolder holder, int position) {

    if(posts!=null){

        final Post post = posts.get(position);

            holder.title.setText(post.getPostTitle());
            holder.desc.setText(post.getPostDescription());
            holder.cost.setText(post.getPostCost());

            RequestOptions options = new RequestOptions()
                    .centerCrop()
                   // .placeholder(R.drawable.placeholder)
                  //  .error(R.drawable.ic_pic_error)
                    .priority(Priority.HIGH);

            new GlideImageLoader(holder.image,
                    holder.progressBar).load(EndPoints.BASE_URL+post.getPostImage(),options);

            holder.itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    listener.onItemClick(post);
                }
            });
    }
}

@Override
public int getItemCount() {
    int size=0;
    try {
        size = posts.size();
    } catch (Exception e) {
        e.printStackTrace();
    }
    return size;
}

@Override
public long getItemId(int position) {
    return super.getItemId(position);
}

class ViewHolder extends RecyclerView.ViewHolder{

    ImageView image;
    TextView title,desc,cost;
    ProgressBar progressBar;

    public ViewHolder(View itemView) {
        super(itemView);

        image=(ImageView)itemView.findViewById(R.id.post_item_image);
        title=(TextView)itemView.findViewById(R.id.post_item_title);
        desc=(TextView)itemView.findViewById(R.id.post_item_desc);
        cost=(TextView)itemView.findViewById(R.id.post_item_cost);
        progressBar=(ProgressBar)itemView.findViewById(R.id.post_item_progressbar);
    }
}

public interface OnItemClickListener {
    void onItemClick(Post post);
}}

Answer 1

试试这个：

1）从onResponse()

中提取数据源

2）在回收者查看充气后立即创建适配器。

3）在onResponse()填充新数据的数据源中。

4）在适配器中调用notifyDatasetChanged()。

public class Seller_Corner_Tab2 extends Fragment implements PostAdapter.OnItemClickListener {

public static final String TAG = Seller_Corner_Tab2.class.getSimpleName();

RecyclerView recyclerView;
ProgressDialog progressDialog;
AppPreferences preferences;
ArrayList<Post>templist = new ArrayList<>();
PostAdapter adapter;

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

    View view = inflater.inflate(R.layout.seller_corner_tab2,container,false);

    preferences = new AppPreferences(getActivity());

    recyclerView = (RecyclerView)view.findViewById(R.id.seller_corner_2_rv);
    LinearLayoutManager mLinearLayoutManagerVertical = new LinearLayoutManager(getContext()); // (Context context)
    mLinearLayoutManagerVertical.setOrientation(LinearLayoutManager.VERTICAL);
    recyclerView.setLayoutManager(mLinearLayoutManagerVertical);
    progressDialog = new ProgressDialog(getContext());
    adapter =  new PostAdapter(templist,getContext(),this);
    recyclerView.setAdapter(adapter);
    /*progressDialog.setMessage("Loading your Posts");
    progressDialog.setCancelable(false);
    progressDialog.show();*/
    fetchSellerPosts();

    return view;
}

public void fetchSellerPosts() {

    final Seller seller = EKrushiKattaApplication.getInstance().getPrefManager().getSeller();

    StringRequest strReq = new StringRequest(Request.Method.POST,
            EndPoints.GETPOSTBYID, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            ArrayList<Post> newList = new ArrayList();
            /*progressDialog.hide();*/
            try {
                GsonBuilder gsonbuilder= new GsonBuilder();
                Gson gson=gsonbuilder.create();
                Log.e("Response",response);
                templist =gson.fromJson(response, new TypeToken<List<Post>>(){}.getType());

            }catch (Exception e)
            {
                e.printStackTrace();
            }
            templist.addAll(newList);
            adapter.notifyDatasetChanged();




        }
    }, new Response.ErrorListener() {

        @Override
        public void onErrorResponse(VolleyError error) {
            progressDialog.hide();
            NetworkResponse networkResponse = error.networkResponse;
            Log.e(TAG, "Connection error: " + error.getMessage() + ", code: " + networkResponse);
            Toast.makeText(getActivity(), "Volley error: " + error.getMessage(), Toast.LENGTH_SHORT).show();
        }
    }) {

        @Override
        protected Map<String, String> getParams() {
            Map<String, String> params = new HashMap<>();

            params.put(CommonLib.SELLER_ID,String.valueOf(seller.getSellerId()));

            Log.e(TAG, "params: " + params.toString());
            return params;
        }
    };

    //Adding request to request queue
    EKrushiKattaApplication.getInstance().addToRequestQueue(strReq);

}

@Override
public void onItemClick(Post post) {

}}

调试器显示 - ＆gt; ＆＃39;这＆＃39;在Recyclerview的onResponse排球方法中不可用

1 个答案: