svgLoader没有当前类的reffernce就无法工作

Question

这是我通过这个类的主要类我从api通过url获取数据并使One Adapter类维护它但发生意外错误。

这是MainActivity.java：

 public class MainActivity extends AppCompatActivity {
   RecyclerView recyclerView;
   RecyclerView.Adapter adapter;
   public static SvgLoader svgLoader;
   private  final String Url="https://restcountries.eu/rest/v2/all";
   List<ListItem> listItems;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    recyclerView=(RecyclerView)findViewById(R.id.recycleview);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));

    listItems = new ArrayList<>();

loadRecyclerViewData();



}

private void loadRecyclerViewData() {
    final ProgressDialog progressDialog = new ProgressDialog(this);
    progressDialog.setMessage("Loading Data.....");
    progressDialog.show();

    StringRequest stringRequest= new StringRequest(Request.Method.GET,
            Url, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {

                progressDialog.dismiss();
            try {
                JSONArray json = new JSONArray(response);

                for (int i=0; i<json.length();i++)
                {
                    JSONObject o = json.getJSONObject(i);
                //   String  NewString = o.getString("callingCode").toString();
               //    System.out.println("hjashsdgx = "+NewString);
                 //   String  NewString2 = NewString.replaceAll("[\"/[ /]]", "");
                  //  JSONArray jsoncallingCode = new JSONArray("callingCodes");
                 //   JSONObject callingcode =jsoncallingCode.getJSONObject(1);
                    ListItem item = new ListItem(o.getString("name")
                            ,"+"+o.getString(
                                    "callingCodes").replace("]","")
                            .replace("[","").replace("\"","")
                            ,o.getString("flag"));


                    listItems.add(item);
                }

            adapter = new MyAdapter(listItems,getApplicationContext());
                recyclerView.setAdapter(adapter);


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

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            progressDialog.dismiss();
            Toast.makeText(MainActivity.this, error.getMessage(), Toast.LENGTH_SHORT).show();
        }
    });


    RequestQueue requestQueue = Volley.newRequestQueue(this);
    requestQueue.add(stringRequest);
}

@Override
protected void onDestroy() {
    super.onDestroy();
    SvgLoader.pluck().close();
}
}

这是我的MyAdapter.java。此活动在第29行的SvgLoader点发生错误。

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

  private List<ListItem> listItems;
  private Context context;
  public MyAdapter()
   {}
   public MyAdapter(List<ListItem> listItems, Context context) {
    this.listItems = listItems;
    this.context = context;
}

  @Override
  public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View v = 
   LayoutInflater.from(parent.getContext()).inflate(R.layout.cartview,null);
    return new ViewHolder(v);
  }

   @Override
   public void onBindViewHolder(ViewHolder holder, int position) {
    ListItem listItem = listItems.get(position);
    holder.heading.setText(listItem.getHead());
    holder.desc.setText(listItem.getDesc());
    SvgLoader.pluck()

  .with(new MainActivity())  // error occur here...


            .setPlaceHolder(R.mipmap.ic_launcher, R.mipmap.ic_launcher)
          .load(listItem.getImageurl().toString(), holder.imageView);


}

@Override
public int getItemCount() {
    return listItems.size();
}

public class ViewHolder extends RecyclerView.ViewHolder{
      public   TextView heading ;
      public TextView desc;
      public ImageView imageView;


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

        heading=(TextView) itemView.findViewById(R.id.heading);
        desc =(TextView) itemView.findViewById(R.id.desc);
        imageView=(ImageView)itemView.findViewById(R.id.imageload);
    }
}


 }

我不知道为什么会这样，有什么想法？

Answer 1

替换以下代码

<强> MainActivity.java

   adapter = new CountryAdapter(listItems, MainActivity.this); //Replace getApplicationContext() to MainActivity.this

<强> MyAdapter.java

  public MyAdapter(List<CountryListItem> listItems, Activity activity) {
    this.listItems = listItems;
    this.activity = activity;
}// pass activity replace of context


    SvgLoader.pluck()
    .with(activity)//Replace new MainActivity with activity
   .setPlaceHolder(R.mipmap.ic_launcher, R.mipmap.ic_launcher)
    .load(listItem.getImageUrl().toString(), holder.imageView);

Answer 2

试试这段代码：

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

  private List<ListItem> listItems;
  private Context context;
  public MyAdapter()
   {}
   public MyAdapter(List<ListItem> listItems, Context context) {
    this.listItems = listItems;
    this.context = context;
}

  @Override
  public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View v = 
   LayoutInflater.from(parent.getContext()).inflate(R.layout.cartview,null);
    return new ViewHolder(v);
  }

   @Override
   public void onBindViewHolder(ViewHolder holder, int position) {
    ListItem listItem = listItems.get(position);
    holder.heading.setText(listItem.getHead());
    holder.desc.setText(listItem.getDesc());
    SvgLoader.pluck()
    .with(context)
    .setPlaceHolder(R.mipmap.ic_launcher, R.mipmap.ic_launcher)
    .load(listItem.getImageurl().toString(), holder.imageView);


}

@Override
public int getItemCount() {
    return listItems.size();
}

public class ViewHolder extends RecyclerView.ViewHolder{
      public   TextView heading ;
      public TextView desc;
      public ImageView imageView;


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

        heading=(TextView) itemView.findViewById(R.id.heading);
        desc =(TextView) itemView.findViewById(R.id.desc);
        imageView=(ImageView)itemView.findViewById(R.id.imageload);
    }
}


 }