我的CustomAdapter
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.CustomViewHolder> {
private List<RetroProduct> dataList;
private Context context;
CustomAdapter(Context context, List< RetroProduct > dataList){
this.context = context;
this.dataList = dataList;
}
class CustomViewHolder extends RecyclerView.ViewHolder {
final View mView;
TextView goodsId,categoryTitle,number,title1,title2;
CustomViewHolder(View itemView) {
super(itemView);
mView = itemView;
goodsId = mView.findViewById(R.id.tv_goodsId);
categoryTitle = mView.findViewById(R.id.tv_categoryTitle);
number = mView.findViewById(R.id.tv_number);
title1 = mView.findViewById(R.id.tv_title1);
title2 = mView.findViewById(R.id.tv_title2);
}
}
@NonNull
@Override
public CustomViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
View view = layoutInflater.inflate(R.layout.item_row, parent, false);
return new CustomViewHolder(view);
}
@Override
public void onBindViewHolder(CustomViewHolder holder, int position) {
holder.goodsId.setText(dataList.get(position).getGoodsId());
holder.categoryTitle.setText(dataList.get(position).getCategoryTitle());
holder.title1.setText(dataList.get(position).getTitle1());
holder.title2.setText(dataList.get(position).getTitle2());
holder.number.setText(dataList.get(position).getNumber());
}
@Override
public int getItemCount() {
return dataList.size();
}
}
并且我在]上获得NullPointerException
return dataList.size();
我现在应该做什么?给它值,或者我不知道。MainActivity
public class MainActivity extends AppCompatActivity { private CustomAdapter adapter; private RecyclerView recyclerView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); GetDataService service = RetrofitClientInstance.getRetrofitInstance() .create(GetDataService.class); Call< List<RetroProduct> > call = service.getAllProducts(); call.enqueue(new Callback<List<RetroProduct>>() { @Override public void onResponse(Call<List<RetroProduct>> call, Response<List<RetroProduct>> response) { generateDataList(response.body()); LinearLayoutManager manager = new LinearLayoutManager(MainActivity.this); recyclerView.setLayoutManager(manager); recyclerView.setHasFixedSize(true); recyclerView.setAdapter(adapter); adapter.notifyDataSetChanged(); } @Override public void onFailure(Call<List<RetroProduct>> call, Throwable t) { Toast.makeText(MainActivity.this, "null", Toast.LENGTH_SHORT).show(); } }); } private void generateDataList(List<RetroProduct> productList) { recyclerView = findViewById(R.id.recycler_view); adapter = new CustomAdapter(this,productList); } }
im是android编程中的新增功能,我想将JSON添加到我的recyclerview中,我没有使适配器没有跳过跳过布局,但我的CustomAdapter也给了我NullPointerException。我的...
@Override
public int getItemCount() {
if(dataList!=null)
return dataList.size();
else
return 0;
}