Question

日志和编码部分未显示任何错误。运行时，它仅显示带有虚拟设备的灰色屏幕。因此，我不知道该片段部分发生了什么。基本上，我的活动和Java片段是分开的，因此以下部分是片段编码部分。希望大家能帮助我解决这个问题。谢谢。

    public class ProductListFragment extends Fragment {
    private RecyclerView mProductRecyclerView;
    private ProductAdapter mAdapter;


    private class ProductHolder extends RecyclerView.ViewHolder {
        private Product mProduct;
        private TextView mTitleTextView;
        private TextView mPrice;

        public ProductHolder(LayoutInflater inflater, ViewGroup parent){
            super(inflater.inflate(R.layout.list_item_product,parent, false));
            // itemView.setOnClickListener(this);
            mTitleTextView = (TextView) itemView.findViewById(R.id.product_title);
            mPrice = (TextView) itemView.findViewById(R.id.price);
        }
        public void bind(Product product){
            mProduct = product;
            mTitleTextView.setText(mProduct.getProductName());
            mPrice.setText(mProduct.getPrice());
        }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
        View view = inflater.inflate(R.layout.fragment_product_list,container,false);

        mProductRecyclerView = (RecyclerView) view.findViewById(R.id.product_recycler_view);
        mProductRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
        updateUI();
        return view;
    }
    private void updateUI(){
        ProductLab productLab = ProductLab.get(getActivity());
        List<Product> products = productLab.getProducts();
        if (mAdapter ==null){
            mAdapter = new ProductAdapter(products);
            mProductRecyclerView.setAdapter(mAdapter);
        }else{
            mAdapter.setProducts(products);
            mAdapter.notifyDataSetChanged();
        }

    }
    //Adapter
    private class ProductAdapter extends RecyclerView.Adapter<ProductHolder>{
        private List<Product> mProducts;

        public ProductAdapter(List<Product> products){
            mProducts= products;
        }
        @Override
        public ProductHolder onCreateViewHolder(ViewGroup parent,int viewType){
            LayoutInflater layoutInflater = LayoutInflater.from(getActivity());
            return new ProductHolder(layoutInflater, parent);
        }
        @Override
        public void onBindViewHolder(ProductHolder holder, int position){
            Product product = mProducts.get(position);
            holder.bind(product);
        }
        @Override
        public int getItemCount(){

            return mProducts.size();
        }
        public void setProducts(List<Product> products){
            mProducts= products;
    }
    }
}

Answer 1

一个问题是调用updateUI()函数。您在错误的地方叫它

读取片段的生命周期，因为这不是从onCreateView访问视图元素的好习惯
在onViewCreated内调用UI更新功能
getActivity()无处不在，我建议声明一个父活动的类成员，然后在onAttach(context: Context)函数中对其进行初始化，然后在需要时传递变量

运行显示灰屏的Android Studio应用程序

1 个答案: