Question

我是Android开发的新手，但我正在尝试使用RecyclerView构建一个简单的应用程序。我已经按照几个不同教程的说明进行操作，但每当我启动应用程序时，我得到的只是一个空白屏幕。关于我可能出错的任何想法？我错过了一些代码吗？提前谢谢。

这是我的RecyclerViewAdapter：

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import java.util.Collections;
import java.util.List;


public class Recycler_View_Adapter extends RecyclerView.Adapter<View_Holder> {
    List<Data> list = Collections.emptyList();
    Context context;
    @Override
    public View_Holder onCreateViewHolder(ViewGroup parent, int viewType) {
        //Inflate the layout, initialize the View Holder
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_layout, parent, false);
        View_Holder holder = new View_Holder(v);
        return holder;
    }
    @Override
    public void onBindViewHolder(View_Holder holder, int position) {

        //Use the provided View Holder on the onCreateViewHolder method to populate the current row on the RecyclerView
        holder.title.setText(list.get(position).title);
        holder.description.setText(list.get(position).description);
        holder.imageView.setImageResource(list.get(position).imageId);

        //animate(holder);
    }
    @Override
    public int getItemCount() {
        //returns the number of elements the RecyclerView will display
        return list.size();
    }
    @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
    }
    // Insert a new item to the RecyclerView on a predefined position
    public void insert(int position, Data data) {
        list.add(position, data);
        notifyItemInserted(position);
    }
    // Remove a RecyclerView item containing a specified Data object
    public void remove(Data data) {
        int position = list.indexOf(data);
        list.remove(position);
        notifyItemRemoved(position);
    }

}

以下是我的MainActivity的代码

import android.app.Activity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

import java.util.ArrayList;
import java.util.List;


    public class MainActivity extends Activity {
        private RecyclerView mRecyclerView;
        private List<Data> data;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);


            List<Data> data = fill_with_data();

            Recycler_View_Adapter adapter = new Recycler_View_Adapter();
            mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
            mRecyclerView.setAdapter(adapter);
            mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

        }
        public List<Data> fill_with_data() {

            List<Data> data = new ArrayList<>();

            data.add(new Data("FTWT item", "ftwt item description ", R.drawable.ftwt1));
            data.add(new Data("Ftwt item 2", "ftwt item2 description ", R.drawable.ftwt2));
            data.add(new Data("ftwt merch", "ftwt merch description", R.drawable.ftwt_merch1));
            data.add(new Data("luca item 1", "luca item1 description", R.drawable.luca1));
            data.add(new Data("luca merch1", "luca merch1 description", R.drawable.luca_shirt1));
            data.add(new Data("luca merch2", "luca merch2 item description ", R.drawable.luca_shirt2));

            return data;
        }
    }

Answer 1

您似乎没有将data传递给您的适配器。

更改此

Recycler_View_Adapter adapter = new Recycler_View_Adapter();

到

Recycler_View_Adapter adapter = new Recycler_View_Adapter(data);

您的Recycler_View_Adapter list现在总是空着。添加构造函数以接受数据：

public Recycler_View_Adapter(List<Data> data){
    list = data;
}

显示RecyclerView内容时出错（加载空白屏幕）

1 个答案: