Question

我的代码有问题，这是错误的

java.lang.NullPointerException：尝试调用虚拟方法空对象上的'void android.widget.ImageView.setImageResource（int）' 参考

代码中没有错误，但是运行时会出现null异常错误，我不知道哪里是null，这是错误

在
com.mulazi.submission2.MovieListAdapter.onBindViewHolder（MovieListAdapter.java:57）在com.mulazi.submission2.MovieListAdapter.onBindViewHolder（MovieListAdapter.java:20）

这是我的代码

package com.mulazi.submission2;

import android.content.Intent;
import android.provider.ContactsContract;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.mulazi.submission2.R;
import com.mulazi.submission2.DetailActivity;
import com.mulazi.submission2.Movie;

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

public class MovieListAdapter extends RecyclerView.Adapter<MovieListAdapter.MovieViewHolder>  {
    private List<Movie> movieList;

    public MovieListAdapter() {
        movieList = new ArrayList<>();
    }

    private void add(Movie item) {
        movieList.add(item);
        notifyItemInserted(movieList.size() - 1);
    }

    public void addAll(List<Movie> movieList) {
        for (Movie movie : movieList) {
            add(movie);
        }
    }

    @NonNull
    @Override
    public MovieViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_movie, parent, false);
        return new MovieViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull final MovieViewHolder holder,final int position) {
        final Movie movie = movieList.get(position);
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(holder.itemView.getContext(), DetailActivity.class);
                intent.putExtra("key", movie);
                holder.itemView.getContext().startActivity(intent);
            }
        });

        holder.moviePhoto.setImageResource(movie.getPhoto());
        holder.movieName.setText(movie.getName());
        holder.movieDate.setText(movie.getDate());
        holder.movieDesc.setText(movie.getDescription());
        holder.movieDuration.setText(movie.getDuration());
        holder.movieDirector.setText(movie.getDirector());
        holder.movieGenre.setText(movie.getGenre());
    }

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

    static class MovieViewHolder extends RecyclerView.ViewHolder {
        ImageView moviePhoto;
        TextView movieName;
        TextView movieDesc;
        TextView movieDate;
        TextView movieDuration;
        TextView movieDirector;
        TextView movieGenre;

        MovieViewHolder(@NonNull View itemView) {
            super(itemView);

            moviePhoto = itemView.findViewById(R.id.img_photo);
            movieName = itemView.findViewById(R.id.txt_name);
            movieDesc = itemView.findViewById(R.id.txt_description);
            movieDate = itemView.findViewById(R.id.txt_date);
            movieDirector = itemView.findViewById(R.id.txt_director);
            movieDuration = itemView.findViewById(R.id.txt_duration);
            movieGenre = itemView.findViewById(R.id.txt_genre);
        }
    }
}

我希望有人能帮助我解决此错误，

Answer 1

检查布局文件。您很可能忘记将img_photo放入布局中：

moviePhoto = itemView.findViewById(R.id.img_photo);

我运行项目时出现NullPointerException

1 个答案: