使用Butterknife

Question

我知道这个问题已被多次询问，但这些问题都没有解决我的问题。堆栈跟踪看起来像这样。

    02-09 19:39:20.364 18846-18846/com.michael1011.tweetcomposer E/AndroidRuntime: FATAL EXCEPTION: main
   Process: com.michael1011.tweetcomposer, PID: 18846
   java.lang.RuntimeException: Unable to start activity ComponentInfo{com.michael1011.tweetcomposer/com.michael1011.tweetcomposer.login}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2450)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2520)
       at android.app.ActivityThread.-wrap11(ActivityThread.java)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1363)
       at android.os.Handler.dispatchMessage(Handler.java:102)
       at android.os.Looper.loop(Looper.java:148)
       at android.app.ActivityThread.main(ActivityThread.java:5466)
       at java.lang.reflect.Method.invoke(Native Method)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
    Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
       at android.support.design.widget.Snackbar.setText(Snackbar.java:334)
       at android.support.design.widget.Snackbar.make(Snackbar.java:210)
       at com.michael1011.tweetcomposer.login.onCreate(login.java:43)
       at android.app.Activity.performCreate(Activity.java:6251)
       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108)
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2403)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2520) 
       at android.app.ActivityThread.-wrap11(ActivityThread.java) 
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1363) 
       at android.os.Handler.dispatchMessage(Handler.java:102) 
       at android.os.Looper.loop(Looper.java:148) 
       at android.app.ActivityThread.main(ActivityThread.java:5466) 
       at java.lang.reflect.Method.invoke(Native Method) 
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

适配器类看起来与此类似

package com.example.babu.moviemanager;

import android.content.Context;
import android.support.v7.widget.CardView;
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.squareup.picasso.Picasso;

import java.util.List;

import butterknife.BindView;
import butterknife.ButterKnife;


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


    Context context;
    List<Movie> movieList;

    public CustomAdapter(Context context, List<Movie> movieList) {
        this.context = context;
        this.movieList = movieList;
    }

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

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {

        Movie movie=movieList.get(position);
        holder.title.setText(movie.getTitle());
        holder.overview.setText(movie.getOverview());
        Picasso.with(getcontext()).load(movie.getPosterPath()).into(holder.poster);

    }

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

    public Context getcontext() {
        return context;
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        @BindView(R.id.imageContainer)
        ImageView poster;
        @BindView(R.id.titleContainer)
        TextView title;
        @BindView(R.id.overviewContainer)
        TextView overview;
        @BindView(R.id.card)
        CardView cardView;

        public ViewHolder(View itemView) {
            super(itemView);
            ButterKnife.bind(itemView);
        }
    }
}

我尝试了堆叠溢出的所有解决方案，但这些似乎都不适用，我会感激任何帮助的人。如果你打算投票，请告诉我为什么？

Answer 1

根据butterknife文档，您在视图持有者中使用的绑定方法必须接受视图目标bind(this)或查看目标并查看源bind(this,view)。在您的情况下，将绑定方法更改为bind(this,itemView)，它应该可以工作。

Answer 2

将ButterKnife依赖项更改为最新版本可以为我解决。

    dependencies {
      ...
      implementation 'com.jakewharton:butterknife:10.2.0'
      annotationProcessor 'com.jakewharton:butterknife-compiler:10.2.0'
  }