Question

我想在我的适配器中使用片段共享元素事务。按下时显示细节阅读更多按钮，但我不能这样做。我不知道我的错在哪里。任何的想法？

import android.app.Activity;
import android.content.Context;
import android.os.Build;
import android.support.design.widget.Snackbar;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.widget.RecyclerView;
import android.transition.Transition;
import android.transition.TransitionInflater;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.TextView;

import java.util.List;

/**
 * Created by r00t on 16.12.2015.
 */
public class NewsListAdapter extends     RecyclerView.Adapter<NewsListAdapter.ViewHolder>{
private List<NewsModel> newsModels;
private Context context;
private int lastPosition = -1;

public NewsListAdapter(Context context, List<NewsModel> feedItemList) {
    this.newsModels = feedItemList;
    this.context = context;
}
public class ViewHolder extends RecyclerView.ViewHolder {
    protected TextView title;
    protected TextView desc;
    protected TextView readmore;
    public ViewHolder(View view) {
        super(view);
        this.title = (TextView) view.findViewById(R.id.asd);
        this.desc = (TextView) view.findViewById(R.id.desc);
        this.readmore = (TextView) view.findViewById(R.id.readmore);
    }
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.news_recyclerlist_item, parent, false);
    ViewHolder view_holder = new ViewHolder(v);
    return view_holder;
}

@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
    setAnimation(holder.itemView, position);
    holder.title.setText(newsModels.get(position).getTitle());
    holder.desc.setText(newsModels.get(position).getDesc());
    holder.readmore.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            NewsFragment newsFragment = new NewsFragment();
            NewsDetailFragment newsDetailFragment = new NewsDetailFragment();
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                Transition changeTransform = TransitionInflater.from(v.getContext()).
                        inflateTransition(R.transition.change_image_transform);
                Transition explodeTransform = TransitionInflater.from(v.getContext()).
                        inflateTransition(android.R.transition.explode);

                newsFragment.setSharedElementReturnTransition(changeTransform);
                newsFragment.setExitTransition(explodeTransform);

                newsDetailFragment.setSharedElementEnterTransition(changeTransform);
                newsDetailFragment.setEnterTransition(explodeTransform);

                TextView title = (TextView) v.findViewById(R.id.asd);

                FragmentTransaction fragmentTransaction = ((Activity)context).getFragmentManager()
                        .beginTransaction()
                        .replace(R.id.flContent, newsDetailFragment)
                        .addToBackStack("s")
                        .addSharedElement(title, "dsa");
                fragmentTransaction.commit();
            }            }
    });
}

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

@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
    super.onAttachedToRecyclerView(recyclerView);
}

private void setAnimation(View viewToAnimate, int position)
{
    if (position > lastPosition)
    {
        Animation animation = AnimationUtils.loadAnimation(context, android.R.anim.slide_in_left);
        viewToAnimate.startAnimation(animation);
        lastPosition = position;
    }
}

}

我得到了这个错误。我不知道我要做什么。

02-08 16:30:59.565 2755-2755/? E/AndroidRuntime: FATAL EXCEPTION: main
                                             Process: com.lux.lux, PID: 2755
                                             java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.view.View.getTransitionName()' on a null object reference
                                                 at android.app.BackStackRecord.addSharedElement(BackStackRecord.java:565)
                                                 at com.lux.lux.adapters.NewsListAdapter$1.onClick(NewsListAdapter.java:79)
                                                 at android.view.View.performClick(View.java:5198)
                                                 at android.view.View$PerformClick.run(View.java:21147)
                                                 at android.os.Handler.handleCallback(Handler.java:739)
                                                 at android.os.Handler.dispatchMessage(Handler.java:95)
                                                 at android.os.Looper.loop(Looper.java:148)
                                                 at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                 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)

Android-Fragment共享元素事务ERROR

0 个答案: