Question

我的适配器：

public class Adaptor extends RecyclerView.Adapter<Adaptor.Holder>{

private ArrayList<Winkel> winkels;
private LayoutInflater inflater;
private ImageView icon;
private ItemCLickCallback itemCLickCallback;

public interface ItemCLickCallback {
    void onItemClick(int p);
    void onSecItemClick(int p);

}

public void setItemCLickCallback(final ItemCLickCallback itemCLickCallback1){
    this.itemCLickCallback = itemCLickCallback;
}

public Adaptor (ArrayList<Winkel> winkels,Context c){
    this.inflater = LayoutInflater.from(c);
    this.winkels = winkels;
}


@Override
public Holder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = inflater.inflate(R.layout.card_item, parent, false);
    return new Holder(view);
}

@Override
public void onBindViewHolder(Holder holder, int position) {
    Winkel winkel = winkels.get(position);
    holder.title.setText(winkel.getNaam());
    if (winkel.isFavourtite()){
        holder.icon.setImageResource(R.drawable.ic_star_black_18dp);
    }
    else{
        holder.icon.setImageResource(R.drawable.ic_star_border_black_18dp);
    }

}

@Override
public int getItemCount() {

    return winkels.size();
}

class Holder extends RecyclerView.ViewHolder implements View.OnClickListener{

    private TextView title;
    private View container;
    private ImageView icon;

    public Holder(View itemView) {
        super(itemView);

        title = (TextView)itemView.findViewById(R.id.lbl_item_text);
        container = itemView.findViewById(R.id.cont_item_root);
        icon = (ImageView) itemView.findViewById(R.id.im_item_icon_secondary);
        icon.setOnClickListener(this);
        container.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        if(v.getId()==R.id.cont_item_root){
            Log.d("lol",Integer.toString(getAdapterPosition()));
            itemCLickCallback.onItemClick(getAdapterPosition());

        }
        else{
            itemCLickCallback.onSecItemClick(getAdapterPosition());
        }
    }
}
}

我的概述片段：

@Override
public void onItemClick(int p) {
    Log.d("lol",(Integer.toString(p)));
    Winkel winkel = (Winkel) mijnwinkels.get(p);

    Bundle detailsBundle = new Bundle();
    detailsBundle.putString(DETAILS_NAAM,winkel.getNaam());
    detailsBundle.putString(DETAILS_ADRES,winkel.getAdres());
    detailsBundle.putString(DETAILS_DEELGEMEENTE,winkel.getDeelGemeente());
    detailsBundle.putString(DETAILS_GEMEENTE,winkel.getGemeente());
    detailsBundle.putString(DETAILS_POSTCODE,winkel.getPostcode());

    Details detail= new Details();
    detail.setArguments(detailsBundle);
    this.getFragmentManager().beginTransaction()
            .replace(R.id.details,detail,null)
            .addToBackStack(null)
            .commit();
}

错误讯息：

java.lang.NullPointerException: Attempt to invoke interface method 'void com.example.hoofdgebruiker.winkelskortrijk.Utill.Adaptor$ItemCLickCallback.onItemClick(int)' on a null object reference.

我的代码正在努力，我得到了recyclerview，项目在其中，但我不能点击其中任何一个而不会出现此错误，我不明白为什么。我做错了它是一个空对象引用？我的日志都没有显示出来。

编辑：我的方法onItemCLickCallback在这里使用：

@Override
public void onSuccess(ArrayList<Winkel> winkels) {
    mijnwinkels = winkels;
    Adaptor adaptor = new Adaptor(mijnwinkels, this.getActivity());
    mRecyclerView.setLayoutManager(new LinearLayoutManager(this.getActivity()));
    mRecyclerView.addItemDecoration(new VerticalSpace(30));
    mRecyclerView.setAdapter(adaptor);
    adaptor.setItemCLickCallback(this);
}

Answer 1

您的方法参数中存在拼写错误

public void setItemCLickCallback(final ItemCLickCallback itemCLickCallback1){
    this.itemCLickCallback = itemCLickCallback;
}

您期待itemCLickCallback1并指定itemCLickCallback（注意额外＆＃39; 1＆＃39;作为后缀的区别）。

Recyclerview on click null对象引用

1 个答案: