我想从内部 class (ViewHolder) 调用 Toast 消息

Question

主要是出于测试目的，我希望能够通过单击我在 ViewHolder 中为 RecyclerView 引用的 imageView 来创建 Toast 消息，但我不知道如何向它传递上下文。任何帮助，将不胜感激。

package com.checkinsystems.ez_score.utils;

import android.app.Activity;
import android.content.Context;
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 android.widget.Toast;

import com.checkinsystems.ez_score.R;
import com.checkinsystems.ez_score.Sample.TestActivity;
import com.checkinsystems.ez_score.model.Match;

import java.util.List;


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

    private List<Match> mMatches;
    private Context mContext;

    public MatchItemAdapter(Context context, List<Match> items){
        this.mContext = context;
        this.mMatches = items;
    }

    @Override
    public MatchItemAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        LayoutInflater inflater = LayoutInflater.from(mContext);
        View itemView = inflater.inflate(R.layout.list_item_match, parent, false);
        ViewHolder viewHolder = new ViewHolder(itemView);

        return viewHolder;
    }

    @Override
    public void onBindViewHolder(MatchItemAdapter.ViewHolder holder, int position) {
        Match match = mMatches.get(position);

        try {
            holder.tvName.setText(match.getMatchName());
            holder.tvDate.setText(match.getMatchDate());
            holder.imageView.findViewById(R.id.imageView);
        } catch (Exception e) {
            e.printStackTrace();
        }


    }

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


    public static class ViewHolder extends RecyclerView.ViewHolder{

        public TextView tvName;
        public TextView tvDate;
        public ImageView imageView;

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

            tvName = (TextView)itemView.findViewById(R.id.match_name);
            tvDate = (TextView)itemView.findViewById(R.id.match_date);
            imageView = (ImageView)itemView.findViewById(R.id.imageView);

            imageView.setOnClickListener(new View.OnClickListener(){

                @Override
                public void onClick(View view) {
                    Toast.makeText(, "onClick working", Toast.LENGTH_LONG).show();
                }
            });
        }
    }
}

据我所知，您不能从未扩展 Activity class 的内容中调用 Toast 消息，但必须有某种类型的变通方法。

Answer 1

使用view.getContext()

public void onClick(View view) {
    Toast.makeText(view.getContext(), "onClick working", Toast.LENGTH_LONG).show();
}

我想从内部 class (ViewHolder) 调用 Toast 消息

I want to call a Toast message from an inner class (ViewHolder)

android

android-toast

android-recyclerview