Question

我想实现RecyclerView的{{1}}版本，其中下面的给定代码从SQLite数据库中检索图像以在列表中显示它们。请帮助我了解如何实现这一目标。

ListView

Answer 1

这是我在项目中使用过的非常简单的适配器。希望您能从中学到东西，并且不希望我们为您编写代码。

    package com.example.contactexchange.Adapter;

import android.content.Context;
import android.database.Cursor;
import android.support.v7.widget.RecyclerView;
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.Button;
import android.widget.TextView;

import com.example.contactexchange.R;

import java.util.List;


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

    private List<String> mData;
    private LayoutInflater mInflater;
    private ItemClickListener mClickListener;
    private Context context;
    private int lastPosition = -1;

    public ChildrenRvAdapter(Context context, List<String> data) {
        this.mInflater = LayoutInflater.from(context);
        this.mData = data;
        this.context = context;
    }

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

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        String name = mData.get(position);
        holder.tv_name.setText(name);
        setAnimation(holder.itemView, position);
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        TextView tv_name;
        Button btn_remove;

        ViewHolder(View itemView) {
            super(itemView);
            tv_name = itemView.findViewById(R.id.tv_name);
            btn_remove = itemView.findViewById(R.id.btn_remove);
            btn_remove.setOnClickListener(this);
        }

        @Override
        public void onClick(View view) {
            if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
        }
    }

    String getItem(int id) {
        return mData.get(id);
    }

    public void setClickListener(ItemClickListener itemClickListener) {
        this.mClickListener = itemClickListener;
    }

    public interface ItemClickListener {
        void onItemClick(View view, int position);

        Cursor c = null;

    }

    private void setAnimation(View viewToAnimate, int position) {
        // If the bound view wasn't previously displayed on screen, it's animated
        if (position > lastPosition) {
            Animation animation = AnimationUtils.loadAnimation(context, android.R.anim.slide_in_left);
            viewToAnimate.startAnimation(animation);
            lastPosition = position;
        }
    }
}

用法：

childrenRvAdapter = new ChildrenRvAdapter(c, dataSource);
    childrenRvAdapter.setClickListener(this);
    rv_childrens.setAdapter(childrenRvAdapter);

Listview到Recycler视图的转换

1 个答案: