RecyclerView的adapter的实际使用方法

//这是平常的单条目（记得加布局管理器）
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.Holder> implements View.OnClickListener {
    private String[] mNames;
    public MyAdapter(String[] names){
        this.mNames = names;
    }

    @Override
    public MyAdapter.Holder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = View.inflate(parent.getContext(), R.layout.item, null);
        view.setOnClickListener(this);
        Holder holder = new Holder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(MyAdapter.Holder holder, int position) {
        holder.text.setText(mNames[position]);
        holder.itemView.setTag(position);
    }

    @Override
    public int getItemCount() {
        return mNames.length;
    }


    public class Holder extends RecyclerView.ViewHolder{

        private final TextView text;

        public Holder(View itemView) {
            super(itemView);
            text = itemView.findViewById(R.id.text_item);
        }
    }

    public interface OnItemClick{
        void setOnItemClick(View view,int position);
    }

    private  OnItemClick onItemClick;

    public void setOnItemClick(OnItemClick onItemClick) {
        this.onItemClick = onItemClick;
    }

    @Override
    public void onClick(View v) {
        if (onItemClick != null){
            onItemClick.setOnItemClick(v, (Integer) v.getTag());
        }
    }
}


//多条目写法（继承的RecyclerView.Adapter泛型发生改变，不去写死）

import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

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

    private String[] mNames;
    private static final int ONE_ITEM = 0;
    private static final int TWP_ITEM = 1;

    public MoreAdapter(String[] mNames) {
        this.mNames = mNames;
    }

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View view = null;
        if (i == ONE_ITEM) {
            view = View.inflate(viewGroup.getContext(), R.layout.one_item, null);
            OneHolder holder = new OneHolder(view);
            return holder;
        } else {
            view = View.inflate(viewGroup.getContext(), R.layout.two_item, null);
            TwoHolder holder = new TwoHolder(view);
            return holder;
        }
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int i) {
            if (viewHolder instanceof OneHolder){
                ((OneHolder) viewHolder).text.setText(mNames[i]);
            }else {
                ((TwoHolder) viewHolder).text2.setText(mNames[i]);
            }
    }

    @Override
    public int getItemCount() {
        return mNames.length;
    }

    @Override
    public int getItemViewType(int position) {
        if (position % 2 == 0) {
            return ONE_ITEM;
        } else {
            return TWP_ITEM;
        }
    }

    class OneHolder extends RecyclerView.ViewHolder {

        private final TextView text;

        public OneHolder(@NonNull View itemView) {
            super(itemView);
            text = itemView.findViewById(R.id.one_item);
        }

    }

    class TwoHolder extends RecyclerView.ViewHolder {

        private final TextView text2;

        public TwoHolder(@NonNull View itemView) {
            super(itemView);
            text2 = itemView.findViewById(R.id.two_item);
        }
    }


}

//瀑布流写法

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import java.util.ArrayList;
import java.util.Random;

public class FlowAdapter extends RecyclerView.Adapter<FlowAdapter.MyHolder> {

    private ArrayList<Integer> mList;
    public FlowAdapter(ArrayList<Integer> list){
        this.mList = list;
    }

    @Override
    public MyHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        //因为瀑布流展示效果涉及到了它的父类
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item2,parent,false);
        MyHolder holder = new MyHolder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(MyHolder holder, int position) {
        holder.mImage.setImageResource(mList.get(position));
        //LayoutParams里面封装队友控件设置宽高，居中方式等等
        ViewGroup.LayoutParams layoutParams = holder.itemView.getLayoutParams();
        Random random = new Random();
        int height = random.nextInt(400)+200;
        layoutParams.height = height;
        holder.itemView.setLayoutParams(layoutParams);
    }

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

    public class MyHolder extends RecyclerView.ViewHolder {

        private final ImageView mImage;

        public MyHolder(View itemView) {
            super(itemView);
            mImage = itemView.findViewById(R.id.text2_item);
        }
    }
}