recycleview瀑布流Item适应图片

package com.example.pei.recyclerviewdemo;

import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.Display;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.Toast;

/**
 * Created by
 */

public class RVAdapter extends RecyclerView.Adapter<RVAdapter.ViewHolder>{
    int a[] = {
            R.mipmap.d,
            R.mipmap.e,
            R.mipmap.f,
            R.mipmap.d,
            R.mipmap.e,
            R.mipmap.f,
            R.mipmap.d,
            R.mipmap.e,
            R.mipmap.f
            };

    Context mContext;

    public RVAdapter(Context context) {
        mContext = context;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(mContext).inflate(R.layout.item_image,null);
        ViewHolder viewHolder = new ViewHolder(view);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {

        holder.mImageView.setImageResource(a[position]);
        holder.mImageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.d("RVAdapter", "position:..." + position);
            }
        });
        ViewGroup.LayoutParams params = holder.mImageView.getLayoutParams();

        Bitmap bitmap = BitmapFactory.decodeResource(mContext.getResources(),a[position]);
        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        //拿到屏幕宽
        int screenWidth = ((Activity) holder.mImageView.getContext())
                .getWindowManager().getDefaultDisplay().getWidth();
        float aaa = (float)screenWidth/3;
        //图片压缩比例
        float bili = (float) (width/aaa);
        params.height = (int) (height/bili);
        params.width = (int) (width/bili);
        holder.mImageView.setLayoutParams(params);

    }

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

    public class ViewHolder extends RecyclerView.ViewHolder {

        private ImageView mImageView;

        public ViewHolder(View itemView) {
            super(itemView);
            mImageView = (ImageView) itemView.findViewById(R.id.image_main);



    }
    }
}

为了防止以瀑布流显示图片的时候,图片会有空白区域.

本来以为会出现特殊情况导致一列的图片超过其他列图片高度太多,后来发现不会发生,recycleview已经考虑到了这个.nice

item的position不会因为recycleview的自动排列而乱了数组中的位置