下圖是淘寶上瀑布流的一個應用場景，今天我們就來用Recycler View實現以下瀑布流效果

一：建立Activity

activity中 核心程式碼為

mRvPu.setLayoutManager(new StaggeredGridLayoutManager(2,StaggeredGridLayoutManager.VERTICAL));

該行程式碼使用layoutmanager實現一個兩列的垂直佈局，API解釋如下

new StaggeredGridLayoutManager(行數/列數,水平/垂直)

package com.example.fitz.demo4.recycleView;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;

import com.example.fitz.demo4.R;

public class PuRecyclerViewActivity extends AppCompatActivity {
    private RecyclerView mRvPu;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_pu_recycler_view);
        mRvPu=(RecyclerView)findViewById(R.id.rv_pu);
        //設定佈局方式,2列，垂直
        mRvPu.setLayoutManager(new StaggeredGridLayoutManager(2,StaggeredGridLayoutManager.VERTICAL));
        mRvPu.setAdapter(new StaggeredGridAdapter(PuRecyclerViewActivity.this));
    }
}
 

二：Adapter的構建

沒什麼特別的地方

package com.example.fitz.demo4.recycleView;

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.AdapterView;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import com.example.fitz.demo4.R;

import java.util.ArrayList;
import java.util.List;

public class StaggeredGridAdapter extends RecyclerView.Adapter<StaggeredGridAdapter.LinearViewHolder>{

    private Context mContext;
    private AdapterView.OnItemClickListener mListener;
    private List<String> list=new ArrayList<>();

    public StaggeredGridAdapter(Context mContext) {
        this.mContext = mContext;
        for(int i=0;i<30;i++){
            list.add(String.format("%s-%s", i/10+1,i));
        }
    }

    @Override
    public StaggeredGridAdapter.LinearViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return new LinearViewHolder(LayoutInflater.from(mContext).inflate(R.layout.layout_staggere_grid_item,parent,false));
    }

    @Override
    public void onBindViewHolder(StaggeredGridAdapter.LinearViewHolder holder, int position) {
        if(position%2==0){
            holder.mImageView.setImageResource(R.drawable.baby1);
        }
        else{
            holder.mImageView.setImageResource(R.drawable.baby2);
        }

    }

    @Override
    public int getItemCount() {
        return 30;
    }

    class LinearViewHolder extends RecyclerView.ViewHolder{
        private ImageView mImageView;
        public LinearViewHolder(View itemView){
            super(itemView);
            mImageView=(ImageView) itemView.findViewById(R.id.iv);
        }
    }
}
 

三：佈局檔案 layout_staggere_grid_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

<ImageView
    android:id="@+id/iv"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_margin="2dp"
    android:scaleType="centerCrop"/>
</LinearLayout>
 

當執行時候可得到如下效果，自此一個瀑布流就實現了，之後可以根據業務場景寫點選事件或是UI上加入TextView做其他用途等，這裡有可能會有OOM問題，下次在講啦