精通RecyclerView：打造ListView、GridView、瀑布流；學會添加分割線、 添加刪除動畫 、Item點擊事件

轉載請註明出處：http://blog.csdn.net/linglongxin24/article/details/53126706
本文出自【DylanAndroid的博客】

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精通RecyclerView：打造ListView、GridView、瀑布流；學會添加分割線、 添加刪除動畫 、Item點擊事件

在上一篇Android用RecyclerView練手仿美團分類界面寫了RecyclerView的基本用法，
今天想想，在這裏重新學習一下RecyclerView的完整用法。包括如何打造一個普通的ListView和橫向的ListView、普通的GridView和橫向的GridView、如何添加分割線、
還有就是添加和刪除的動畫、以及如何設置Item的OnClick事件監聽。這裏包含了各種用法，也算是一個入門的用法，已經掌握的高手請略過。

先看總體效果圖

一.RecyclerView介紹

RecyclerView 是Android 5.0版本中新出現的東西，用來替代ListView和GridView的。

二.RecyclerView架構

RecyclerView使用佈局管理器LayoutManager和適配器Adapter的適配器模式去實現架構，不關心數據的來源。耦合性非常的底，用戶可以根據自己的用戶界面去實現相應的效果

三.RecyclerView的優點

• 1.RecyclerView內部已經強制使用VIewHolder，優化了對Item中View的複用。

• 2.提供了一個較爲靈活的佈局管理類，LayoutManager，用來控制RecyclerView是線性展示還是垂直展示，以及可以設置成瀑布流。並且提供了ItemDecoration這個類，來靈活的讓用戶來設置分割線。

• 3.用ItemAnimator可以對item進行佈局的刪減動畫效果。

四.RecyclerView實現三部曲

• 第一步：設置佈局管理器

  用來確定每一個item如何進行排列擺放:

  • LinearLayoutManager 相當於ListView的效果
  • GridLayoutManager相當於GridView的效果
  • StaggeredGridLayoutManager 瀑布流

• 第二步：添加分割線

  我們用到了網上流傳的萬能分割線DividerItemDecoration和DividerGridItemDecoration，首先在style.xml裏面定義分割線圖片：

  1.先在drawable中新建divider.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >
    <solid android:color="@color/colorAccent"/>
    <size android:height="1dp"
        android:width="1dp"/>
</shape>

    2.然後在style.xml中設置android:listDivider

        <item name="android:listDivider">@drawable/divider</item>

• 第三步：設置適配器

package cn.bluemobi.dylan.recyclerviewdemo2;

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

/**
 * RecyclerView的適配器
 * Created by yuandl on 2016-11-01.
 */

public class RvAdapter extends RecyclerView.Adapter<RvAdapter.MyViewHolder> {
    private Context context;
    private List<Integer> datas;

    /**
     * item的點擊事件的長按事件接口
     */
    private OnItemClickListener onItemClickListener;
    /**
     * 瀑布流時的item隨機高度
     */
    private List<Integer> heights = new ArrayList<>();

    /**
     * 不同的類型設置item不同的高度
     *
     * @param type
     */

    private int type = 0;

    public RvAdapter(Context context, List<Integer> datas) {
        this.context = context;
        this.datas = datas;
        for (int i : datas) {
            int height = (int) (Math.random() * 100 + 300);
            heights.add(height);
        }
    }

    public void setType(int type) {
        this.type = type;
    }

    /**
     * 設置點擊事件
     *
     * @param onItemClickListener
     */
    public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
        this.onItemClickListener = onItemClickListener;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View contentView = LayoutInflater.from(context).inflate(R.layout.item, parent, false);
        MyViewHolder viewHolder = new MyViewHolder(contentView);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, final int position) {
        RecyclerView.LayoutParams layoutParams;
        if (type == 0) {
            layoutParams = new RecyclerView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        } else if (type == 1) {
            layoutParams = new RecyclerView.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        } else {
            layoutParams = new RecyclerView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, heights.get(position));
            layoutParams.setMargins(2, 2, 2, 2);
        }
        holder.itemView.setLayoutParams(layoutParams);
        holder.imageView.setImageResource(datas.get(position));
        holder.tv.setText("分類" + position);
        /**設置item點擊監聽**/
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (onItemClickListener != null) {
                    onItemClickListener.onItemClickListener(position, datas.get(position));
                }
            }
        });

    }

    @Override
    public int getItemCount() {
        return datas == null ? 0 : datas.size();
    }

    /**
     * 用於緩存的ViewHolder
     */
    public class MyViewHolder extends RecyclerView.ViewHolder {
        private ImageView imageView;
        public TextView tv;

        public MyViewHolder(View itemView) {
            super(itemView);
            imageView = (ImageView) itemView.findViewById(R.id.iv);
            tv = (TextView) itemView.findViewById(R.id.tv);
        }
    }

    /**
     * 設置item監聽的接口
     */
    public interface OnItemClickListener {
        void onItemClickListener(int position, Integer data);

    }
}

五.打造各種效果

• 1.豎向的ListView

    rv.setBackgroundColor(Color.TRANSPARENT);
    rv.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));
    rvAdapter.setType(0);
    rv.removeItemDecoration(itemDecoration);
    rv.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT));
    itemDecoration = new DividerItemDecoration(this, DividerItemDecoration.VERTICAL_LIST);
    rv.addItemDecoration(itemDecoration);

• 2.橫向的ListView

   rvAdapter.setType(1);
   rv.removeItemDecoration(itemDecoration);
   rv.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT));
   rv.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));
   itemDecoration = new DividerItemDecoration(this, DividerItemDecoration.HORIZONTAL_LIST);
   rv.addItemDecoration(itemDecoration);

• 3.豎向的GridView

   rvAdapter.setType(1);
   rv.setBackgroundColor(Color.TRANSPARENT);
   rv.removeItemDecoration(itemDecoration);
   rv.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT));
   rv.setLayoutManager(new GridLayoutManager(this, 5));
   itemDecoration = new DividerGridItemDecoration(this);
   rv.addItemDecoration(itemDecoration);

• 4.橫向的GridView

    rvAdapter.setType(1);
    rv.setBackgroundColor(Color.TRANSPARENT);
    rv.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT));
    rv.removeItemDecoration(itemDecoration);
    rv.setLayoutManager(new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.HORIZONTAL));
    itemDecoration = new DividerGridItemDecoration(this);
    rv.addItemDecoration(itemDecoration);

• 5.豎向的瀑布流

     rvAdapter.setType(3);
     rv.setBackgroundColor(getResources().getColor(R.color.colorAccent));
     rv.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT));
     rv.removeItemDecoration(itemDecoration);
     rv.setLayoutManager(new StaggeredGridLayoutManager(5, StaggeredGridLayoutManager.VERTICAL));

• 6.添加和刪除動畫

       /**添加一個數據**/
       rvAdapter.notifyItemInserted(1);
       /**刪除一個數據**/
       rvAdapter.notifyItemRemoved(1);

六.GiHub