RecycleView的基本用法

一、RecycleView是android中一个很重要的高级控件，可以实现GridView,ListView,瀑布流等效果，实现了布局与Item，数据之间的分离，通过一个小案例掌握RecycleView的基本用法。

二、案例实现
1、RecycleView实现ListView
编码思路
1、导入库
点击File->Project Structure ->Dependencies->选择V7的recycleview.
2、定义MyAdapter继承RecycleView.Adapter类，泛型为RecycleView.ViewHolder，实现ViewHolder
3、LayoutManager为LinearLayoutManager
4、秒变GridView、水平的GridView的只要修改LayoutManager为

 case R.id.id_GridView:
                mRecyclerView.setLayoutManager(new GridLayoutManager(this, 3));
                break;
            case R.id.id_hor_GridView:
                mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(5, StaggeredGridLayoutManager.HORIZONTAL));
                break;

1、MyAdapter类

package com.kuxiao.trian.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.TextView;


import java.util.List;

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

    private Context mContext;

    private List<String> mData;

    private LayoutInflater mInflater;

    private MyAdapter.OnItemClickListener OnItemClickListener;


    public MyAdapter(Context mContext, List<String> mData) {
        this.mContext = mContext;
        this.mData = mData;
        this.mInflater = LayoutInflater.from(mContext);
    }


    @Override
    public MyAdapter.MyHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        MyHolder holder = new MyHolder(mInflater.inflate(R.layout.item, parent, false));
        return holder;
    }

    @Override
    public void onBindViewHolder(final MyHolder holder, final int position) {
        holder.mTextView.setText(mData.get(position));
        setUpItemClickListener(holder);
    }

    protected void setUpItemClickListener(final MyHolder holder) {
        if (OnItemClickListener !=  null)
        {
            holder.itemView.setOnClickListener(new View.OnClickListener() {
                 @Override
                 public void onClick(View v) {
                     int layoutPosition = holder.getLayoutPosition();
                     OnItemClickListener.onItemClick(v, layoutPosition);
                 }
             });
            holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
                @Override
                public boolean onLongClick(View v) {
                    int layoutPosition = holder.getLayoutPosition();
                    OnItemClickListener.onItemLongClick(v,layoutPosition);
                    return true;
                }
            });
        }
    }

    public void setOnItemClickListener(MyAdapter.OnItemClickListener onItemClickListener)
    {
        this.OnItemClickListener = onItemClickListener;
    }


    /**
     * 增加一项
     *
     * @param position
     */
    public void addItem(int position) {
        mData.add(position,"insert one");
        notifyItemInserted(position);
    }

    /**
     * 删除某项
     *
     * @param position
     */
    public void deleteItem(int position) {
        mData.remove(position);
        notifyItemRemoved(position);
    }


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

    class MyHolder extends RecyclerView.ViewHolder {

        TextView mTextView;

        public MyHolder(View itemView) {
            super(itemView);
            mTextView = (TextView) itemView.findViewById(R.id.id_tv_item);
        }
    }

    public interface OnItemClickListener {
        void onItemClick(View view,int position);
        void onItemLongClick(View view,int position);
    }
}

2、自定义分割线类（DividerItemDecoration类）

package com.kuxiao.trian.recycleview;

/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;

/**
 * This class is from the v7 samples of the Android SDK. It's not by me!
 * <p/>
 * See the license above for details.
 */
public class DividerItemDecoration extends RecyclerView.ItemDecoration
{

    private static final int[] ATTRS = new int[] { android.R.attr.listDivider };

    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;

    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;



    private Drawable mDivider;

    private int mOrientation;

    public DividerItemDecoration(Context context, int orientation)
    {
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        a.recycle();
        setOrientation(orientation);
    }

    public void setOrientation(int orientation)
    {
        if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST)
        {
            throw new IllegalArgumentException("invalid orientation");
        }
        mOrientation = orientation;
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent)
    {
        Log.v("recyclerview - itemdecoration", "onDraw()");
         if (mOrientation == VERTICAL_LIST) {
                drawVertical(c, parent);
            } else {
                drawHorizontal(c, parent);
            }
    }

    public void drawVertical(Canvas c, RecyclerView parent)
    {
        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();

        final int childCount = parent.getChildCount();

        for (int i = 0; i < childCount; i++)
        {
            final View child = parent.getChildAt(i);
            RecyclerView v = new RecyclerView(
                    parent.getContext());
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin;
            final int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    public void drawHorizontal(Canvas c, RecyclerView parent)
    {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();

        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++)
        {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, int itemPosition,
            RecyclerView parent)
    {
        if (mOrientation == VERTICAL_LIST)
        {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        } else
        {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }
}

3、MianActivity类

package com.kuxiao.trian.recycleview;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;

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

public class MainActivity extends AppCompatActivity {


    private RecyclerView mRecyclerView = null;
    private RecyclerView.LayoutManager mLayoutManager = null;
    private List<String> mData = null;
    private MyAdapter myAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();
        initView();

    }

    private void initData() {

        mData = new ArrayList<String>();

        for (int i = 'A'; i < 'z'; i++) {
            mData.add((char) i + "");
        }

    }

    private void initView() {

        mRecyclerView = (RecyclerView) findViewById(R.id.id_rv);
        //布局器
        mLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
       /* //自定义分割线
        RecyclerView.ItemDecoration  IteDecoration = new DividerItemDecoration(this,DividerItemDecoration.VERTICAL_LIST);
        mRecyclerView.addItemDecoration(IteDecoration);*/
        myAdapter = new MyAdapter(this, mData);
        mRecyclerView.setAdapter(myAdapter);
        mRecyclerView.setLayoutManager(mLayoutManager);
        mRecyclerView.setItemAnimator(new DefaultItemAnimator());
        myAdapter.setOnItemClickListener(new MyAdapter.OnItemClickListener() {
            @Override
            public void onItemClick(View view, int position) {
                Toast.makeText(MainActivity.this,"点击位置为" + position,Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onItemLongClick(View view, int position) {
                Toast.makeText(MainActivity.this,"长按的位置为" + position,Toast.LENGTH_SHORT).show();

            }
        });

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.mian, menu);
        return true;
    }


    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        switch (item.getItemId()) {
            case R.id.id_listview:
                mRecyclerView.setLayoutManager(mLayoutManager);
                break;

            case R.id.id_add:
                myAdapter.addItem(2);
                break;
            case R.id.id_delete:
               myAdapter.deleteItem(2);
                break;
            case R.id.id_GridView:
                mRecyclerView.setLayoutManager(new GridLayoutManager(this, 3));
                break;
            case R.id.id_hor_GridView:
                mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(5, StaggeredGridLayoutManager.HORIZONTAL));
                break;
            case R.id.id_stagger:
                Intent intent = new Intent(this,MainActivity1.class);
                startActivity(intent);
                break;
            case R.id.id_settring:
                break;
        }

        return super.onOptionsItemSelected(item);
    }
}

3、瀑布流效果是改变每一个Item的高度

package com.kuxiao.trian.recycleview;


import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

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

public class MyAdapter1 extends MyAdapter {

    private Context mContext;
    private static final String TAG = "MyAdapter1";
    private List<Integer> mHiegths;

    public MyAdapter1(Context mContext, List<String> mData) {
        super(mContext, mData);
        this.mContext = mContext;
        mHiegths = new ArrayList<Integer>();
        for (int i = 0; i < mData.size(); i++){

            mHiegths.add((int) (100 + Math.random()*300));

        }

    }

    @Override
    public void onBindViewHolder(MyHolder holder, int position) {
        super.onBindViewHolder(holder,position);
       MyHolder myHolder = (MyHolder) holder;
        ViewGroup.LayoutParams lp = myHolder.itemView.getLayoutParams();
        lp.height = mHiegths.get(position);
        myHolder.itemView.setLayoutParams(lp);
       // setUpItemClickListener(myHolder);
    }

}

注意事项：
1、自定义分割线用的属性为 android:listDivider去获取Drawable.

 <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="android:listDivider">@drawable/divider01</item>

    </style>

divider01代码

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

    <size android:height="4dp" />
    <gradient
        android:centerColor="#ff0000ff"
        android:endColor="#ffff0000"
        android:startColor="#ff00ff00"
        android:type="linear" />

</shape>

2、增加与删除Item操作与BaseAdapter的区别的NotifyItemInserted()
NotifyDataChange()

  /**增加项
  */
 public void addItem(int position) {
        mData.add(position,"insert one");
        notifyItemInserted(position);
    }

    /**
     * 删除某项
     *
     * @param position
     */
    public void deleteItem(int position) {
        mData.remove(position);
        notifyItemRemoved(position);
    }

3、Item点击与长按事件实现用接口回调

   //回调接口
    public interface OnItemClickListener {
        void onItemClick(View view,int position);
        void onItemLongClick(View view,int position);
    }
  //设置接口
   public void setOnItemClickListener
(MyAdapter.OnItemClickListener onItemClickListener)
    {
        this.OnItemClickListener = onItemClickListener;
    }

  //绑定
  public void onBindViewHolder(final MyHolder holder, final int position) {
        holder.mTextView.setText(mData.get(position));
        setUpItemClickListener(holder);
    }

    protected void setUpItemClickListener(final MyHolder holder) {
        if (OnItemClickListener !=  null)
        {
            holder.itemView.setOnClickListener(new View.OnClickListener() {
                 @Override
                 public void onClick(View v) {
                     int layoutPosition = holder.getLayoutPosition();
                     OnItemClickListener.onItemClick(v, layoutPosition);
                 }
             });
            holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
                @Override
                public boolean onLongClick(View v) {
                    int layoutPosition = holder.getLayoutPosition();
                    OnItemClickListener.onItemLongClick(v,layoutPosition);
                    return true;
                }
            });
        }
    }

使用代码

myAdapter1.setOnItemClickListener(new MyAdapter.OnItemClickListener() {
            @Override
            public void onItemClick(View view, int position) {
                   myAdapter1.addItem(position);
            }

            @Override
            public void onItemLongClick(View view, int position) {
                myAdapter1.deleteItem(position);
            }
        });